APPENDIX

PREPARED STATEMENT OF HON. JOHN F. KERRY, U.S. SENATOR
FROM MASSACHUSSETTS

I want to thank Chairman McCain for holding today's hearing. As I have expressed to the Committee before, I believe that addressing the threat of climate change is one of the great challenges before the nation and the world. It certainly deserves the attention of this Committee.

Our topic today is the Intergovernmental Panel on Climate Change's Third Assessment Report. I want to take just a moment to discuss some of the history of the IPCC.

The Panel was created in 1988 to serve as an independent advisor to world leaders in assessing the scientific, technical and socio-economic information relevant for the understanding of the risk of human-induced climate change. Here in Washington that translated into studying the "scientific uncertainties" of global warming. In an April 1989 appropriations letter to Congress, President Bush wrote, "Significant uncertainties remain about the magnitude, timing, and regional impacts of global climate change. During Fiscal Year 1988, the United States has made major contributions to international plans to reduce those uncertainties." Among the contributions the President noted was the Intergovernmental Panel on Climate Change, which, he said, "launched its multilateral effort in November 1988 with U.S. participation and support."

In a speech to the IPCC in February 1990, President Bush concluded that "human activities are changing the atmosphere in unexpected and unprecedented ways." And that, "the United States will continue its efforts to improve our understanding of climate change, to seek hard data, accurate models and new ways to improve the science and determine how best to meet these tremendous challenges."

I think the fundamental question before this Committee today is, "What have we learned in 10 years of study and three assessment reports from the IPCC?" My sense is the Panel has fulfilled its mission as an independent, scientific adviser to the nations of the world. It is also my sense that the Committee can place great confidence in the notion that human activities are contributing to rising atmospheric concentrations of greenhouse gases with potentially adverse consequences for the environment and millions of people.

Uncertainty exists-as it does in almost all matters of public policy—but that uncertainty has been reduced significantly over the past decade. And some uncertainty does not always justify inaction. In 1989, Secretary of State James Baker III spoke to the IPCC. He stated that, "[W]e can probably not afford to wait until all the uncertainties have been resolved before we do act. Time will not make this problem go away." I agree with Secretary Baker.

Unfortunately too many individuals, companies, nations and some in the Congress have used the fact that we can never be absolutely certain of how a natural system as complex as the global climate will respond to confuse the debate and undermine any meaningful policies.

That is why 10 years since Secretary Baker made that statement and despite more conclusive science, our nation has done so little to resolve the threat of climate change. Our emissions-despite our pledge to cut them in the Framework Convention on Climate Change have only grown. I hope Mr. Chairman, that this hearing will help build a foundation for the Congress to move constructively toward lowering our greenhouse gas emissions and responding to the threat of climate change.

In closing, Mr. Chairman, I want to express my disappointment in those who now attack the IPCC because they do not like its scientific conclusions. They assail the process of the IPCC and the motives of individuals who have lead the IPCC effort. Dr. Lindzen and my colleagues Senators Craig and Hagel have submitted such testimony today. I have listened carefully to their comments-and I respectfully disagree. I believe the scientists involved in the IPCC have done their best to provide an independent and honest assessment of the state of knowledge of the world's cli(69)

mate. It is an extraordinary charge we have given them, and I do not question their tremendous effort.

I thank the IPCC for its work. I thank our panelists for joining us today. And I thank the Chairman for holding this hearing.

RESPONSES TO WRITTEN QUESTIONS SUBMITTED BY HON. JOHN MCCAIN
TO DR. VENKATACHALA RAMASWAMY

Question 1. The IPCC report states that climate models have evolved and improved significantly since the last assessment. However, the National Research Council reports indicates that US modeling capabilities trails those of Europe. Do you agree with that assessment?

I would like to first thank the Committee for the invitation to appear, and to present my testimony on climate change science. I am very appreciative of the thoughtful questions that have been put forward as follow-up to the testimony. In my testimony, as requested, I focussed exclusively on the scientific evaluations, following the details spelt out in the IPCC 2001 assessment. Partly because of the nature of the follow-up questions, I find that I have to go beyond the scope of the IPCC report, and include personal views in response to some of the questions.

Answer. On the first element under this question, coupled atmosphere-ocean climate models have evolved and improved significantly since the time of the previous IPCC assessment (IPCC, 1996). There is now improved knowledge of the physics based on theoretical and observational developments, including a longer observational record. For example, there is now an improved understanding of convection, radiation, boundary layer, and clouds, which constitute key climate feedback processes. These improvements have led to better representations of the physical processes in models and, therefore, increased credibility of the models to perform simulations of climate variations and change. There are now better simulations of climate, at least down to continental scales and over temporal scales from seasonal to decadal, including slight improvements in simulating El Niño. Confidence in model projections has also increased owing to the ability of climate models to maintain stable, multi-century simulations of climate; these are of sufficient quality for use in addressing climate change questions. Confidence in the ability of models to project future climates has been enhanced by the ability of several models to reproduce the warming trends in the 20th century surface temperature when driven by the known natural and anthropogenic forcings. Systematic intercomparisons of coupled climate models developed in recent years provides another line of evidence for the growing capabilities of such tools. Although there remain key uncertainties and quantitative aspects of key climate processes have yet to become robust, important scientific strides have been made in coupled atmosphere-ocean modeling since the last assessment.

The second part of the question touches upon a somewhat different issue viz., "US versus Europe's modeling capabilities". There are several sub-texts to be considered here. The first point is that there is no need to look upon the situation as a "US versus Europe" competition of an unhealthy type. It is more useful to consider our European counterparts as worthy collaborators in our joint quest to advance the knowledge in climate science. The investigation of climate and climate change is a massive scientific problem, and requires vast amounts of resources of various kinds in a globe-wide context, more than any one country could possibly support. To address this complex science, it is important to pursue the investigations in a cooperative and collaborative sense, recognizing that scientists in Europe (and elsewhere) may have as much and/or unique contributions to make to the advancements. It is in fact the recognition of this complexity and the need for a collaborative spirit that has led to IPCC's successful evaluations of the climate science, guided strictly by scientific bases and peer-reviewed publications. It is, however, incumbent upon US scientists to bear in mind always the highest traditions of science, and pursue the truth in an independent and original manner without biases.

Secondly, compared to Europe, and seen in purely computational facility and human brainware terms, it has become evident that the UK's Hadley Center (under the UK Meteorological Office) made a very focussed effort and posted substantive accomplishments, more than any other center in the world, during the latter half of the 1990s decade. There is one metric in particular that illustrates this point. The Hadley Center model has performed stable climate simulation integrations in excess of thousand years without flux adjustments—no other model in the world has been able to perform such integrations without flux adjustments/ corrections at the atmosphere-ocean interface. However, this model has been the only European climate model that has eclipsed the US achievements. It is important to note that no other

model from any of Europe's other climate science institutions can be said to be more advanced than those in the US, with regards to the metric cited above or, for that matter, other metrics of relevance for long-term climate change.

It is a matter of considerable concern (and indeed has been recognized to be so by the Academy report) that the computational ability of the US has suffered a serious setback in the past few years. While European institutions have not had to think of changing basic architectures of their computational systems and have been able to procure the fastest computers available, US institutions have found their ability hampered in the procurements of the fastest computers in the world. And, there have not been many competitive alternatives available in this regard to the US institutions. Besides decelerating the pace of scientific research in the US, this factor has also initiated uncertainties about potential future computing frameworks for climate modeling research.

It is unfortunate, too, that the brainpower (i.e. talented human resources) needed to tackle the climate science problem has also suffered in recent years in the US. While European institutions and Hadley Center in particular have been able to ensure that funding and institutional infrastructure continue to be favorable enough to attract young students and scientists, such that they have been able to readily recruit bright and talented youth emerging from the colleges, US has lagged severely in this respect. Hadley Center has not only recruited top-class youth but has also motivated them into focussed climate modeling exercises. The problems in the US include: lack of resources to motivate the top minds in the country to turn to and remain engaged in science, declining base funding which barely if at all keeps pace with inflation, and declining infrastructure resources with lack of steady commitments to maintain top-class climate centers.

The above elements, while very crucial, have to be juxtaposed with a third one that is at least equal in value to those stated above. This concerns the question of extraction of science from the climate model simulations and observations. Obviously, it is not just enough to have the best computer, infrastructure and human resources. A key question is how far has the science been actually advanced. Examination of computer model simulations, critically analyzing them in conjunction with observational data of various kinds, and making incisive and proper diagnostic interpretations are the hallmarks of success in scientific research. This element, together with the others above, constitutes, in my view, the definition of the term "modeling capabilities". In this regard, it is not at all clear that the US contributions, in terms of the peer-reviewed findings reported in journals or in the IPCC reports, are any less relevant in originality and substance than contributions from Europe, including those from the Hadley Center.

The Academy document, while rightly pointing out the limitations of computer hardware and brainware, has chosen to critique a somewhat narrower focus of the overall problem. It has not emphasized enough that scientific accomplishments and advancement of knowledge in long-term climate change require more than just hardware and brainware. In particular, it has paid less emphasis to how the US has fared in the third element mentioned above. While Hadley Center may have unquestionably led in the implementation of the most sophisticated physics and thus created the most stable climate model simulations to-date, US institutions doing research in climate change have likely been not far behind Hadley center in the overall diagnostic analyses of climate change-forcings, feedbacks and responses. Compared to other institutions in Europe, there is no question that the leading US climate change research centers have at least been on par, if not outshining them.

But, it is easy to become complacent. Thus, it is important that US take firm, proactive steps to ensure sustained advancements in computer power, assure itself of a continued stream of talent to engage in the science, spot infrastructure deficiencies and build up with steady commitments. In turn, it should be demanded that scientific research continue to provide an unbiased, well-grounded and critical appraisal of the understanding of climate change to policy makers.

Question 2. How many more scenarios were involved in this recent assessment report as compared to five years ago? Would the scenarios used 5 years ago result in the new predicted increases in sea level rise and global-average surface temperatures?

Answer. The IPCC 1996 climate change science assessment employed the IS92 suite of scenarios (6 in all), with the middle of the range being the oft-mentioned IS92a scenario. In the 2001 assessment, the calculations drew upon the IPCC Special Report on Emissions Scenarios (SRES), besides also comparing the results with those from the IS92a scenarios (see Figure 5, IPCC Summary for Policymakers). The SRES was a separate study from the Working Group I climate change science assessment. The SRES scenarios were drawn up based on a range of diverse assumptions concerning future demographics, population evolution, economic developments

and technologies. While a few of these new scenarios are similar to the IS92 set, some of the newer scenarios differ markedly from the earlier ones employed by IPCC. There were about 40 scenarios used in IPCC 2001, with 4 main groups or families, and with 6 "marker" scenarios. As an example, the IS92a scenario projection for carbon dioxide concentrations in this century is roughly comparable to that for the A1B and A2 scenarios. The IS92 and the newer scenarios represent quite a diverse collection of projections. Nevertheless, it is emphasized that the projections should be considered as sensitivity illustrations that employ a wide range of assumptions for the purposes of obtaining insights into the plausible projections of future climate changes due to anthropogenic emissions.

IPCC has discussed the projections of plausible future climates in terms of a range that is a consequence of the variety in the scenario assumptions. In arriving at the range of future climate change, IPCC 2001 considered the IS92 scenarios as well. The projections discussed in the 2001 report yield a range that encompasses the results of the IS92 scenarios, with the overall range wider now than in IPCC 1996. The change in the range from IPCC 1996 is due in part to the several new emission scenarios considered. The examination of both the IS92 and the newer scenarios in the 2001 report achieves the intent of surveying the effects due to an array of assumptions about emissions of radiatively-active species. Thus, the IS92a scenario (BaU) results for global-mean temperature and sea-level changes are indeed accounted for in the range cited in the 2001 report.

An important technical difference between the older and newer scenarios is the assumption of cleaner technologies in SRES which leads to differing considerations of the relative amounts of the projected concentrations of greenhouse gases and aerosols. In particular, the aerosol concentrations are affected by an earlier invocation of cleaner technologies in this century. As aerosols are short-lived, their concentrations are affected right away. Thus, the sulfate aerosol forcing concentrations (which yield a cooling) are projected to fall faster in the newer scenarios than was the case in the IS92 (e.g., IS92a) scenario. Greenhouse gas concentrations (including CO2) rise less rapidly than in IS92a for several, but not all, of the newer scenarios. An additional feature in the IPCC 2001 report was to use the scenarios in conjunction with different model climate sensitivities to approximately mimic the range in climate sensitivity that arises owing to uncertainties in the physical processes.

Taking into account the ranges provided by the assumptions leading to the greenhouse gases and sulfur emissions, and the range in climate sensitivity, the following results are cited by IPCC (2001). The presently (and the most recently) cited range for the global-mean surface temperature change projected in 2100 is 1.4 to 5.8 C; this is to be contrasted with the range of 1 to 3.5 C in IPCC (1996). The main reason for the upper end being greater and a wider range has to do with the lower sulfur emission projections in the present report relative to the IS92 scenarios. Lower sulfur emission means lesser importance of the role of cooling effect by aerosols relative to the long-lived greenhouse gases. The corresponding global sealevel rise in the 2001 report is 0.09 to 0.88 m. This is to be contrasted with 0.13 to 0.94 m in the earlier report. Despite a higher temperature projected at the upper end of the range, the sea-level projections are lower owing to improvements in models that now yield a smaller contribution from glacier and ice-sheet melts. It is reiterated that the scenarios used five years ago yield results that are within the range spelt out in the 2001 report.

Question 3. You have stated that a key aspect of climate change is that a greenhouse gas warming could be reversed only very slowly. Can you elaborate on that point and also comment on the value in sequestration in this process?

Answer. The major greenhouse gas being input into the atmosphere, CO2, has a long residence time owing to its chemical inertness. Its sinks act quite slowly; in particular, mixing into the oceans is very slow. Thus, it is expected that it would take a long time (centuries) to draw down the CO2 that has been emitted. Other greenhouse gases, which are less strong climate forcing agents compared to CO2, can be just as long-lived. In a general sense, there are several important climate forcing gases, with lifetimes varying from ten to upwards of hundred years (e.g., methane, nitrous oxide, halocarbons, sulfur hexafluoride). With the CO2 sinks tending to operate slowly, even if it were assumed that all emissions ceased at present, there would tend to be only a slow decrease in the atmospheric CO2 concentration. The long residence time factor implies that the radiative forcing due to the emitted CO2 will act for a long period of time. In addition, there is another timescale that has to be taken into account. This concerns the delay in the thermal response of the oceans owing to the long time it takes for heat to be diffused into or out of the deep ocean. At present, the climate is not in equilibrium with the present atmospheric CO2 implying that the complete impact of present-day CO2 is yet to be fully realized. Thus, while atmospheric CO2 is not in equilibrium with the present

emissions, the climate is not in equilibrium with the present-day atmospheric concentrations. Thus, even if the atmospheric CO2 concentration were to be stabilized at a particular value and at a particular time, the climate effects can be expected to be felt well after this point is reached e.g., continued sea-level rise. The longer this forcing element is there in the atmosphere, the further the delay in the recovery of the climate system. In view of the slow but long associated timescales, greenhouse gas warming can be reversed only very slowly. In this regard, the possibility of non-linear and irreversible climate changes owing to feedback mechanisms existing in the system cannot be overlooked.

Sequestration process, meaning a mechanism to draw down the CO2 thus reducing its atmospheric composition, would presumably achieve the objective of lowering the quantum of this forcing agent in the atmosphere. This is a conceptually attractive idea and one that is engaging vigorous research attention. Thus far, however, the research has yet to be translated in robust quantitative and practical terms, including cost-effectiveness. Early results are somewhat tentative on the overall effectiveness and scaling with respect to natural sinks, especially on multi-decadal to multi-century time scales. Note that even if it were possible to sequester all future CO2 emissions, climate would still continue to warm and sea-levels would continue to rise, as noted above, because of the slow climate response to the existing atmospheric concentrations. Nonetheless, there are some interesting ideas concerning sequestration under active investigation which may shed further insights into this problem in the near future.

Question 4. The report states that a special need is to increase the observational and research capabilities in many regions, particularly in developing countries. How is this need being addressed by the International community and how much will it cost?

Answer. I will confine my remarks here only to the principal shortcomings. A key point to note is that observational networks are on the decline. Long-term monitoring of climate variables even the most common and obvious ones, such as surface temperature and precipitation, are not being done with the spatial distribution and frequency that is necessary to achieve a comprehensive documentation of regional climate variations and change. The problem exists to varying degrees in all parts of the world, but is especially acute in the developing countries. Lack of adequate and sustained funding, the high cost of initiating and maintaining reliably measuring equipment, are major issues. There are, however, other factors as well, such as the lack of an appreciation of the significance of long-term monitoring, which inhibits a sustained high-quality data collection. Further, data gathering tends to not be a high-visibility exercise. The worth of such routine measurements does not really show up till at least a decade's worth of data has been collected. By then, due attention to such important technical issues as instrument maintenance and consistency in program management usually tend to wane, resulting in the difficulty of compiling a reliable dataset. Insofar as developing countries are concerned, the problems include acquisition of state-of-the-art equipment, ability to sustain funds for maintenance, and quality control. A recurring problem is the lack of welltrained human-power. As is true even the developed world, the scientific challenge posed by climate change detection is unable to compete with the marketplace attraction of other professions. Very few scientists' careers have advanced solely as a consequence of painstaking data collection over a long period of time, a timescale that is also considerably longer than typical program management tenure and fiscal considerations. Thus, especially among young scientists worldwide, there is a lack of a motivation to undertake these routine but necessary observations. This holds true in both developed and developing countries.

Automation and advances in remote sensing, which would obviate the need for humans to attend to the observational tasks, are not yet in full gear in this field in the developing countries. Amidst the pessimism, however, it is important to point out that some observational activities have indeed flourished e.g., measurements of CO2 at a few sites around the world for the past 3 decades and more. This effort is particularly exemplary and is worth emulating for other climate variables as well. The situation with regards to modeling capabilities, and diagnostic analyses combining models and observations is not dissimilar from the tenor of the issues plaguing observational datasets, as noted above. The lack of talented minds applying themselves to science in general and to this scientific aspect in particular needs to be improved. There is a need to improve this situation especially in the developing countries, where the educational and scientific infrastructure are at times too weak to sustain a orderly, long-term research commitment. International research organizations are trying hard to remedy the situation, but are being strained by funding inadequacy and the need to keep pace with the growing complexity of the climate system.