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The CHAIRMAN. Thank you very much.

Dr. McCarthy, welcome.

STATEMENT OF JAMES J. MCCARTHY, DIRECTOR, MUSEUM OF COMPARATIVE ZOOLOGY, HARVARD UNIVERSITY

Dr. MCCARTHY. Thank you. Good morning, Mr. Chairman, and members. I am James McCarthy, professor of biological oceanography at Harvard University, where I am also the director of the Museum of Comparative Zoology, and I also head our undergraduate program on environmental science and public policy, but the reason I am here today, of course, is in my capacity as the cochair of the Intergovernmental Panel on Climate Change Working Group 2. I and a colleague, Osvaldo Canziani, a meteorologist from Argentina, have co-chaired this Working Group.

The charge of this Working Group was to assess evidence for impacts, adaptations and vulnerabilities associated with climate change. We began this assessment in the autumn of 1997, and conIcluded it earlier this spring.

Mr. Chairman, I read the testimony related to climate change submitted to your Committee last year on three occasions, May, July, and September. In each case for which evidence of climate change impacts were cited, we now have greater confidence that these effects are widespread and more conclusively linked to climate change.

Some witnesses presented evidence of no change in climate, or absence of climate change impacts. In my judgment it was the selection of data for a particular region or particular time period that led them to these conclusions. This, Mr. Chairman, is why the work of the IPCC is so important. Some nations have sponsored and will continue to sponsor studies that may show, quite correctly, that recent data for their localities do not show evidence of change. The IPCC focus is on broad patterns and generalizations that arise from these patterns.

Dr. Neil Lane reported to you that 89 of 99 plants examined in the District of Columbia are blooming a full week earlier now than they did a mere 30 years ago, but is this true everywhere in the globe? Probably not. Were a survey in some other city to reveal no such change, would this cause one to doubt that there had been change in Washington, DC.? Certainly, it would not.

From the IPCC assessment, what is now clear is that this type of effect in plants and animals over the last few decades is evident on all continents, and in 80 percent of the published cases, the change in the distribution of animals or their biology is consistent with local changes in temperature. This is strong evidence of biological response to climate change.

So, we have already seen effects of recent climate change in ecosystems. While none of these might be classified as dangerous per se, it is unlikely that they will be reversed within our lifetime by any action that we might take today to reduce the rate of climate change. And the rate of climate change projected for the 21st Century, as we have just heard from my colleague, is, on average, 2 to 10 times the rate observed in the 20th Century.

In all likelihood, this projected change will lead to displacements of species, and perhaps extinctions, especially in tropical ocean and

arctic ecosystems such as we were just hearing from Senator Stevens. But for the lives and livelihood of humankind, the largest associated effects of these shifts in organisms will be in regional agricultural productivity, and in distribution of disease organisms and their vectors. North American and Northern Eurasian agriculture may, in fact, be enhanced, albeit with a northward shift. However, the tropical and subtropical regions will be hardest hit, with potentially serious losses of agricultural capacity.

Human systems other than agriculture are also being affected by climate change, some from general warming, such as with human health, but others from an increasing frequency, intensity, and persistence of extreme events.

If climate change is steady and smooth, most of it may be accommodated or adapted to without great cost, but if the path is bumpy the story becomes very different. There is no good news in extreme events. These are inherently disruptive, and one need only look at the last 5 years to see the global evidence of this, with floods and mudslides of unprecedented proportion in Honduras in 1998, where more than 10,000 lives were lost, and Venezuela in 1999, where more than 25,0000 lives were lost, and on other continents as well, in Africa, with Mozambique and Kenya, in Asia with China and North Korea.

Our report, Mr. Chairman, summarizes our assessment of the published literature on the likely effects of projected changes in climate on a suite of systems and economic sectors, and for eight broad regions of the globe we identify the most serious vulnerabilities. The tropical and subtropical regions, many of them already water-stressed and facing serious questions of food security, will be hardest hit. This disproportionate impact is in no small part because these regions, many with developing countries, are poorly equipped to adapt. In many cases they lack the infrastructure and simple resources such as in the case of public health measures. But it is also incorrect to assume that northern industrialized nations will be spared serious effects of climate change within their own sovereign territories. The fraction of their citizens who are most vulnerable to heat waves, floods, and droughts, will increase.

In summary, Mr. Chairman, some of the climate changes projected for the future have positive effects: less human winter mortality in some regions, enhanced crop growth in others, for example, but most systems and most sectors and most people will be adversely affected by this climate change. For most people, the projected rate of change will simply exceed capacities to adapt to even gradual change, let alone a future with more frequent, intense, and persistent extreme events.

Our report calls attention to the need to explore all opportunities to reduce potential adverse effects of climate change by enhancing adaptive capacity, as with some of the issues that were being addressed by Senator Stevens.

Thank you again, Mr. Chairman, for this opportunity to present some of our results to your Committee. I realize that in addition to the results of the assessment themselves, you and members of your Committee may have some questions about the methods and procedures of the IPCC. I refer here specifically to the last portion of my submitted testimony, in which I discussed the actual prepa

ration of the Summary for Policymakers and, with all due respect, I think Senator Hagel has been misinformed as to how this actually occurs.

In my written testimony, I have remarked on this process, and I will be happy to discuss further any aspect of the findings of either the procedures of the IPCC Working Group 2, or its results, as you wish.

Thank you.

[The prepared statement of Dr. McCarthy follows:]

PREPARED STATEMENT OF JAMES J. MCCARTHY, DIRECTOR,
MUSEUM OF COMPARATIVE ZOOLOGY, HARVARD UNIVERSITY

Thank you, Senator McCain, for this opportunity to address the Committee on Commerce, Science, and Transportation. My name is James J. McCarthy, and I am a Professor of Oceanography, the Director of the Museum of Comparative Zoology, and the Head Tutor for undergraduate students studying Environmental Science and Public Policy at Harvard University.

For nearly four years I have co-chaired Working Group II (WG II) of the Intergovernmental Panel on Climate Change (IPCC). The focus of this working group has been to assess potential impacts, adaptations, and vulnerabilities to climate change. In my letter of invitation to this hearing you have asked that I comment on the results and conclusions of the IPCC WG II and other related issues that I wish to bring to the attention of the Committee.

The new WG II report, Climate Change 2001: Impacts, Adaptation, and Vulnerability, is the most comprehensive and up-to-date scientific assessment of the consequences of, and adaptation responses to, climate change. The report:

• evaluates evidence that recent observed changes in climate have already affected a variety of physical and biological systems.

makes a detailed study of the vulnerabilities of human populations to future climate change, including associated sea-level rise and changes in the frequency and intensity of climate extremes such as floods, droughts, heat waves and windstorms, and taking into account potential impacts on water resources, agriculture and food security, human health, coastal and other types of settlements, and economic activities.

• assesses the potential responses of natural environments and the wildlife that inhabit them to future climate change and identifies environments at particular risk.

• considers how adaptation to climate change might lessen adverse impacts or enhance beneficial impacts.

• provides an overview of the vulnerabilities and adaptation possibilities by major region of the world (Africa, Asia, Australia/New Zealand, Europe, Latin America, Polar Regions, and Small Island States).

contrasts the different vulnerabilities of the developed and developing parts of the world and explores the implications for sustainable development and equity con

cerns.

Research on climate impacts has grown considerably during the five years since the last IPCC assessment, and much has been learned regarding the potential risk of damage associated with projected climate change. In particular, this research has added new understanding of vulnerabilities to climate change across a spectrum of ecological systems (forests, grasslands, wetlands, rivers, lakes and marine environments) and human systems (agriculture, water resources, coastal resources, human health, financial institutions, and human settlements).

Observational evidence of changes has accumulated in many physical and biological systems (e.g. glacial melting, shifts in geographic ranges of plant and animal species, and changes in plant and animal biology) that are highly consistent with warming observed in recent decades. These observations are adding to our knowledge of the sensitivity of affected systems to changes in climate and can help us to understand the vulnerability of systems to the greater and more rapid climate changes projected for the 21st century. A number of unique systems are increasingly recognized as especially vulnerable to climate change (e.g. glaciers, coral reefs and atolls, mangroves, boreal and tropical forests, polar and alpine ecosystems, prairie wetlands, and remnant native grasslands). In addition, climate change is expected to threaten some species with greater probability of extinction. Potential changes in the frequency, intensity, and persistence of climate extremes (e.g. heat waves, heavy precipitation, and drought) and in climate variability (e.g. El Niño--Southern Oscil

lation) are emerging as key determinants of future impacts and vulnerability. The many interactions of climate change with other stresses on the environment and human populations, as well as linkages between climate change and sustainable development, are increasingly emphasized in recent research and preliminary insights from these important efforts are reflected in the report.

The value of adaptation measures to diminish the risk of damage from future climate change, and from present climate variability, was recognized in previous assessments and is confirmed and expanded upon in the new assessment. Understanding of the determinants of adaptive capacity has advanced and confirms the conclusion that developing countries, particularly the least developed countries, have lesser capacity to adapt than do developed countries. This condition results in relatively high vulnerability to damaging effects of climate change in these coun

tries.

MORE SPECIFIC NEW FINDINGS

The effects of recent climate change are now clearly evident in many natural systems. Changes in the distribution of species as documented in the fossil record have long been used as an important diagnostic of past climate. In addition, it is well known that the seasonal behavior of many species, such as migrations and reproductive behavior (e.g. flowering time and egg laying) are sensitive to temperature. In the past few decades substantial changes in these characteristics have been noted for many species, and for 80% of the cases for which such changes could plausibly be linked to temperature, the biotic changes were consistent with changes in regional temperature.

The documented changes in Arctic sea ice cover, both its thinning and its shrinkage during summer, affect polar ecosystems. The shrinkage that is occurring has averaged 3% per decade for the entire Arctic over the last three decades. Throughout Northern Hemisphere freshwater ecosystems the ice-free season is now nearly 2 weeks longer than it was a century ago, which is consistent with an average annual temperature increase of about 1°C. Increased access for ships is a positive aspect of this trend. During the summer of 2000, for the first time in recorded history, a RCMP ship transited the Northwest Passage without touching ice. With summer ice-free conditions in the Arctic expanding poleward, ecosystems will shift accordingly. Marine mammals, such as walrus, certain seals, and the polar bear have evolved with a dependence on ice for successful feeding and rearing of their young. As summer ice retreats from land earlier in the season and reaches greater maximum distances, the success of these species will be challenged. Now, in the span of a single human generation, observations point to a coherent shift in the pattern of temperature sensitive systems on all continents.

Many human systems are also inherently sensitive to climate change. Examples in the IPCC report include:

• changes in potential crop yields, especially reductions in most tropical and subtropical regions.

⚫changes in water availability, especially losses in the sub-tropics.

• an increase in the number of people exposed to vector born diseases like malaria and water borne diseases like cholera.

• increased losses of lives, livelihood, and property from heavy rains and sea level rise.

Already the increased frequency and intensity of extreme precipitation events has taken a heavy toll. Devastation caused by floods and mudslides in tropical to temperate regions on all continents in the last decade has been without precedent. While a gradual increase in temperature might be accommodated by many natural and human systems, the projected increases in frequency, intensity, and persistence of extreme events has the potential to be enormously disruptive. Moreover the impacts of these changes will fall disproportionately on the poorest peoples. While this may be an obvious conclusion when comparing certain developed and developing countries, it will also be true within a developed country. The fraction of the population that is vulnerable to an extreme heat wave or flood will increase with the severity of the extreme event.

Many of the most devastating aspects of climate change will occur in tropical and subtropical_regions, where 70% of the world's population live, many in developing countries. These are the regions that will be the most water stressed, suffer the greatest potential losses of agricultural capacity, and be most vulnerable to the expanded ranges of certain infectious diseases. Even allowing for possible benefits from climate change in some temperate regions, such as net gains in potential crop yields, the negative aspects of climate change in subtropical and tropical regions are likely to offset these positive aspects even assuming there would be no infrastruc

ture or financial obstacle to the distribution of resources, i.e. food, moved from one region to another.

Thus the following are evident in the recent IPCC assessment:

• responses to climate change are already occurring in natural and human sys

tems.

• it is highly likely that climate changes in the 21st century will be 2—10 faster than those of the 19th century.

• increased frequency and severity of extreme events will be costly to natural and human systems.

Given the inertia in human system-climate system linkages, these findings lead inevitably to the conclusion that even the most optimistic scenarios for mitigating future climate change are unlikely to prevent significant damage from occurring. This is not to say that mitigation efforts such as a fully implemented Kyoto Protocol won't be effective; rather that their effect won't be evident for decades. Thus, an important finding of the IPCC is that adaptation will be absolutely necessary to minimize damage that is projected from future climate change. Limitations in adaptive capacity will make some regions and some peoples of lesser means more vulnerable to the impacts of climate change. Natural systems will be affected in all regions from polar to tropical on all continents. Human systems will, however, be most vulnerable to climate change in Africa, Latin America, and Asia where current adaptive capacity is low.

If we wish to minimize the loss of lives, livelihoods and property that will occur during our inevitable transition to a warmer world, it is imperative that we redouble efforts to both minimize the emissions of fossil fuel combustion products and prepare peoples and systems as best we can for the disruption that will ensue with the climate change that is now projected for the 21st century.

COMMENTS ON THE IPCC PROCESS

Nowhere can one find a process that produces a report on the understanding of a broad area of science that is more inclusive in its coverage of contemporary scientific views, or more broadly vetted by the scholarly community than with the IPCC. The basis of the assessment is the peer-reviewed published scientific literature. Every effort is made to be thorough, and serious attention is given to disparate results and conclusions in this literature. To the extent possible, degrees of likelihood are assigned to summary statements, especially those on projected climate conditions and climate impacts.

Currently about 100 governments participate in the IPCC, and all were invited to propose the names of experts who could serve as authors of this report. More than one thousand nominations were received for WG II authors, with supporting documentation listing the nominees' publications in scientific journals. It should be noted that the authors of IPCC reports work without financial compensation for their efforts on behalf of the IPCC.

The report of WG II was drafted between July 1998 and February 2001 by 183 Lead Authors. In addition, 243 Contributing Authors, from nearly 70 countries, submitted draft text and information to the Lead Authors. Drafts of the report were circulated twice for review, first to experts and a second time to both experts and governments. Comments received from 440 reviewers were carefully analyzed and assimilated in a revised the document, with guidance provided by 33 Review Editors. The full report was then condensed into a 70-page manuscript, known as a Technical Summary (TS), and it was then further condensed into a 20-page manuscript known as a Summary for Policy Makers (SPM). The TS and SPM (along with a revision of the full report that reflected the earlier government and expert review) were then sent out for a final review coordinated by governments.

Comments from this final review were then used to prepare a revision of the SPM and TS, and a plenary of the Working Group was convened to consider final approval of the SPM. This involved about 150 delegates from 100 nations, drawn from each nation's departments and ministries of state and science. The plenary met for four days in Geneva (Switzerland) in February 2001 to vet the SPM line-by-line, proceeding to the next line only when all delegates agreed to do so.

While the science that underpins SPM was clear to its authors as their document was taken to the plenary for approval, the plenary is actually the final stage in this process of clarifying the message for policy makers. Discussions in the course of the plenary called attention to words and sentences that were perceived to be unclear by a delegate, and suggested changes were made as long as they were not inconsistent with the underlying science. By the conclusion of the meeting the Summary for Policymakers was approved in detail and the full report accepted by all delega

tions.

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