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Environment - General [1989]
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Environment - General [1989]
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Allan D. Bromley Files
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Originally Processed With FOIA(s): FOIA Number: 2005-0336-F 2005-0336-F FOIA MARKER This is not a textual record. This is used as an administrative marker by the George Bush Presidential Library Staff. Record Group/Collection: George H.W. Bush Presidential Records Collection/Office of Origin: Science and Technology Policy, Office of (OSTP) Series: Bromley, D. Allan, Files Subseries: Global Climate Change Files OA/ID Number: 62047 Folder ID Number: 62047-001 Folder Title: Environment - General [1989] Stack: Row: Section: Shelf: Position: 0 0 0 0 Withdrawal/Redaction Sheet (George Bush Library) Document No. Subject/Title of Document Date Restriction Class. and Type 01. Memorandum To: President Bush From: Domestic Policy Council 3/3/89 (b)(1) Re: Hazardous Waste Export (4 pp.) Collection: Record Group: Bush Presidential Records Office: Science and Technology Policy, Office of (OSTP) Series: Bromley, D. Allan, Files Subseries: General Science Files WHORM Cat.: File Location: Environment General [1989] Date Closed: 4/1/2010 OA/ID Number: 62047-001 FOIA/SYS Case #: 2005-0336-F Appeal Case #: Re-review Case #: Appeal Disposition: P-2/P-5 Review Case #: Disposition Date: AR Case #: MR Case #: AR Disposition: MR Disposition: AR Disposition Date: MR Disposition Date: RESTRICTION CODES Presidential Records Act [44 U.S.C. 2204(a)] Freedom of Information Act - [5 U.S.C. 552(b)] P-1 National Security Classified Information [(a)(1) of the PRA] (b)(1) National security classified information [(b)(1) of the FOIA] P-2 Relating to the appointment to Federal office [(a)(2) of the PRA] (b)(2) Release would disclose internal personnel rules and practices of an P-3 Release would violate a Federal statute [(a)(3) of the PRA] agency [(b)(2) of the FOIA] P-4 Release would disclose trade secrets or confidential commercial or (b)(3) Release would violate a Federal statute [(b)(3) of the FOIA] financial information [(a)(4) of the PRA] (b)(4) Release would disclose trade secrets or confidential or financial P-5 Release would disclose confidential advice between the President information [(b)(4) of the FOIA] and his advisors, or between such advisors [a)(5) of the PRA] (b)(6) Release would constitute a clearly unwarranted invasion of P-6 Release would constitute a clearly unwarranted invasion of personal privacy [(b)(6) of the FOIA] personal privacy [(a)(6) of the PRA] (b)(7) Release would disclose information compiled for law enforcement purposes [(b)(7) of the FOIA] C. Closed in accordance with restrictions contained in donor's deed of (b)(8) Release would disclose information concerning the regulation of gift. financial institutions [(b)(8) of the FOIA] (b)(9) Release would disclose geological or geophysical information PRM. Removed as a personal record misfile. THE WHITE HOUSE WASHINGTON November 29, 1989 CONFIDENTIAL Determined NOT to be National Security Classified Marking By MB (NLGB) on 4/1/10 Dear Dave: This is a belated response to your letter of October 31, which arrived while I was in the Netherlands at a huge meeting on global warming. There are, in fact, two positions that I think you might be interested in, one open at the moment, and one that will become open next September. The first is that of Director of the Office of Energy Research in the Department of Energy. As you know, Bob Hunter terminated his appointment at the request of Admiral Watkins abruptly a few weeks ago, and Jim Decker is again serving as Acting Director. This causes me some considerable difficulty, because Jim was all set to accept appointment as Assistant Director for Physical Science and Engineering in my office and now feels committed to holding down the fort until a replacement is selected by the Admiral. I know that Admiral Watkins has talked with Al Neuharth, who is currently director of the Sandia Laboratories, and with Harold Fortzen, who is currently with Battelle, but in both cases has received a negative response, so that he is still looking. The second position is that of Director of the National Science Foundation which will become vacant next September when Erich Bloch completes his six years in the post. A major search committee activity will be undertaken, starting in the very near future. It will be chaired by Dr. Mary Good, of Allied Signal, who is currently chairman of the National Science Board. If either of these positions are of interest to you, I would suggest that you immediately get a resume to Admiral James D. Watkins, Secretary of Energy, and to Dr. Mary Good, Chairman, National Science Board, as soon as possible, indicating that I suggested that you should do so. Unhappily, in both of these cases, and indeed in my own, the situation does not promise to be as much fun as it was in Jay Keyworth's time, when research budgets were increasing at a reasonably healthy rate. I suspect that the next few years will be difficult ones, with a number of very hard budget decisions being required each year -- decisions that will make the scientific community and the Congress and, in fact, everyone else, unhappy. This is really the first time, since the War, when I suspect that it will be the case that even very high-quality projects will not be able to move forward, if not immediately then eventually, because we simply have more high-quality people and projects than can be supported with any reasonable extrapolation of current budgets. On the other hand, this is when leadership is required, and I think that you could have a very real impact if you were to find yourself in either of these positions. The membership of the President's Council of Advisers on Science and Technology (PCAST) has now been fixed and has involved a remarkable amount of balancing and adjusting for geographical, professional and an amazing array of other attributes. Unfortunately, you were not included in the final list of initial appointees, although that certainly does not imply that with the expected turnover that you will not become a member of that group in the not too distant future. I have now completed the senior staff at the Presidential appointment level in my own office. Jim Wyngaarden and Tom Ratchford were confirmed by the Senate at 1:00 a.m. on Saturday morning, November 18, and your colleague, Eugene Wong from Berkeley, will be confirmed as Associate Director for Physical Science and Engineering, and Dr. William Phillips, formerly executive vice president of both Mallincropt and DuPont, as well as chairman of the chemistry department at Washington University in St. Louis, will be confirmed as Associate Director for Industrial Technology, very soon after the Senate reconvenes early in the new year. I believe that this group has a remarkable degree of complementarity and that, together with me, will represent a collegial group that will be able to address the problems that boil up through the system to the Presidential level in reasonable fashion. Please let me know what you decide to do about the DOE and NSF positions. Let me also emphasize that, in both cases, this is still to be considered as confidential and, in particular, in the NSF case, the search procedure has not yet been announced but I suspect will be early in the new year. With warmest best wishes to both you and Virginia, and with the hope that the remainder of your stay in Berlin will be a pleasant and rewarding one, Sincerely yours, from D. Allan Bromley Assistant to the President for Science and Technology Professor David A. Shirley Free University of Berlin Faculty of Physics Institute for Atomic and Particle Physics WE 1, Arnimallee 14, 1000 Berlin 33 Federal Republic of Germany CONFIDENTIAL Determined NOT to be National Security Classified Marking By MB (NLGB) on 4/1/10 FREIE UNIVERSITÄT BERLIN FU BERLIN Fachbereich Physik Institut für Atom- und Festkörperphysik (WE 1) October 31, 1989 Freie Universität Berlin, Fachbereich Physik Tel.: (030) 838 WE 1, Arnimallee 14, 1000 Berlin 33 (Tx 17308622 + Ttx 308622=fuphysk) Dr. D. Allan Bromley PERSONAL Assistant to the President for Science and Technology Room 358, Old Executive Office Building Washington, D.C. 20500 Dear Allan, I'm writing for two reasons. First, to send greetings from Berlin, where we're comfortably ensconced doing science, seeing Europe at a more leisurely pace, and having the time of our lives! The second reason is to let you know that I have become quite serious about seeking a more challenging position than the professorship which awaits me in Berkeley. The difference from earlier this year is that now I'm thinking of a permanent move to a position in science or university administration. I'm writing to you both as a friend and because I recall that it was Jay Keyworth who ordered Hermann to go and be the director of CEBAF! Thus I surmise that knowledge of openings will reach your Office. Please remember me if something suitable for this ex lab director comes along. To minimize the trauma (or celebrations) in Berkeley, I'd like to keep this process confidential. Anything sent to my Ber- keley address will be forwarded discreetly by my secretary. Al- ternatively, my home address here is Garystrasse 65 1000 Berlin 33 W. Germany. My home direct-dial telephone number is 011 49 30 8313523, and my e-mail address (bitnet only) is st%"[email protected]" all of which is needed. Please share this information with anyone who has an appropriate job to offer, and I'll send a c.v. and refer- ences on request. I have heard that you are doing a great many good things for the country in your new role: count me among your many fans! Thanks again for your responses this last summer. Cordially, Dave David A. Shirley Withdrawal/Redaction Sheet (George Bush Library) Document No. Subject/Title of Document Date Restriction Class. and Type 02. Memorandum To: John Sununu From: Allan Bromley 11/3/89 (b)(1) Re: EPA Regulations (1 pp.) Collection: Record Group: Bush Presidential Records Office: Science and Technology Policy, Office of (OSTP) Series: Bromley, D. Allan, Files Subseries: General Science Files WHORM Cat.: File Location: Environment - General [1989] Date Closed: 4/1/2010 OA/ID Number: 62047-001 FOIA/SYS Case #: 2005-0336-F Appeal Case #: Re-review Case #: Appeal Disposition: P-2/P-5 Review Case #: Disposition Date: AR Case #: MR Case #: AR Disposition: MR Disposition: AR Disposition Date: MR Disposition Date: RESTRICTION CODES Presidential Records Act - [44 U.S.C. 2204(a)] Freedom of Information Act - [5 U.S.C. 552(b)] P-1 National Security Classified Information [(a)(1) of the PRA] (b)(1) National security classified information [(b)(1) of the FOIA] P-2 Relating to the appointment to Federal office [(a)(2) of the PRA] (b)(2) Release would disclose internal personnel rules and practices of an P-3 Release would violate a Federal statute [(a)(3) of the PRA] agency [(b)(2) of the FOIA] P-4 Release would disclose trade secrets or confidential commercial or (b)(3) Release would violate a Federal statute [(b)(3) of the FOIA] financial information [(a)(4) of the PRA] (b)(4) Release would disclose trade secrets or confidential or financial P-5 Release would disclose confidential advice between the President information [(b)(4) of the FOIA] and his advisors, or between such advisors [a)(5) of the PRA] (b)(6) Release would constitute a clearly unwarranted invasion of P-6 Release would constitute a clearly unwarranted invasion of personal privacy [(b)(6) of the FOIA] personal privacy [(a)(6) of the PRA] (b)(7) Release would disclose information compiled for law enforcement purposes [(b)(7) of the FOIA] C. Closed in accordance with restrictions contained in donor's deed of (b)(8) Release would disclose information concerning the regulation of gift. financial institutions [(b)(8) of the FOIA] (b)(9) Release would disclose geological or geophysical information PRM. Removed as a personal record misfile. Withdrawal/Redaction Sheet (George Bush Library) Document No. Subject/Title of Document Date Restriction Class. and Type 03. Memorandum To: John Sununu From: Allan Bromley 11/29/89 (b)(1) Re: Impact of Launches on Stratospheric Ozone (1 pp.) Collection: Record Group: Bush Presidential Records Office: Science and Technology Policy, Office of (OSTP) Series: Bromley, D. Allan, Files Subseries: General Science Files WHORM Cat.: File Location: Environment - General [1989] Date Closed: 4/1/2010 OA/ID Number: 62047-001 FOIA/SYS Case #: 2005-0336-F Appeal Case #: Re-review Case #: Appeal Disposition: P-2/P-5 Review Case #: Disposition Date: AR Case #: MR Case #: AR Disposition: MR Disposition: AR Disposition Date: MR Disposition Date: RESTRICTION CODES Presidential Records Act [44 U.S.C. 2204(a)] Freedom of Information Act [5 U.S.C. 552(b)] P-1 National Security Classified Information [(a)(1) of the PRA] (b)(1) National security classified information [(b)(1) of the FOIA] P-2 Relating to the appointment to Federal office [(a)(2) of the PRA] (b)(2) Release would disclose internal personnel rules and practices of an P-3 Release would violate a Federal statute [(a)(3) of the PRA] agency [(b)(2) of the FOIA] P-4 Release would disclose trade secrets or confidential commercial or (b)(3) Release would violate a Federal statute [(b)(3) of the FOIA] financial information [(a)(4) of the PRA] (b)(4) Release would disclose trade secrets or confidential or financial P-5 Release would disclose confidential advice between the President information [(b)(4) of the FOIA] and his advisors, or between such advisors [a)(5) of the PRA] (b)(6) Release would constitute a clearly unwarranted invasion of P-6 Release would constitute a clearly unwarranted invasion of personal privacy [(b)(6) of the FOIA] personal privacy [(a)(6) of the PRA] (b)(7) Release would disclose information compiled for law enforcement purposes [(b)(7) of the FOIA] C. Closed in accordance with restrictions contained in donor's deed of (b)(8) Release would disclose information concerning the regulation of gift. financial institutions [(b)(8) of the FOIA] (b)(9) Release would disclose geological or geophysical information PRM. Removed as a personal record misfile. Withdrawal/Redaction Sheet (George Bush Library) Document No. Subject/Title of Document Date Restriction Class. and Type 04. Memorandum To: James Baker From: Allan Bromley 11/15/89 (b)(6) Re: Frederick Bernthal (1 pp.) Collection: Record Group: Bush Presidential Records Office: Science and Technology Policy, Office of (OSTP) Series: Bromley, D. Allan, Files Subseries: General Science Files WHORM Cat.: File Location: Environment - General [1989] Date Closed: 4/1/2010 OA/ID Number: 62047-001 FOIA/SYS Case #: 2005-0336-F Appeal Case #: Re-review Case #: Appeal Disposition: P-2/P-5 Review Case #: Disposition Date: AR Case #: MR Case #: AR Disposition: MR Disposition: AR Disposition Date: MR Disposition Date: RESTRICTION CODES Presidential Records Act [44 U.S.C. 2204(a)] Freedom of Information Act [5 U.S.C. 552(b)] P-1 National Security Classified Information [(a)(1) of the PRA] (b)(1) National security classified information [(b)(1) of the FOIA] P-2 Relating to the appointment to Federal office [(a)(2) of the PRA] (b)(2) Release would disclose internal personnel rules and practices of an P-3 Release would violate a Federal statute [(a)(3) of the PRA] agency [(b)(2) of the FOIA] P-4 Release would disclose trade secrets or confidential commercial or (b)(3) Release would violate a Federal statute [(b)(3) of the FOIA] financial information [(a)(4) of the PRA] (b)(4) Release would disclose trade secrets or confidential or financial P-5 Release would disclose confidential advice between the President information [(b)(4) of the FOIA] and his advisors, or between such advisors [a)(5) of the PRA] (b)(6) Release would constitute a clearly unwarranted invasion of P-6 Release would constitute a clearly unwarranted invasion of personal privacy [(b)(6) of the FOIA] personal privacy [(a)(6) of the PRA] (b)(7) Release would disclose information compiled for law enforcement purposes [(b)(7) of the FOIA] C. Closed in accordance with restrictions contained in donor's deed of (b)(8) Release would disclose information concerning the regulation of gift. financial institutions [(b)(8) of the FOIA] (b)(9) Release would disclose geological or geophysical information PRM. Removed as a personal record misfile. THE WHITE HOUSE WASHINGTON November 3, 1989 MEMORANDUM FOR JOHN H. SUNUNU FROM: D. ALLAN BROMLEY Auan SUBJECT: NEW, NOVEMBER 1, EPA REGULATIONS ON RADIONUCLIDE EMISSIONS A great deal of controversy surrounds EPA's promulgation of their new standard on radionuclides where it concerns NRC-licensees. A 90-day stay for reconsideration of this category of emitters was requested but the justification given was focused mainly on the nuclear medicine facilities alone. The main issue should have been the dual regulating of all the NRC-licensed facilities by EPA as well as by the NRC. Some would argue that the best way to handle the situation now, is to have a jointly signed letter go to the Congress requesting legislation to eliminate dual regulation for radionuclides. The sponsors of the letter would be NRC, DOE, NIH, and EPA. (EPA agrees to do this but they have a different text than the other agencies.) Since a similar tactic was used for mixed waste and could never get resolved by Congress, I don't believe this process has any chance of success -- no matter how many stays EPA requests from the Court. When the stays cease, EPA will then have to regulate unless the Court rules otherwise. UNLIKELY! I believe there is a way to resolve this problem. It is a regulatory, not legislative, solution. My staff informs me that OMB's regulatory oversight group (OIRA) can require EPA to submit to OMB's OIRA the technical justification for such dual regulation of the NRC-licensees. A reason such as EPA gave in their new regulation (see attached) -- "EPA has decided to regulate this category to insure that the current levels of emissions are not increased." -- does not form the basis for the duplication and redundancy the dual monitoring would create. Assuming EPA cannot make an adequate justification, OIRA can then require the removal of that category -- NRC-licensees -- from these new radionuclide regulations. Attachments 10 mrem/y ede, will protect public health with an ample margin of safety. EPA has decided to regulate this category to insure that the current levels of emissions are not increased. The requirements of the rule assure that UFC facilities will keep emissions at or below the level of the standard, thereby insuring an ample margin of safety. The reporting provisions also provide the public with information on the emissions from the facility and provides them with assurance that the emissions will remain safe with an ample margin of safety, regardless of changes in the facility or the local population. Moreover, because each facility subject to this rule must demonstrate compliance with the 10 mrem/y ede emissions standard, it is likely that most, if not all, exposed individuals will receive a dose significantly less than 10 mrem/y ede. Therefore, EPA is promulgating a NESHAP mandating that radionuclide emissions from UFC facilities shall not cause any individual to receive a dose greater than 10 mrem/y ede. 4. Implementation EPA has determined that the same level of regulation is appropriate for both UFC facilities and NRC- licensees. Therefore, EPA has removed the exemption for UFC facilities in the NRC-licensee NESHAP and will regulate them exactly the same as other licensees, including reporting and recordkeeping requirements. EPA approves the use of the current version of NRC regulatory guidances for use in determining the emissions from 77 EPA's Radionuclide Emission Standard SYNOPSIS: Released 11/1/89 sets a 10m rem/yr limit on nuclear licensees' radionuclide emissions. A 90-day stay for reconsideration (with a 60-day comment period) was requsted for NRC licensees, ostensibly due to "recent" input from NIH and NRC regarding duplicative regulation and negative effects of the rule on medical treatment. However, the wording of the stay is unclear whether nuclear power plants are included in the reconsideration. CONCERNS UNDER THE NEW RULE: Dual regulation of nuclear power facilities would continue. Additionally, states may seize the opportunity to set more stringent limits. This rule sets an emissions limit despite EPA having determined that the risks from our plants "are acceptable" (p. 73 of new rule). However, other source categories with acceptable risks were not regulated under the Benzene policy, which EPA cites as its fundmental policy. In addition, this ruling appears to be counter to the intent of the Clean Air Act which requires regulation to be based on control of risk. The reason given by EPA for setting a limit for nuclear plants is "to insure that the current levels of emissions are not increased" (p. 77 of new rule). No justification is provided to substantiate the basis for that speculation. ALARA applies to nuclear plants under NRC rules. EPA recently has been expressing concern to avoid dual regulation, but their actions indicate they insist on EPA regulation of all emissions despite creation of a dual regulation situation. EPA appears unwilling to agree with NRC, DOE, and HHS in preparing a joint letter to Congress on the inadvisability of dual regulation and asking Congress to resolve. NRC, DOE, and HHS are clearly in support of eliminating dual regulation. RESOLUTION: EPA should decide that the existing EPA and NRC regulations for radionuclide emissions from commercial nuclear power plants and fuel fabrication facilities are properly controlling the public health risks. Additional regulation for these facilities should not be imposed because it will expend regulatory and industry resources and will not result in human health benefit. This approach 1s proper because 1) it complies with the Clean Air Act, 2) complies with the court's ruling in the Vinyl Chloride Case, and 3) the current EPA and NRC regulations very effectively control the risks for nuclear power plants. Environmental Protection Public Affairs (A-107) Agency Washington DO 20460 EPA Environmental News FOR RELEASE: WEDNESDAY, NOVEMBER 1, 1989 EPA SETS NEW RULES FOR RADIOACTIVITY FROM INDUSTRIAL SOURCES Dave Ryan (202) 382-2981 Final rules controlling radon and other radionuclide emissions from. industrial sources such as nuclear weapons plants, nuclear power plants and uranium mines were announced today by the U.S. Environmental Protection Agency. A radionuclide is a type of atom which spontaneously disintegrates into a different atom. People are exposed every day to radionuclides from a variety of natural and manmade sources. Natural sources of radiation include cosmic rays, radon gas and other terrestrial sources. Manmade sources include medical and dental X-rays, fallout from above-ground nuclear weapons testing and industrial facilities. Today's air pollution rules apply only to airborne releases from industrial facilities. Industry uses hundreds of different radionuclides in solid, liquid and gaseous forms. Industrial radionuclide emissions occur either as a result of an inability to contain the radioactive materials or as an unintended consequence of other activity, such as radionuclide emissions (usually radon) from mining or milling. An example of this second category is phosphogypsum piles. These piles emit radon because radium (from which radon gas is produced by radioactive decay) is found naturally in the same soils that are the source of phosphate rock. "Today's rules will protect public health from the risks of industrial radioactivity," said William G. Rosenberg, EPA Assistant Administrator for Air and Radiation. "As a result of these regulations, over 90 percent of all Americans in the vicinity of these industries will have less than one chance in a million of contracting fatal cancer from radionuclides." Numerous studies have demonstrated that radiation is a carcinogen. Although hereditary and developmental effects were considered in this rulemaking, cancer generally occurs more often and its effects are more severe. EPA believes that the level of protection mandated by this rule against cancer is sufficiently stringent to protect against hereditary and developmental affects. (more) -2- Rosenberg expressed frustration with the hurdles EPA must overcome in protecting risks: the public from radioactive and other hazardous air pollutant "Radionuclides provide a good example of the difficulties EPA faces in trying to reduce hazardous air emissions under the existing Clean Air Act. EPA officially designated radionuclides as hazardous air pollutants in 1979 and proposed standards for them in 1983. Yet lengthy litigation and related battles on health risk assessment issues has meant it's taken 10 years to get final rules on the books. "Since the Clean Air Act was passed in 1970, EPA, despite its best efforts, has been able to regulate only eight hazardous air pollutants. Reducing hazardous emissions under the current legislative structure and various court mandates is a lengthy, complex and cumbersome process, due in part to unresolved debate on acceptable levels of risk. The air toxics portion of President Bush's clean air proposal is a much better way to go. The President's bill gives Americans significant protection from toxic emissions right up front through the use of maximum achievable pollution-control technology. I urge speedy Congressional action to pass the President's bill to give Americans the health and environmental protection they want." Today's rule covers an estimated 6300 facilities in the following source categories: Source Category Approximate number of active facilities 1. Nuclear Regulatory Commission 6000 and non-Department of Energy federal facilities 2. Nuclear power reactors & 135 their support facilities 3. Disposal of uranium-mill 46 tailings piles 4. Department of Energy 45 facilities 3. Phosphogypsum piles 40 6. Licensed uranium-mill- 4 tailings piles 7. Elemental phosphorus 5 plants (more) -3- 8. Department of Energy radon 5 sources 9. Underground uranium mines 15 : These final regulations are issued under authority of the National Emissions Standards for Hazardous Air Pollutants provision of the Clean Air Act (Section 112). Under this section, EPA is required to establish emission standards for hazardous air pollutants at a level which provides an ample margin of safety to protect public health. Radionuclides are the second set of hazardous air pollutant regulations issued (after those set for benzene in August) since the landmark 1987 ruling by the Federal Appeals Court of Washington, D.C., on vinyl chloride. In that decision, the court mandated a two-step process for regulating hazardous air pollutants under Section 112. In the first step, EPA must establish an "acceptable" level of risk based solely on health considerations. In the second step, the Agency must then set enforceable standards that provide an "ample margin of safety" to the public. In determining the ample margin of safety, EPA may take pollution-control costs and technological feasibility into consideration. The final enforceable standard developed in the second step can be tougher, but not weaker than, the "acceptable" level of risk developed in the first stap. In protecting public health with an ample margin of safety under this rule, EPA is seeking to protect the greatest number of people possible, BO that their lifetime risk of developing cancer from these sources is less than one in a million. EPA is limiting the estimated risk of a person living in close proximity to a radionuclide emission source to no greater than approximately one in 10,000, assuming that person was exposed to the maximum pollutant concentrations for 70 years. The NRC-licensees source category covers a large variety of different types of facilities licensed to process radioactive material, including hospitals, radiopharmaceutical manufactureres, laboratories and research reactors. EPA has granted a reconsideration on this source category due to some recent information supplied by NRC and the National Institute of Health, indicating that this rule may adversely affect the ability of some medical facilities to use certain types of radiotherapy. In addition, the reconsideration will examine ways to reduce the regulatory burden caused by the dual regulation of these facilities by EPA and NRC. EPA is also issuing a 3 month stay of this part of the rule as provided in the Clean Air Act. (more) -4- Besides radionuclides, EPA has proposed or set final uniform, national hazardous air pollutant emission standards for asbestos, beryllium, emissions. mercury, vinyl chloride, arsenic, benzene and coke oven The final rules will appear soon in the Federal Register. For further information, contact Terrence McLaughlin, Environmental Standards Branch, Criteria and Standards Division (ANR-460), Office of Radiation Programs, Environmental Protection Agency, Washington, D.C. 20460; or call 202-475-9610. ### individual risk to any individual is approximately 1.5x10⁻⁶. In establishing the policy for setting NESHAPs in the context of benzene, the Agency determined that emissions resulting in a lifetime MIR no greater than approximately 1x10⁻⁴ are presumptively acceptable. In light of the numerous uncertainties in both establishing the parameters for the risk assessment and in modelling actual emissions and exposure, as well as the recognition that in achieving compliance, sources will generally control so as to ensure a buffer exists below the actual level of a standard, EPA judges that the MIR of 1.5x10⁻⁴ is essentially equivalent to the presumptively safe level of approximately 1x10⁻⁴. EPA then considered the other risk factors in order to make an overall decision on acceptability. The estimated annual incidence is 0.1 fatal cancer per year, and approximately 99% of that risk is borne by people whose risk is less than 1x10⁻⁶. Only 60 individuals incur a risk greater than 1x10⁻⁶, and the incidence in the level greater than 1x10⁻⁶ is only 0.00093. After examining these factors, the Administrator has determined that the baseline risks from UFC facilities are acceptable. Livel Cycle Uranium 73 H-79-11 ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 61 National Emission Standards for Hazardous Air Pollutants; Regulation of Radionuclides AGENCY: Environmental Protection Agency [EPA] ACTION: Final Rule and Notice of Reconsideration SUMMARY: This notice announces the Administrator's fina decisions on National Emission Standards for Hazardous Air Pollutants (NESHAPs) under Section 112 of the Clean Air Act for emissions of radionuclides from the following source categories: DOE Facilities, Licensees of the Nuclear Regulatory Commission and Non-DOE Federal Facilities, Uranium Fuel Cycle Facilities, Elemental Phosphorus Plants, Coal-Fired Boilers, High-level Nuclear Waste Disposal Facilities, Phosphogypsum Stacks, Underground and Surface Uranium Mines, and the operation and disposal of Uranium Mill Tailings Piles. ne notice also responds to the major public comments on the March 7, 1989 proposed decisions for these categories [54 FR 9612]. EPA is conducting this rulemaking pursuant to a voluntary remand and a schedule issued by the U.S. Court of Appeals for the D.C. Circuit which requires final action by October 31, 1989. In addition EPA is granting a reconsideration of the standards of 40 CFR Part 61 Subpart I, with respect to the issues of 1 duplicative regulation 2 and possible effects on medical treatment. ( ) EFFECTIVE DATE: (Date of publication in FEDERAL REGISTER). Under Section 307 (b) (1) of the CAA, judicial review of decisions under Section 112 is available only by filing a petition for methodologies and quality assurance programs described in paragraph 61.107 (b) or may use the following: Section I (1) Nuclear power reactors may determine their radionuclide emissions in conformance with the Effluent Technical Specifications contained in their Operating License issued by the Nuclear Regulatory Commission. In addition, they may conduct a quality assurance program as described in the Nuclear Regulatory Commission's Regulatory Guide 4.15 dated February 1979. (2) Fuel processing and fabrication plants and uranium hexafloride plants may determine their emissions in conformance with the Nuclear Regulatory Commission's Regulatory Guide 4.16 dated December 1985. In addition, they may conduct a quality assurance program as described in the Nuclear Regulatory Commission's Regulatory Guide 4.15 dated February 1979. (3) Uranium mills may determine their emission in conformance with the Nuclear Regulatory C mission's Regulatory Guide 4.14 dated April 1980. In addition, they may conduct a quality assurance program as described in the Nuclear Regulatory Commission's Regulatory Guide 4.15 dated February 1979. Section 61.108 Exemption from the Reporting and Testing Requirements of 40 CFR 61.10. All facilities designated under this subpart are exempt from the reporting requirements of 40 CFR 61.10. Subpart K - National Emission Standards for Radionuclide 226 EPA has decided that the system discussed for DOE facilities also be used for this source category except that the sources will not use CAP-88 to calculate the doses. Instead they will use the screening models (COMPLY code) described in the BID. 5. Reconsideration of NRC Licensee Category Late in the rulemaking, issues related to the application of the standard in Subpart I to NRC licensees were presented to EPA which raised serious concerns about possible effects of duplicative, and perhaps conflicting, standards on NRC-licensees, including, for example, the use of radioisotope therapies by the National Institute of Health (NIH) and other medical facilities. A The concerns arise from the fact that these licensees would be regulated by both a Clean Air Act standard under Subpart I and an existing NRC standard under 10 CFR Part 20. While the level of health protection achieved under the NRC standard is generally comparable to that required by EPA's rule, the two standards are very different in form, and the means of demonstrating compliance with each standard impose significantly different regulatory requirements. The basic issue is whether these different regulatory requirements will discourage the use of radioisotopes in medical and experimental therapies. In addition, NRC has raised the issue of whether regulation of its licensees under a Clean Air Act standard provides any additional public health benefits. EPA has expressed similar concerns in past proceedings on 69a THE WHITE HOUSE WASHINGTON October 13, 1989 MEMORANDUM FOR JOHN H. SUNUNU FROM: D. ALLAN BROMLEY DAR. SUBJECT: Global Change Activities In case you had not seen it previously, I enclose herewith a copy of a recent item published in Nature concerning the factor of 2 reduction in the temperature change predicted in the U.K. global change models following a first order introduction of cloud phenomena. In my view, this simply highlights the uncertainties in our present predictive capabilities in this area and the difficulties and dangers involved in basing major greenhouse amelioratory programs on current predictions and understanding unless there are other major independent reasons why the individual programs make sense at the present time. I have been concerned by recent rumors to the effect that EPA was moving toward support of CO₂ reduction programs of a substantial nature. I have been unable to make contact directly with Bill Reilly to check this out because we have recently had essentially orthogonal calendars. Recently I had a visit from Mindir Baldur Wagner, the Director of Domestic Programs in the FRG's Chancellor's Office, who is a strong supporter of such programs. He mentioned to me in passing that he was surprised by my position that the currently available science did not support such programs at the present time when EPA, with whom he had visited just previously, had indicated strong support for programs directed toward major CO₂ emission reduction prior to 2000. He wanted to know which was the official U.S. position, and I believe that it is important for us to settle this matter internally SO that we can present a united, coherent posture in our discussions with foreign groups and leaders. Attachment NEWS AND VIEWS CLIMATE CHANGE Wetter clouds dampen global and the fact that 14 models give 14 different answers for the cloud feedback, show that we are far from the goal of accurate greenhouse warming predictions of future climate change. Sensitivity studies such as that reported by Mitchell et al. and comparisons between Tony Slingo models as done by Cess et al. are now the VARIATIONS in cloudiness can signifi- clear that uncertainty in how to formulate bread and butter of climate modelling. cantly affect the Earth's radiation budget clouds represents a formidable obstacle to But at the present rate of progress, it will - the absorbed solar energy and the reliable climate prediction. be several years before reliable predictions thermal energy radiated back to space¹. This underlines the continuing need for of global and regional climate change are This conclusion is supported by various physical parameterizations to be compared available from the models. That under- modelling studies of the 'greenhouse' with results from field studies. This is par- lines the need for comprehensive monitor- effects of increased CO. concentrations ticularly important now that models are ing that is capable of unravelling the In these studies. the CO, forcing induces becoming increasingly complex. Mitchell climate change signal from the noise and changes in the cloud coverage and liquid- et al. argue that the assumptions in their of providing enough data on the state of water content. which alter the radiation model are 'at least qualitatively realistic', the atmosphere, the Earth's radiation budget further and thus "modify the but if climate change simulations are to be budget and clouds for the feedbacks to be original perturbation. On page 132 of this believable. then all parts of a model must determined by observation. Such an issue. Mitchell et al. add a new twist to the be validated quantitatively. and important analysis may well yield the fifteenth story, showing how changes in the relative processes that are ignored must be identi- answer but at least it will have come from amounts of ice-crystal and water-drop fied. Of particular relevance to the cloud the real world and will permit a much clouds substantially reduce the sensitivity problem is the FIRE programme (first needed test of the models. of their model to changes in concentration regional experiment of the international of CO.. Indeed. it is becoming apparent satellite cloud climatology project). both Tony Slingo is in the Climate and Global that uncertainties in the treatment of in its stratocumulus and cirrus field Dynamics Division of the National Center for clouds severely undermine model predic- phases. Several papers are in preparation Atmospheric Research. PO Box 3000. Boulder. Colorado 80307. USA. tion of climate. that highlight the complexity of the meso- Mitchell et al. used various versions of scale dynamical structure of cirrus. so that the UK Meteorological Office atmos- the fall-speed of ice crystals is only part of 1 Ramanathan V et al Science 243 57-63 (1989) pheric general circulation model" coupled the story. It is also interesting that two 2 Schlesinger. M.E. & Mitchell. J.F B. Rev Geophys 25 760-798(1987). to a 50-m ocean mixed layer Replacing cases of highly supercooled liquid-water 3 Schlesinger, M.E. Nature 335 303-304 (1988) the standard cloud prediction scheme altostratus clouds at temperatures around 4 Roeckner E. Nature 335 304 1988). based on relative humidity by a more °C were observed (A.J. Heymsfield 5 Mitchell J.F.B. Senior C.A. & Ingram. W.J. Nature 341 132-134(1989) sophisticated prescription including liquid et al., personal communication). which 6. Slingo. A., Wilderspin. R.C. & Smith. R.N.B. J. geophys water and ice virtually halves the average suggests that the transition from water to Res 94 2281-2301(1989) 7. Wilson, C.A. & Mitchell. J.F.B. J. geophys. Res. 92. equilibrium surface warming due to ice clouds is more subtle than Mitchell et 13315-13343(1987) doubled CO.- from 5.2 K to 2.7 K. They al. assumed for their model. 8. Cess. R.D. et al Science 245. 513-516 (1989). 9 Albrecht. B A., Randall, D.A. & Nicholls S. Bull. Am met argue that this spectacular sensitivity to The sebstantial sensitivity of climate Soc 69 618-626(1988). details of the cloud scheme is caused by models the details of their formulation. 10. Starr. C. Bull. Arr: met. foc 28 119-124(1987) the replacement of ice clouds by water FCOLOGY clouds near the freezing level. In the new cloud scheme. the fall-speed assumed for water drops is much smaller than that for Just proportions in food webs crystals. so that liquid-water clouds can dissipate more slowly than ice clouds. Joel E. Cohen According to Mitchell et al., this leads to the predicted relative increase in water IN FOOD webs of natural communities with new functional patterns. clouds near the freezing level. which con- with varying numbers of species. the McNaughton et al. show that the bio- sequently reduces the amount of solar number of green plants and other species mass. consumption and net secondary energy absorbed in the system (more is that consume no prey in the web basal productivity (NSP) of herbivores are all reflected back into space) and hence gives species) is nearly proportional. on aver- related to the net above-ground primary a smaller warming. When. in addition. age, to the number of species that have productivity (NAP) of a natural habitat by cloud radiative properties are allowed to both predators and prey in the web (inter- simple power laws. Particularly striking is depend on the liquid-water content of mediate species). according to studies that the exponent of the power law that clouds. the surface warming drops still reported over the past dozen years relates NSP to NAP is not significantly further. to only 1.9K. Empirical rules" of that type describe different from 1: to a first approximation. The strong dependence of the magni- structural or anatomical properties of NSP and NAP are directly proportional tude of cloud feedback in this work on the food webs. An important question in In effect. the energy converted into herbi- details of the model parallels results pre- community ecology is whether parallel vores per square metre of surface area sented recently by a large ad hoc group regularities exist in the way in which food per year is. on average. about one- (including Mitchell and mvself) led by webs function On page 142 of this thousandth of the energy that is converted Robert Cess of the State University of issue'. McNaughton et al. report remark- into plants per square metre of surface New York. We compared 14 general able regularities in measures of food web area per year. The ecological energy circulation models and found a three-fold function. Then findings indicate the exist- pyramid has a much larger base than variation in global climate sensitivity. ence of a physiology of food webs that second storey. caused largely by differences in the cloud generalizes across natural communities. This proportionality would be a trivial- feedbacks. The models disagreed not only Their report opens up the distant. but ity if secondary productivity were pas- as to the magnitude but also the sign of the highly attractive. prospect of linking the sively controlled and limited by primary net cloud feedback. For this reason. it is préviously known structural regularities productivity. But this trickle-down view or 104 NATURE VOL 341 : 14 SEPTEMBER 1989 LETTERS 10 NATURE TABLE 2 Newtonian error and signal strength model⁸ cloud cover is a function of relative humidity. A second version of the model was constructed with an explicit cloud- Maximum 1-µm shape error Fifth force water variable for all but deep convective cloud⁹. A balance is Distance Displacement Strain Displacement Strain maintained between cloud water content and water vapour, r f2S f2n f2SA²/a f2hr2/a which is altered by dynamical, convective and boundary-layer (m) (m s⁻²) (s⁻²) (m³ s⁻²) (m²s⁻²) processes. Cloud water content is depleted by precipitation at 2 4 x10⁻¹⁸ 2x10⁻¹⁷ 1.1x10⁻¹³ 3x10⁻¹³ a rate dependent on the phase of the cloud water, which is a 4 1.3x10⁻¹⁹ 3x10⁻¹⁹ 1.4x10⁻¹⁴ 2x10⁻¹⁴ function of the local temperature of the layer. For water cloud 8 4 x10⁻²¹ 5x10⁻²¹ 1.8x10⁻¹⁵ 1.3x10⁻¹⁵ the rate of conversion to precipitation increases as a function of the in-cloud water content and is marginally enhanced in the presence of precipitation from higher layers. The transition from The results detailed here show that it may be feasible to use water cloud to ice cloud occurs between -15 °C and 0 °C as a the asymmetric monopole to test the fifth-force hypothesis, smoothly varying function of temperature. Ice-cloud particles although the experiment is obviously not easy, and practical are assumed to start falling as soon as they form, with a fixed problems remain to be examined in detail. For example, there fall speed of 1 s⁻¹. The rate of precipitation of ice is, on are small elastic distortions in a rotating body as a result of average, an order of magnitude greater than that of water even centrifugal forces. The shape defined by Table 1 is the shape in the presence of precipitation from the layer above. Cloud that must be achieved at the final rotation speed. A numerical radiative properties were prescribed. Note that although the calculation would give the correct initial shape for a given material. Advantages of the experiment are that the experiment revised cloud scheme is more detailed, it is not necessarily more is a null one and one can adjust the shape to find the null, and accurate than the less sophisticated scheme. Our work highlights that only octupole-patterned deformations give rise to error how different parameterization schemes can affect the sensitivity of the climate to CO2. signals as large as in Table 2. Also, the parameters I have chosen (size, distance, tolerance and material) are nominal. There is Two simulations, with CO₂ concentrations of 320 and 640 p.p.m., were performed for each version of the model. The also the possibility that a refinement of this idea, or an incorpor- ation of the mathematical idea into other experimental tech- results shown here are averaged over five years after the simula- niques (such as torsion balances) may prove effective. I note tions reached equilibrium. On replacing the relative-humidity cloud scheme⁸ (henceforth referred to as RH) with the model that the experiment would not depend on any variation of the fifth force with chemical composition, as do many of the recent based on cloud water content9 (CW), the global annual average experiments. surface warming is reduced from 5.2K to 2.7 K. The largest fractional reduction in the warming occurs in higher latitudes (Fig. la) where the large decreases in total cloud cover with Received 8 Mar: accepted 31 July 1989 RH have been replaced by much smaller reductions or slight 1. Sinskv J. A Phys Rev 167, 1145-1151 1968) increases (Fig. 1b). 2. Hyrakawa x & Kuroda. K Phvs Rev. D32, 342-346 1985). With RH, reductions in cloud cover are found throughout the 3. Stubos C. W Nature 338, 301-302 (1989) 4 Stacey E D et al. Rev Mod Phys 59, 157-174 (1987) depth of the mid-latitude troposphere (Fig. 2a), as in earlier 5. Duff G. E D & Naylor. D. Differential Equations of Applied Mathematics 356 (Wiley New York studies³. With CW, the main differences in response occur near 1966) 6. Ward H et a Proc. int. Symp Expi Gravitational Phvs leds Michelson P F Hu E.-L and Pizzella the freezing level Fig. 2b) where, in the warmer doubled-CO₂ G.) 322-327 World Scientific Singapore 1988). 7 Dei Faobro R et ai Phvs Lett. A124, 253-257 (1987) 8 Del Fabbro R et al Phys Lett A132. 237-240 (1987) a 9. Thorne K S in 300 Years of Gravitation leds Hawking, S W & israel. W. 330-458 (Cambridge University Press 1987) ACKNOWLEDGEMENTS thank G Gibbons for discussions about the fifth force J Hough for discussions about detectors and M Hindmarsh for practical help Temperature (K) CO2 and climate: a missing feedback? J. F. B. Mitchell, C. A. Senior & W. J. Ingram Latitude Meteorological Office. London Road. Bracknell RG12 2SZ. UK THE potential of changes in cloud properties to modulate climate perturbations is well known¹.². Changes in cloud amount and cloud height³. cloud radiative properties and cloud condensation nuclei (CCN) have all been recognized as possible sources of climate feedbacks. Here we report results of simulations that indicate that the changes of state of cloud water may provide a substantial negative feedback on climate. The feedback is concen- trated in mid-latitudes and affects both the magnitude and distribu- Fraction 2, tion of the climate change expected from increases in 'greenhouse' gases. Improved measurements and parameterizations of cloud processes are needed to quantify this process. The model is an 11-level atmospheric general-circulation model on a 5°x7.5° (latitude X longitude) horizontal grid Latitude coupled to a 50-m mixed-layer ocean with a prescribed sea- sonally and geographically varying oceanic heat convergence FIG. 1 Zone-averaged equilibrium changes in a. surface temperature and b. to represent heat advection by ocean currents. In the standard fractional cloud cover on doubling CO₂ (five-year means). Solid line. simulation with CW. Dashed line. simulation with RH. 132 NATURE VOL 341 14 SEPTEMBER 1989 LETTERS TO NATURE second simulation, ice cloud which is depleted rapidly by precipitation however, suggesting that any radiative feedback from this type cloud- is replaced by water cloud which is depleted more slowly, so of cloud would be small. lance is that cloud cover increases. This can be seen more clearly in the The lower-cloud increases in the simulations arise from the vapour, height-latitude distribution of the changes in cloud liquid water assumption that under similar conditions ice is removed more ry-layer and cloud ice (Fig. 3). Also shown are the mean 0 °C and -15 °C efficiently from cloud than water. In real water clouds, relatively ition at isotherms in the control simulation. Because of the increases in few droplets become large enough to fall out, as the available ch is a cloud, the enhanced absorption of solar radiation in mid-lati- condensed water is spread over many cloud condensation nuclei r cloud tudes found with RH is greatly reduced when using CW (Fig. 4). (CCN)¹ Very few CCN act as ice nuclei¹, so in ice clouds the inction One can define a climate sensitivity parameter À (=4Q/AT) cloud water is spread over fewer, larger particles, all of which 1 in the where AQ is the change in radiative heating at the tropopause have appreciable fall speeds¹⁴. The microphysics of mixed-phase in from on doubling CO₂ and AT is the equilibrium change in surface clouds are complex and not fully understood. Although our C as a temperature. Assuming¹⁰ AQ=4Wm⁻², À is increased from model does not explicitly represent them it effectively includes articles 0.77 to 1.48 W K⁻¹ on replacing RH by CW. Thus changes their most important aspect, the continual rapid conversion of a fixed in the phase of cloud water provide a strong negative feedback water to ice¹⁵. A more complex representation would certainly is, on on climate, cancelling almost all the previous strong positive change the pattern in Fig. 2 locally, but the vertically integrated er even feedback from cloud in RH". Although our model does not response would probably depend primarily on the overall Cloud allow for this process in deep convective clouds, these have a change from pure ice cloud to pure water cloud. Thus our gh the small areal coverage and a relatively high liquid-water content, assumptions concerning the relative fall-out of ice and water y more are at least qualitatively realistic. hlights As 1 m s⁻¹ may be a large value for ice fall speed, we have sitivity rerun experiment CW using a parameterization of fall speed in : a terms of ice-water content based on observations¹⁴ (experiment 0 and 02 CWH). For typical simulated ice-water contents, this gives fall el. The speeds of 0.2 m s⁻¹ for high ice cloud and 0.7 m s⁻¹ for ice cloud 03 imula- near the freezing level. Cloud changes Fig. 2c) are qualitatively midity 24 similar to Fig. 2b and the global warming is 3.2 K, only slightly model 05 larger than in CW. The similarity between CW and CWH is to verage be expected, given that the depletion rate of ice relative to water 06 largest is large near the freezing level in both experiments. titudes 07 It has recently been suggested that changes in cloud radiative IT with properties may contribute an important feedback to climate 08 slight In a warmer climate, greater cloud water content would increase 09 cloud albedos (a negative feedback) and emittances (a positive out the so 60 5 20 20 40 50 80 feedback). A further experiment was carried out using the earlier Latitude revised version of the model with an additional modification to ir near 0' d-CO₂ b 02 a 03 04 05 35 06 07 08 (3 09 o 3) 80 60 & 20 ) 20 40 60 80 30 50 8 3 0 3 40 60 80 Latitude Latitude 01 c 02 0 1 b 03 04 0 05 0 06- 0 (-) 087 09 0 30 50 40 20 8 20 40 8 Latitude Latitude FIG. 2 Height-latitude cross-section of equilibrium changes in cloud amount FIG. 3 Height-latitude cross-section of equilibrium changes in cloud water on doubling CO₂ The height coordinate is σ (pressure/surface pressure). in CW on doubling CO₂ The height coordinate is σ. Areas of reduction are and b. Areas of reduction are stippled and the contours are every 1%. The dashed stippled. The dashed lines are the 0 and -15 °C contours from the contro ulation lines are the 0 and -15 °C contours from the control simulation. a. Simulation simulation. a. Liquid-water content only. Contours every 4 10⁻⁶ with RH. b. Simulation with CW. C. Simulation with CWH. b. Ice-water content only. Contours every 4 10⁻⁷ kg 1989 NATURE VOL 341 14 SEPTEMBER 1989 133 LETTERS TO NATURE 20 5. Roeckner. E. Nature 335, 304 (1988). 8 6. Schlesinger, M. E. Nature 335, 303-304 (1988). 7. Charlson. R. 1 et at. Nature 334, 418-420 (1988). 16 8. Mitchell. L F. B. & Warnlow. D. A. Nature 330, 238-240 (1987). 9. Smith R. N. B. Q. J R met Soc. (in the press). 14 10. Dickinson, R. E. & Cicerone. R. J. Nature 319, 109-115 (1985). 11. Wilson, C. A. & Mitchell. J. F B. 1 geophys. Res. 92, 13.315-13,343 (1987). 12 12. Pruppacher, H. R. & Klett. J. D. Microphysics of Cloud and Precipitation (Reidel, Dordrecht. 1978 13. Heymsfield. A. J. & Sabin. R. M. 1 atmos. Sci. 46, 2252-2264 (1989). Solar flux (W m 14. Heymsfield. A. J. 1 atmos. Sci. 34, 367-381 (1977). 10 15. Mason. B. J. The Physics of Clouds (Clarendon, Oxford 1957). 8 16. Somerville. R. C. J. & Remer. L A. 1. geophys. Res. 89, 9668-9672 (1984). 17. Liou. K.-N. & Wittman. G. D. L atmos. Scr 36, 1261-1273 (1979). 18. Stephens. G. L. 1 atmos. Sci. 35, 2123-2132 (1978). 6 19. (1988). Somerville. R. C. J. & lacobellis. S. Am. Met Soc. 7th Conf. Ocean-Atmos. interaction 53-5 4 20. Liou, K.-N. & Ou S.-C. Preprints of 10th nt Cloud Phys. Conf. Vol. H. 118-120 (1988). 21. Schlesinger, M. E. & Mitchell. J.F. B. Rev. Geophys 25, 760-798 (1987). 2 22. Hansen, J. E. et al. Geophysical Monographs Series Vol. 29, 130-163 (American Geophysic Union. Washington, DC. 1984). 0 23. Jones. P. D. et al. Nature 338, 790 (1988). 90 80 70 60 50 40 30 20 10 0 10 20 30 40 50 60 70 80 -90 Latitude ACKNOWLEDGEMENTS. We would like to thank R. Smith who devised and wrote the cloud wate scheme used. FIG. 4 Zone-averaged equilibrium change in net solar flux at the top of the atmosphere on doubling CO2 (five-year mean). Solid line, simulation with CW. Dashed line. simulation with RH. Disequilibrium silicate minerah allow the cloud radiative properties to depend on the cloud textures: fractal and water content (scheme CWRP). (Given the similarity between CW and CWH, this experiment was carried out with the CW non-fractal features formulation only.) Analytical fits of the short-wave albedo and transmittance as functions of cloud-water path and solar zenith Anthony D. Fowler*, H. Eugene Stanley angle were made to a published scheme¹ based on observations & Gérard Daccord and theoretical considerations. The long-wave flux emittance was given by (-kq)) where q is the condensed-water * Ottawa-Carleton Geoscience Centre, University of Ottawa. Ottawa. path and K = for water clouds and 0.065 for Ontario. Canada K1N 6N5 ice clouds¹⁸. T Center for Polymer Studies and Department of Physics, On doubling the CO2 concentrations the global annual Boston University, Boston. Massachusetts 02215. USA average equilibrium surface temperature increased by 1.9 K with + Dowell Schlumberger, Z.I. Molina. BP 90. 42003 St Etienne, Cedex 1. France CWRP compared to 2.7K with prescribed cloud radiative properties (CW), indicating a further increase in À to 2.1 Wm⁻² K⁻¹. This negative feedback from changes in cloud IGNEOUS rocks formed from lava flows of the Archaean era radiative properties lies between the very strong negative feed- (>2,700 million years ago) are often found to contain disequili- back suggested by one-dimensional calculations 16,19 and the brium-textured crystals characterized by spherulitic, branching or positive feedback found in a previous study with a low-resol- dendritic morphologies that occur in layers near the flow surface. ution general-circulation model (GCM)⁴⁻⁶. We note that all Well-known examples are the plagioclase spherulites of basalts existing numerical studies assume that the number of CCN and the platy and branching spinnifex-textured olivines and remains constant under climate change. Changes in CCN are a pyroxenes of komatiites Here we present evidence that, over a further possible source of feedback finite range of length scales, some disequilibrium textures are scale The sensitivity of the climate to doubling the CO₂ concentra- invariant. This observation Implies that over this range of length tions that we have found is substantially smaller than the 4-5 K scales their random patterns can be quantitatively characterized found in other recent studies¹⁰.²¹ A significant part of this by a unique number, the fractal dimension³. We also demonstrate reduction in sensitivity is due to the different cloud scheme. If that some textures have a crossover from fractal to non-fractal correct this will have two important consequences. First, the behaviour. It is known that most disequilibrium crystals arise in equilibrium warming expected from the estimated 2 Wm⁻² part from rapid cooling and represent the case where the growth increase in radiative heating at the tropopause since 1860 (ref. rates of the crystals, are large compare to the diffusion rates in will be smaller. Second, the proportion of the equilibrium the silicate melt¹.²,⁴ We therefore formulate a quantitative model for the growth that is based on a variant of diffusion-limited reached will be greater, because the thermal response time of aggregation (DLA)5. the climate system is reduced if climate sensitivity is reduced²². Based on calculations using a simple one-dimensional model Figure 1 shows a section of small disequilibrium crystals, at of the ocean, the expected warming to date, using the climate different magnifications. These form close to the quench/glassy sensitivity found when employing CW, is 0.6 K. This is close to margin of some lava flows⁶, and their outline remains the same the observed warming since the beginning of the century (0.5 K; as the microscope objective power is increased Similar remarks ref. 23). The record of observations shows considerable variabil- can be made about textures on other length scales, such as the ity on interannual and interdecadal timescales, however, includ- much larger branching pyroxene crystal of Fig. 2a. ing a period of cooling during the 1950s and 1960s, so that it The concepts and techniques of fractal geometry have proven is not possible to attribute the 0.5 K rise unambiguously to the useful in understanding other random morphologies, in part effect of increases in trace gases. because a fractal object is characterized quantitatively by a number, the fractal dimension d,, that relates the increase in mass M of the object to its characteristic length scale L, M = L1 Received 14 June: accepted 14 August 1989 (ref. 7) 1. Manabe. S. & Wetherald. R. T J. atmos Sci, 24. 241-259 (1967) To determine d, we digitized photographs of the textures using 2. Schneider, S. H. J. atmos Sci. 29. 1413-1422 (1972). a video camera with a grid of 65,536 pixels. First we randomly 3. Wetherald. R. T & Manabe S 1 atmos. Sci. 45. 1397-1415 (1988). 4 Roeckner. E. et al Nature 329. 138-140 (1987) chose any pixel belonging to the digitized texture. About this 'local origin' we constructed a sequence of concentric shells of 134 NATURE VOL 341 14 SEPTEMBER 1989 DAB-FYI Dr. Bromley: 10/13/89 OPINION Based upon my listening very hard to both our domestic and international communities (scientific and policy) over the past weeks, I think it is very important for both you and the President to come across as strong supporters for positive and agressive steps to protect the global environment. Of course, we must proceed with a realistic and careful view of the costs/impacts across the board (industry, etc) but we must appear to be out front environmentally. Important: There is a risk here that you, OSTP, and the President may appear to be foot-dragging on the issue, when, in fact, we are attempting to shape a careful, prudent, and coordinated US Gov't approach and policy. I will be meeting with DPC folks this afternoon matter. (Also, on the matter of climate Models) on the issue but we should talk soon on the entire N. Sensible article by Slingo attached on climate models- d think we should use caution in the use or reference to these models. There is no question now that changes will occur The modela present different scenarion of change. Most agree, however, that we need to respond- we just need to determine the most sensible way to respond as a government NEWS AND VIEWS CLIMATE CHANGE Wetter clouds dampen global and the fact that 14 models give 14 different answers for the cloud feedback, show that we are far from the goal of accurate greenhouse warming predictions of future climate change. Sensitivity studies such as that reported by Tony Slingo Mitchell et al. and comparisons between models as done by Cess et al. are now the VARIATIONS in cloudiness can signifi- clear that uncertainty in how to formulate bread and butter of climate modelling. cantly affect the Earth's radiation budget clouds represents a formidable obstacle to But at the present rate of progress, it will - the absorbed solar energy and the reliable climate prediction. be several years before reliable predictions thermal energy radiated back to space¹. This underlines the continuing need for of global and regional climate change are This conclusion is supported by various physical parameterizations to be compared available from the models. That under- modelling studies of the 'greenhouse' with results from field studies. This is par- lines the need for comprehensive monitor- effects of increased CO₂ concentrations². ticularly important now that models are ing that is capable of unravelling the In these studies, the CO, forcing induces becoming increasingly complex. Mitchell climate change signal from the noise and changes in the cloud coverage and liquid- et al. argue that the assumptions in their of providing enough data on the state of water content, which alter the radiation model are 'at least qualitatively realistic', the atmosphere, the Earth's radiation budget further and thus modify the but if climate change simulations are to be budget and clouds for the feedbacks to be original perturbation. On page 132 of this believable, then all parts of a model must determined by observation. Such an issue', Mitchell et al. add a new twist to the be validated quantitatively, and important analysis may well yield the fifteenth story, showing how changes in the relative processes that are ignored must be identi- answer but at least it will have come from amounts of ice-crystal and water-drop fied. Of particular relevance to the cloud the real world and will permit a much clouds substantially reduce the sensitivity problem is the FIRE programme (first needed test of the models. of their model to changes in concentration regional experiment of the international of CO2. Indeed. it is becoming apparent satellite cloud climatology project), both Tony Slingo is in the Climate and Global that uncertainties in the treatment of in its stratocumulus and cirrus¹ field Dynamics Division of the National Center for clouds severely undermine model predic- phases. Several papers are in preparation Atmospheric Research, PO Box 3000, Boulder, tion of climate. that highlight the complexity of the meso- Colorado 80307, USA. Mitchell et al. used various versions of scale dynamical structure of cirrus, so that the UK Meteorological Office atmos- the fall-speed of ice crystals is only part of 1. Ramanathan, V. et al. Science 243. 57-63 (1989). pheric general circulation model coupled the story. It is also interesting that two 2. Schlesinger, M.E. & Mitchell, J.F.B. Rev. Geophys. 25. to a 50-m ocean mixed layer'. Replacing cases of highly supercooled liquid-water 760-798 (1987). 3. Schlesinger, M.E. Nature 335. 303-304 (1988). the standard cloud prediction scheme altostratus clouds at temperatures around 4. Roeckner. E. Nature 335. 304 (1988). based on relative humidity by a more -30 °C were observed (A.J. Heymsfield 5. Mitchell, J.F.B., Senior, C.A. & Ingram, W.J. Nature 341. 132-134 (1989). sophisticated prescription including liquid et al., personal communication), which 6. Slingo, A., Wilderspin, R.C. & Smith, R.N.B. J. geophys. water and ice virtually halves the average suggests that the transition from water to Res. 94. 2281-2301 (1989). equilibrium surface warming due to ice clouds is more subtle than Mitchell et 7. Wilson, C.A. & Mitchell, J.F.B. J. geophys. Res. 92. 13315-13343 (1987). doubled CO, from 5.2 K to 2.7 K. They al. assumed for their model. 8. Cess. R.D. et al. Science 245, 513-516 (1989). argue that this spectacular sensitivity to The substantial sensitivity of climate 9. Albrecht, B.A., Randall, D.A. & Nicholls. S. Bull. Am. met. Soc. 69, 618-626 (1988). details of the cloud scheme is caused by models to the details of their formulation, 10. Starr, D.O.'C. Bull. Am. met. Soc. 68. 119-124 (1987). the replacement of ice clouds by water ECOLOGY clouds near the freezing level. In the new cloud scheme, the fall-speed assumed for water drops is much smaller than that for Just proportions in food webs ice crystals, so that liquid-water clouds can dissipate more slowly than ice clouds. Joel E. Cohen According to Mitchell et al., this leads to the predicted relative increase in water IN FOOD webs of natural communities with new functional patterns. clouds near the freezing level, which con- with varying numbers of species, the McNaughton et al. show that the bio- sequently reduces the amount of solar number of green plants and other species mass, consumption and net secondary energy absorbed in the system (more is that consume no prey in the web (basal productivity (NSP) of herbivores are all reflected back into space) and hence gives species) is nearly proportional, on aver- related to the net above-ground primary a smaller warming. When, in addition, age, to the number of species that have productivity (NAP) of a natural habitat by cloud radiative properties are allowed to both predators and prey in the web (inter- simple power laws. Particularly striking is depend on the liquid-water content of mediate species), according to studies that the exponent of the power law that clouds, the surface warming drops still reported over the past dozen years relates NSP to NAP is not significantly further. to only 1.9 K. Empirical rules⁵.⁶ of that type describe different from 1: to a first approximation. The strong dependence of the magni- structural or anatomical properties of NSP and NAP are directly proportional. tude of cloud feedback in this work on the food webs. An important question in In effect, the energy converted into herbi- details of the model parallels results pre- community ecology is whether parallel vores per square metre of surface area sented recently* by a large ad hoc group regularities exist in the way in which food per year is, on average, about one- (including Mitchell and myself) led by webs function⁷ On page 142 of this thousandth of the energy that is converted Robert Cess of the State University of issue, McNaughton et al. report remark- into plants per square metre of surface New York. We compared 14 general able regularities in measures of food web area per year. The ecological energy circulation models and found a three-fold function. Their findings indicate the exist- pyramid has a much larger base than variation in global climate sensitivity, ence of a physiology of food webs that second storey. caused largely by differences in the cloud generalizes across natural communities. This proportionality would be a trivial- feedbacks. The models disagreed not only Their report opens up the distant, but ity if secondary productivity were pas- as to the magnitude but also the sign of the highly attractive, prospect of linking the sively controlled and limited by primary net cloud feedback. For this reason, it is préviously known structural regularities productivity. But this trickle-down view of 104 NATURE VOL 341 14 SEPTEMBER 1989 LETTERS TO NATURE TABLE 2 Newtonian error and signal strength model⁸ cloud cover is a function of relative humidity. A second version of the model was constructed with an explicit cloud- Maximum 1-µm shape error Fifth force water variable for all but deep convective cloud⁹. A balance is Distance Displacement Strain Displacement Strain maintained between cloud water content and water vapour, r f2S f2h f²SX²/α f2hx2/α which is altered by dynamical, convective and boundary-layer (m) (ms⁻²) (s⁻²) (m³ s⁻²) (m²s⁻²) processes. Cloud water content is depleted by precipitation at 2 4 x10⁻¹⁸ 2x10⁻¹⁷ 1.1x10⁻¹³ 3x10⁻¹³ a rate dependent on the phase of the cloud water, which is a 4 1.3x10⁻¹⁹ 3x10⁻¹⁹ 1.4x10⁻¹⁴ 2x10⁻¹⁴ function of the local temperature of the layer. For water cloud 8 4 x10⁻²¹ 5x10⁻²¹ 1.8x10⁻¹⁵ 1.3x10⁻¹⁵ the rate of conversion to precipitation increases as a function of the in-cloud water content and is marginally enhanced in the presence of precipitation from higher layers. The transition from The results detailed here show that it may be feasible to use water cloud to ice cloud occurs between -15 °C and 0 °C as a the asymmetric monopole to test the fifth-force hypothesis, smoothly varying function of temperature. Ice-cloud particles although the experiment is obviously not easy, and practical are assumed to start falling as soon as they form, with a fixed problems remain to be examined in detail. For example, there fall speed of 1 m s⁻¹. The rate of precipitation of ice is, on are small elastic distortions in a rotating body as a result of average, an order of magnitude greater than that of water even centrifugal forces. The shape defined by Table 1 is the shape in the presence of precipitation from the layer above. Cloud that must be achieved at the final rotation speed. A numerical radiative properties were prescribed. Note that although the calculation would give the correct initial shape for a given revised cloud scheme is more detailed, it is not necessarily more material. Advantages of the experiment are that the experiment is a null one and one can adjust the shape to find the null, and accurate than the less sophisticated scheme. Our work highlights that only octupole-patterned deformations give rise to error how different parameterization schemes can affect the sensitivity of the climate to CO2. signals as large as in Table 2. Also, the parameters I have chosen (size, distance, tolerance and material) are nominal. There is Two simulations, with CO₂ concentrations of 320 and 640 p.p.m., were performed for each version of the model. The also the possibility that a refinement of this idea, or an incorpor- ation of the mathematical idea into other experimental tech- results shown here are averaged over five years after the simula- niques (such as torsion balances) may prove effective. I note tions reached equilibrium. On replacing the relative-humidity cloud scheme⁸ (henceforth referred to as RH) with the model that the experiment would not depend on any variation of the fifth force with chemical composition, as do many of the recent based on cloud water content9 (CW), the global annual average experiments. surface warming is reduced from 5.2K to 2.7 K. The largest fractional reduction in the warming occurs in higher latitudes (Fig. 1a) where the large decreases in total cloud cover with Received 8 May; accepted 31 July 1989. RH have been replaced by much smaller reductions or slight 1. Sinsky, J. A. Phys. Rev. 167, 1145-1151 (1968). increases (Fig. 1b). 2. Hyrakawa. K. & Kuroda, K. Phys. Rev. D32, 342-346 (1985). With RH, reductions in cloud cover are found throughout the 3. Stubbs, C. W. Nature 338, 301-302 (1989). 4. Stacey. F.D. et al. Rev. Mod. Phys. 59, 157-174 (1987). depth of the mid-latitude troposphere (Fig. 2a), as in earlier 5. Duff, G. F. D. & Naylor, D. Differential Equations of Applied Mathematics 356 (Wiley, New York, studies³. With CW, the main differences in response occur near 1966). 6. Ward. H. et al. Proc. Int. Symp. Expl. Gravitational Phys. (eds Michelson, P.F., Hu. E.-L. and Pizzella, the freezing level (Fig. 2b) where, in the warmer doubled-CO₂ G.) 322-327 (World Scientific, Singapore, 1988). 7. Del Fabbro. R. et al. Phys. Lett. A124, 253-257 (1987). 90 8. Del Fabbro. R. et al. Phys. Lett. A132, 237-240 (1987). a 9. Thorne, K. S. in 300 Years of Gravitation (eds Hawking, S. W. & Israel, W.), 330-458 (Cambridge 80 University Press. 1987). 70 ACKNOWLEDGEMENTS I thank G. Gibbons for discussions about the fifth force, J. Hough for discussions 60 about gravity-wave detectors and M. Hindmarsh for practical help. Temperature (K) 50 40 CO2 and climate: a missing 30 20 feedback? 10 00 J. F. B. Mitchell, C. A. Senior & W. J. Ingram 06 80 70 60 50 40 30 20 10 0 10 20 30 40 50 60 70 80 90 Latitude Meteorological Office, London Road, Bracknell RG12 2SZ, UK 40 THE potential of changes in cloud properties to modulate climate b 30 perturbations is well known¹,². Changes in cloud amount and cloud 20 height³, cloud radiative properties⁴⁶ and cloud condensation 10 nuclei⁷ (CCN) have all been recognized as possible sources of 00 climate feedbacks. Here we report results of simulations that 10 indicate that the changes of state of cloud water may provide a trated in mid-latitudes and affects both the magnitude and distribu- Fraction 2) 20 substantial negative feedback on climate. The feedback is concen- 30 40 tion of the climate change expected from increases in 'greenhouse' 50 gases. Improved measurements and parameterizations of cloud 60 :0 processes are needed to quantify this process. The model is an 11-level atmospheric general-circulation 80 90 80 70 60 50 40 30 20 10 0 - 20 30 40 5 60 70 80 90 model on a 5°x7.5° (latitude longitude) horizontal grid Latitude coupled to a 50-m mixed-layer ocean with a prescribed sea- sonally and geographically varying oceanic heat convergence FIG. 1 Zone-averaged equilibrium changes in a, surface temperature and b, to represent heat advection by ocean currents⁸. In the standard fractional cloud cover on doubling CO₂ (five-year means). Solid line, simulation with CW. Dashed line, simulation with RH. 132 NATURE VOL 341 14 SEPTEMBER 1989 LETTERS TO NATURE second simulation, ice cloud which is depleted rapidly by precipitation however, suggesting that any radiative feedback from this type cloud- is replaced by water cloud which is depleted more slowly, so of cloud would be small. lance is that cloud cover increases. This can be seen more clearly in the The lower-cloud increases in the simulations arise from the vapour, height-latitude distribution of the changes in cloud liquid water assumption that under similar conditions ice is removed more ry-layer and cloud ice (Fig. 3). Also shown are the mean 0 °C and 15 °C efficiently from cloud than water. In real water clouds, relatively ation at isotherms in the control simulation. Because of the increases in few droplets become large enough to fall out, as the available ich is a cloud, the enhanced absorption of solar radiation in mid-lati- condensed water is spread over many cloud condensation nuclei :r cloud tudes found with RH is greatly reduced when using CW (Fig. 4). (CCN)¹² Very few CCN act as ice nuclei¹³, so in ice clouds the unction One can define a climate sensitivity parameter \ (=QQ/AT) cloud water is spread over fewer, larger particles, all of which d in the where AQ is the change in radiative heating at the tropopause have appreciable fall speeds¹⁴. The microphysics of mixed-phase on from on doubling CO₂ and T is the equilibrium change in surface clouds are complex and not fully understood. Although our °C as a temperature. Assuming¹⁰ = W \ is increased from model does not explicitly represent them it effectively includes articles 0.77 to 1.48 W K⁻¹ on replacing RH by CW. Thus changes their most important aspect, the continual rapid conversion of a fixed in the phase of cloud water provide a strong negative feedback water to ice¹⁵. A more complex representation would certainly is, on on climate, cancelling almost all the previous strong positive change the pattern in Fig. 2 locally, but the vertically integrated er even feedback from cloud in RH¹¹. Although our model does not response would probably depend primarily on the overall Cloud allow for this process in deep convective clouds, these have a change from pure ice cloud to pure water cloud. Thus our igh the small areal coverage and a relatively high liquid-water content, assumptions concerning the relative fall-out of ice and water y more are at least qualitatively realistic. hlights As 1 m may be a large value for ice fall speed, we have sitivity rerun experiment CW using a parameterization of fall speed in 01 a terms of ice-water content based on observations (experiment 20 and 02 CWH). For typical simulated ice-water contents, this gives fall el. The speeds of 0.2 m s⁻¹ for high ice cloud and 0.7 m s⁻¹ for ice cloud 03 simula- near the freezing level. Cloud changes (Fig. 2c) are qualitatively 2 midity 04 15 similar to Fig. 2b and the global warming is 3.2 K, only slightly model 0 0.5 larger than in CW. The similarity between CW and CWH is to iverage σ -1 be expected, given that the depletion rate of ice relative to water ? 06 0 largest 2 is large near the freezing level in both experiments. titudes 0.7 2 It has recently been suggested that changes in cloud radiative er with properties may contribute an important feedback to climate⁴,⁵,¹⁶. 0.8 Γ slight 0 0 In a warmer climate, greater cloud water content would increase 0.9 0 cloud albedos (a negative feedback) and emittances (a positive out the 80 60 40 20 0 -20 -40 -60 80 feedback). A further experiment was carried out using the earlier Latitude revised version of the model with an additional modification to ur near 0.1 ed-CO2 b 0.2 a 0.1 0.3 0.2 0 -2 0.4 -1 0.3 0 0.5 04 15 b 0 σ 0.5 0.6 0.6 0.7 0 07 -1 -1 0.8 (3 0.8 0 0.9 0 3) 09 80 60 40 20 0 -20 -40 -60 -80 80 60 40 20 0 -20 -40 -60 -80 Latitude Latitude 0.1 c 2 3 0.2 0 0 01 b 0.3 I 0.2 0 2 0.4 0 -2 03 0.5 0 0.4 15 b σ 0.5 0.6 0 0 0 0.6 0.7 2 0 07 (w) 0.8 1 0.8 0.9 2 0.9 (10) on 80 60 40 20 0 -20 -40 60 80 80 60 40 20 0 20 -40 -60 -80 Latitude Latitude FIG. 2 Height-latitude cross-section of equilibrium changes in cloud amount FIG. 3 Height-latitude cross-section of equilibrium changes in cloud water on doubling CO2. The height coordinate is σ (pressure/surface pressure). in CW on doubling CO2. The height coordinate is σ. Areas of reduction are and b. Areas of reduction are stippled and the contours are every 1%. The dashed stippled. The dashed lines are the 0 and -15 °C contours from the control ulation lines are the 0 and -15 °C contours from the control simulation. a, Simulation simulation. a, Liquid-water content only. Contours every 4 kgkg⁻¹. with RH. b, Simulation with CW. C, Simulation with CWH. b, Ice-water content only. Contours every 4 x10⁻⁷ kgkg⁻¹ 1989 NATURE VOL 341 14 SEPTEMBER 1989 133 LETTERS TO NATURE 20 5. Roeckner, E. Nature 335, 304 (1988). 18 6. Schlesinger, M. E. Nature 335, 303-304 (1988). 7. Charlson, R. J. et al. Nature 334, 418-420 (1988). 16 8. Mitchell, J.F. B. & Warrilow, D. A. Nature 330, 238-240 (1987). 9. Smith, R. N. B. Q. JI R. met. Soc. (in the press). 14 10. Dickinson, R. E. & Cicerone. R. J. Nature 319, 109-115 (1985). 11. Wilson, C. A. & Mitchell, J. F. B. J. geophys. Res. 92, 13,315-13,343 (1987). 12 12. Pruppacher, H. R. & Klett, J. D. Microphysics of Cloud and Precipitation. (Reidel, Dordrecht, 1978 13. Heymsfield, A. J. & Sabin, R. M. 1 atmos. Sci. 46, 2252-2264 (1989). Solar flux (W m 10 14. Heymsfield, A. J. 1 atmos. Sci. 34, 367-381 (1977). 15. Mason, B. J. The Physics of Clouds (Clarendon, Oxford, 1957). 8 16. Somerville, R. C. J. & Remer, L. A. J. geophys. Res. 89, 9668-9672 (1984). 17. Liou, K.-N. & Wittman, G. D. J. atmos. Sci. 36, 1261-1273 (1979). 6 18. Stephens, G. L. J. atmos. Sci. 35, 2123-2132 (1978). 19. (1988). Somerville, R. C. J. & lacobellis, S. Am. Met. Soc. 7th Conf. Ocean-Atmos. Interaction 53-5. 4 20. Liou, K.-N. & Ou S.-C. Preprints of 10th Int. Cloud Phys. Conf. Vol. II, 118-120 (1988). 2 21. Schlesinger, M. E. & Mitchell, J. F. B. Rev. Geophys. 25, 760-798 (1987). 22. Hansen, J. E. et al. Geophysical Monographs Series Vol. 29, 130-163 (American Geophysica Union, Washington, DC, 1984). 0 23. Jones, P. D. et al. Nature 338, 790 (1988). 90 80 70 60 50 40 30 20 10 0 -10 -20 -30 -40 -50 -60 70 80 -90 Latitude ACKNOWLEDGEMENTS. We would like to thank R. Smith who devised and wrote the cloud wate scheme used. FIG. 4 Zone-averaged equilibrium change in net solar flux at the top of the atmosphere on doubling CO₂ (five-year mean). Solid line, simulation with CW. Dashed line, simulation with RH. Disequilibrium silicate mineral allow the cloud radiative properties to depend on the cloud textures: fractal and water content (scheme CWRP). (Given the similarity between CW and CWH, this experiment was carried out with the CW non-fractal features formulation only.) Analytical fits of the short-wave albedo and transmittance as functions of cloud-water path and solar zenith Anthony D. Fowler*, H. Eugene Stanley* angle were made to a published scheme¹¹ based on observations & Gérard Daccord and theoretical considerations. The long-wave flux emittance was given by (-кq)) where q is the condensed-water * Ottawa-Carleton Geoscience Centre, University of Ottawa, Ottawa, path and K = 0.13 for water clouds and 0.065 m² for Ontario, Canada K1N 6N5 ice clouds¹⁸. t Center for Polymer Studies and Department of Physics, On doubling the CO₂ concentrations the global annual Boston University, Boston, Massachusetts 02215, USA average equilibrium surface temperature increased by 1.9 K with + Dowell Schlumberger, Z.I. Molina, BP 90, 42003 St Etienne, Cedex 1, France CWRP compared to 2.7 K with prescribed cloud radiative properties (CW), indicating a further increase in 1 to 2.1 W K⁻¹. This negative feedback from changes in cloud IGNEOUS rocks formed from lava flows of the Archaean era radiative properties lies between the very strong negative feed- (>2,700 million years ago) are often found to contain disequili- back suggested by one-dimensional calculations and the brium-textured crystals characterized by spherulitic, branching or positive feedback found in a previous study with a low-resol- dendritic morphologies that occur in layers near the flow surface. ution general-circulation model (GCM)⁴⁻⁶ We note that all Well-known examples are the plagioclase spherulites of basalts existing numerical studies assume that the number of CCN and the platy and branching spinnifex-textured olivines and remains constant under climate change. Changes in CCN are a pyroxenes of komatiites¹, Here we present evidence that, over a further possible source of feedback⁷,²⁰ finite range of length scales, some disequilibrium textures are scale The sensitivity of the climate to doubling the CO₂ concentra- invariant. This observation implies that over this range of length tions that we have found is substantially smaller than the 4-5 K scales their random patterns can be quantitatively characterized found in other recent studies¹⁰,²¹. A significant part of this by a unique number, the fractal dimension³. We also demonstrate reduction in sensitivity is due to the different cloud scheme. If that some textures have a crossover from fractal to non-fractal correct this will have two important consequences. First, the behaviour. It is known that most disequilibrium crystals arise in equilibrium warming expected from the estimated 2 Wm⁻² part from rapid cooling and represent the case where the growth increase in radiative heating at the tropopause since 1860 (ref. 9) rates of the crystals/are large compare to the diffusion rates in will be smaller. Second, the proportion of the equilibrium the silicate melt We therefore formulate a quantitative model reached will be greater, because the thermal response time of for the growth that is based on a variant of diffusion-limited the climate system is reduced if climate sensitivity is reduced²². aggregation (DLA)5. Based on calculations using a simple one-dimensional model Figure 1 shows a section of small disequilibrium crystals, at of the ocean, the expected warming to date, using the climate different magnifications. These form close to the quench/glassy sensitivity found when employing CW, is 0.6 K. This is close to margin of some lava flows⁶, and their outline remains the same the observed warming since the beginning of the century (0.5 K; as the microscope objective power is increased. Similar remarks ref. 23). The record of observations shows considerable variabil- can be made about textures on other length scales, such as the ity on interannual and interdecadal timescales, however, includ- much larger branching pyroxene crystal of Fig. 2a. ing a period of cooling during the 1950s and 1960s, so that it The concepts and techniques of fractal geometry3 have proven is not possible to attribute the 0.5 K rise unambiguously to the useful in understanding other random morphologies, in part effect of increases in trace gases. because a fractal object is characterized quantitatively by a number, the fractal dimension df, that relates the increase in mass M/of the object to its characteristic length scale L, M ≈ Received 14 June; accepted 14 August 1989. (ref. 7) 1. Manabe, S. & Wetherald. R. T. J. atmos. Sci. 24, 241-259 (1967). To determine d{ we digitized photographs of the textures using 2. Schneider, S. H. J. atmos. Sci. 29, 1413-1422 (1972). 3. Wetherald, R. T. & Manabe. S. J. atmos. Sci. 45, 1397-1415 (1988). a video camera with a grid of 65,536 pixels. First we randomly 4. Roeckner, E. et al. Nature 329, 138-140 (1987). chose any pixel belonging to the digitized texture. About this 'local origin' we constructed a sequence of concentric shells of 134 NATURE VOL 341 14 SEPTEMBER 1989 THE WHITE HOUSE WASHINGTON September 20, 1989 MEMORANDUM FOR JOHN SUNUNU ASSISTANT TO THE Out FOR CHIEF OF STAFF TO PRESIDENT FROM: D. ALLAN BROMLEY SCIENCE AND TECHNOLOGY SUBJECT: GLOBAL ENVIRONMENTAL CHANGE Enclosed herewith is a memorandum for the President on this topic in which I make the suggestion for a meeting of senior scientific representatives that I discussed very briefly with you on Tuesday. Immediately after our discussion I met with the delegation from the British Houses of Commons and of Lords. During the discussion I floated the idea of this meeting and, at least in this group, met with a very enthusiastic response. I recognize fully that there may be many other factors that will decide how best the President should follow up on what has come to be considered, in many quarters, his promise to host a Summit on the global environment. My goals are a) to insure that the Summit, when it occurs, can show concrete results and b) that either by design or inadvertence it not be to closely focussed on global warming as some would like it. THE WHITE HOUSE WASHINGTON December 1, 1989 Dear Bill: Many thanks for your note of November 8 and your "Sixteen Theses on the Greenhouse Effect." You quite correctly assume that I am in the middle of the global warming problem, having been asked by the President to chair the Domestic Policy Council Working Group on that subject, charged with developing the formal U.S. government policy on the matter. As you are also quite aware, there has been a wide divergence of opinion, and the task of pulling this together into a coherent policy is anything but a simple one. Your input is particularly valuable, because I have asked Mike Boskin and his folk in the Council of Economic Advisers to take on the task of quantifying, in an economic sense, the impact of postulated scenarios for global warming as the basis for the development of some reasonable policies. In parallel with that, I have also asked the Department of the Interior to coordinate the collection of input from the private industrial sector, a group that has substantial experience, expertise and data in the area but which has been remarkably absent from the discussion thus far, and I have also asked the Justice Department, together with the State Department, to take a look at the kind of framework agreement that we might eventually be prepared to sign. My impression has been that all too frequently in the past we have tended to get shafted in international agreements because we have not done adequate homework before the fact and during the actual negotiations have frequently tended to be nice guys, to our eventual cost. In parallel with these activities, we are meeting with groups of scientists actively working in the field, with groups of economists who have been looking at the area, because there is an impressive divergence of opinion within the economic community and, finally, with groups of spokespersons for the most visible environmental groups. My intent is that with these activities proceeding in parallel with the United Nations activities, under the Intergovernmental Panel on Climate Change, we should be prepared by the latter part of 1990 to discuss the sort of quantitative schedules and possible stabilization and reduction of greenhouse emissions that an amazing fraction of the seventy nations represented at the recent Noordwijk conference were prepared to commit themselves to in the absence of any clear understanding of either the technology required or the economic consequences of their commitments. As you well know from your own experience in Washington, there are a great many things that one does not discover prior to arriving on the scene, but at least I am learning that one can be beaten about head and shoulders for all manner of things beyond global warming, with technology policy being a marvelous followup. I am enclosing herewith for your possible interest a set of conclusions that I jotted down on the plane on the way back from the Noordwijk conference early in November that I have subsequently passed on to the President. Although the press has been making much of the fact that Bill Reilly and I are in opposing camps on these global warming questions, we in fact have been working rather closely together and, as a good Class of '64 Yalie, I find him to be a very able and persuasive colleague. With all best wishes, Sincerely yours, I llan D. Allan Bromley Assistant to the President for Science and Technology Enclosure Professor William D. Nordhaus Department of Economics Yale University P.O. Box 1972 Yale Station New Haven, Connecticut 06520-1972 OF HEALTH& SECURITY HUMAN THE SECRETARY OF HEALTH AND HUMAN SERVICES WASHINGTON, D.C. 20201 USA OCT 16 1989 Mr. D. Allan Bromley Assistant to the President for Science and Technology The White House Washington, D.C. Dear Mr. Bromley: Thank you for your letter endorsing Dr. Bernadine Healy for the position of Director, National Institutes of Health here in the Department of Health and Human Services. The need to attract highly-qualified individuals here in the Department is great. Dr. Healy's resume is quite impressive. Please be certain that she will be given careful and thorough consideration as I review applications for this position. Again, thank you for providing me with the name of a candidate that you feel would be an asset to the Department. With warm regards. Sincerely, Louis W.Aulliran Louis W. Sullivan, M.D. Secretary "CORRESPONDENCE TRACKING" TYPE: Action Item DOCUMENT NUMBER: 8920380 FROM: WILLIAM D. NORDHAUS YALE UNIVERSITY TO: BROMLEY DATE OF CORRESPONDENCE: 11/08/89 SUBJECT: ENCLOSING A COPY OF A SUMMARY DONE FOR THE COUNCIL ON ECONOMIC ADVISORS FOR YOUR INFORMATION. ASSIGNED TO: D. Allan Bromley ACTION REQUIRED: ACKNOWLEDGE SENDER'S DUE DATE: OSTP DUE DATE: 12/04/89 DATE COMPLETED: COPIES TO: Nancy Maynard REMARKS: DATE RECEIVED: 11/15/89 FILE: NEOB Yale University Department of Economics Campus address: P.O. Box 1972 Yale Station 28 Hillhouse Avenue New Haven, Connecticut 06520-1972 Dr. D. Allan Bromley President's Science Adviser Executive Office Building Washington, D. C. November 8, 1989 Dear Allan: You new duties undoubtedly are involving you in the hot issue of global warming. In this regard, I thought you might be interested in a summary that I recently prepared for your colleagues in the Council of Economic Advisers. I trust you are well. Things are temporarily calm here. Sincerely yours, Bair William D. Nordhaus THE WHITE HOUSE WASHINGTON September 20, 1989 MEMORANDUM FOR THE PRESIDENT sue FROM: D. ALLAN BROMLEY SUBJECT: HEAD OF STATE MEETING ON THE GLOBAL ENVIRONMENT I know that you are currently considering how best to follow-up on your discussions at, and before, the Paris Economic Summit regarding a Head-of-State meeting focused on the global environment. I recognize that you will necessarily weigh many factors in reaching your decision but want, in this memorandum, to make a few comments and a specific suggestion from my science and technology vantage point. First, I believe that it would be a mistake to plan any such Head-of-State meeting too closely in time to the scheduled February 1990, IPCC meeting to be held here in Washington because the latter is rather focussed on global warming and this is only a part, albeit a highly public part, of the more general global environmental change question. Too close a coupling would, in my opinion, give undue emphasis to the global warming problem to the exclusion of others such as ocean pollution, biodiversity, and a whole host of other topics. Second, I would argue that it would be important that the necessary preparatory work be done so that you would be in a position at the Head-of-State meeting to sign, with your fellow Heads of State, an agreement having very solid content. To that end, I would propose - and have discussed very briefly with Governor Sununu - the possibility that in, say, April 1990, I host, here in Washington, a meeting of the Science Ministers or their equivalent from the seven nations involved in the Economic Summit in which we might try to agree upon a set of environmental change issues of international importance (including global warming, of course) and focus on the state of our current scientific knowledge of the phenomena underlying them. Having identified at least some of the most important gaps in such knowledge, we could then at least attempt to evolve a coherent, integrated plan, involving the scientific and technological communities of these seven nations, to address these gaps. If we were successful, then such a plan might provide an appropriate environmental centerpiece upon which the Heads of State could formally agree and to which they might be prepared to commit their respective countries for action. I make this suggestion, Mr. President, for the additional reason that it would allow you to maintain the strong leadership role that this country has earned and that you so effectively demonstrated at Paris. The possibility of including a broader spectrum of nations is one that I have rejected, not because they do not have essential contributions to make but rather to keep this initial discussion within manageable bounds. To the extent that we are successful initially we certainly would wish to spread our net rather early to include much broader representation. I would welcome your guidance and comments.