« PreviousContinue »
Answer. First, it is important to understand that El Niño and la niña are the opposite phases of an oscillation that is atmospheric and oceanic based. As such, la niña reflects cold ocean waters in the tropical Pacific while El Niño reflects the opposite conditions, warm waters. Present-day Global Circulation Models are only now beginning to show success in simulating important ocean-atmosphere oscillations such as the El Niño/Southern Oscillation. Neither of the models used in the National Assessment has a fully satisfactory representation of the El Niño/la niña oscillation, and it is likely that this has lead to some of the differences between model projections. The Global Climate Model that has been most successful in reproducing the El Niño/la niña events, primarily because of its higher resolution, is the Max Planck Model from Germany. Unfortunately, based on the NAST's selection criteria, we could not use this model as a primary model, but the NAST was able to point out that this model projects a major increase in the intensity of both El Niño and la niña events as the globe warms. This could be very important, and in our Research Needs section of the National Assessment the NAST points out the importance of more research related to climate model inter-comparisons, representation of important ocean processes, and analysis of possible influence of climate change on existing patterns of climate variability. Question 5. Do you anticipate that any of the ongoing university regional studies will contradict the findings of the current draft report?
Answer. I do not anticipate that the any of the ongoing studies will contradict the current National Assessment Draft Report, but I would be surprised if they did not add additional insight into important issues and uncertainties. In assessing such a broad range of science, economics, and sociology, it was very clear to us that new understanding and insights were occurring continuously. Most often however, these insights made incremental additions to our understanding. A good example of this are the incremental advances in our understanding about global change as reflected in the series of Inter-governmental Panel on Climate Change Assessments completed during the 1990s. It is rare in science, that a discovery or theory completely displaces the old paradigm. We acknowledge that such things can occur however, such as the discovery of the “Ozone Hole” or Einstein's Theory of Relativity.
RESPONSE TO WRITTEN QUESTIONS SUBMITTED BY HON. JOHN MCCAIN TO
DR. ANTHONY C. JANETOS Question 1. Some critics of this report charge that the Administration has ignored scientific and analytical procedures, and instead produced an advocacy-driven document. Given that most scientific studies are not open to the public, do you believe that “value” was added to the process by involving the public in this manner?
Answer. The public has been involved in two ways throughout the assessment process. First, during the workshop phase of the process, in which more than twenty workshops were held around the country, broad public participation was sought. The role of the workshop participants was primarily to identify environmental issues of concern to people in the different regions of the U.S. This input was then used to help decide which issues of importance within each region would be followed up in scientific studies.
The second way in which the public was involved was opening the Synthesis reports up to a public comment period, at the specific request of the Congress. We received many comments from people who otherwise might not have had the opportunity to read such a report at this stage in its development. Some of these comments have been quite insightful and helped us improve the document as a method of communication with a broad readership.
It is correct that most national scientific processes have not been so open to soliciting input from the public. I argue that our process has been enhanced by the public participation that we received, without resulting in an advocacy-driven document. We have focused on issues that people perceived to be important to them, and not just on issues of interest to the scientific community. At the same time, we were able to bring up-to-date scientific knowledge and methods to bear on the issues that had been identified. Objective scientific and analytical procedures and methods have been used throughout. Our objectivity has been ensured by extensive peer review. Would you also discuss the level of participation from the private sector?
Answer. The private sector has been involved in several different ways. Our oversight panel is broadly representative of several different sectors, including academia, the for-profit private sector, and non-governmental organizations (NGO's). The National Assessment Synthesis Team and other contributors to the national reports include individuals from all these sectors as well, plus experts from government research laboratories. Many individuals in the private sector have reviewed all or part of the reports, and have offered their comments to us. Finally, many of the regional workshops included participants from the private sector, who were important contributors to the process of identifying issues for scientific analysis. Question 2. Can you describe the peer review process that the assessment team incorporated into its findings?
Answer. The peer review process had several ps. First was a round of technical peer review on the initial drafts of the national reports, which began in November of 1999, and continued into January of this year. We received more than 300 comments from individuals who identified themselves as technical experts in the many different aspects of the report. This technical peer review included experts in the government agencies, as well as academia, the private sector, and NGO's. The second step was submitting the entire report to a list of about 20 experts identified by our oversight panel, who were charged with evaluating the entire structure of the report, its responsiveness to its original intent, and the strength of the findings and conclusions. Throughout, we have had the benefit of comments from our oversight panel.
The National Assessment Synthesis Team has considered every written comment that it has received. We have responded to comments in writing, documenting either how the comment has been taken into account, or why we have decided not to do so. These responses to comments have also been shared with our oversight panel. Question 3. How did your "bottom up” approach to the assessment report impact the findings or scope of your work?
Answer. I believe that the approach of identifying issues through involvement of the public in the series of workshops did affect the scope of the work. Specifically, it enabled us to focus on the issues viewed as most important by the participants of the workshops. However, the analysis of those issues was done by experts, so that the actual findings themselves are the result of objective analysis. Question 4. Did the oversight panel for the National Assessment Synthesis Team offer any cautious or contradictory statements throughout the reporting process?
Answer. The oversight panel has been cautious throughout, and has been espe cially helpful to us in ensuring that we have described accurately the scientific basis for our findings, and been open about the degree of uncertainty that remains. They have not provided contradictory statements.
RESPONSE TO WRITTEN QUESTIONS SUBMITTED BY HON. JOHN MCCAIN
TO DR. RAYMOND W. SCHMITT Question 1. Your written statement mentions that the ocean is the long term memory of the climate system. Would you discuss what methods are available to retrieve that long-term memory?
Answer. Most of the heat energy reaching Earth is absorbed into the upper ocean at low to middle latitudes. A significant fraction of this is used to heat and moisten the atmosphere on a daily basis, causing the winds and rain we experience as weather. But over the course of the seasons, large amounts of heat are stored within the ocean during spring and summer for release in the winter. This is the basic moderating influence of the oceans on climate; the vast heat capacity of the oceans prevents the winter from becoming too cold, and the summer from becoming too hot, especially in areas near the coast. But we have also found that ocean currents are capable of moving tremendous quantities of heat around the planet. This has an essential role in the climate system, fully half of the transport of heat from equator to pole is accomplished by the slow-moving, high heat-capacity ocean, with the other haff of the heat transport carried by the fast-moving, low heat-capacity atmosphere. The atmosphere cycles its water vapor and heat within two weeks, so it has only a short-term memory of past conditions. However, the ocean's heat-content is so large its memory time is decades to centuries, when the deep ocean is considered.
The way to retrieve and interpret the long term climate memory of the oceans is to measure the temperature at depth. Satellites provide an estimate of the temperature of the ocean in a thin surface layer but tell us nothing about the deepreaching temperature signals necessary to help predict the climate a season or even a decade ahead. New technology of profiling floats (the ARGO program), new profiling moorings that measure temperature and salinity and maintenance of traditional ship-based observations will all help to acquire data on the deep temperature and salinity of the ocean. We will never decipher the mysteries of the climate system without measuring the dominant portion of its heat content that resides in the
Question 2. Would you briefly discuss the importance of ocean salinity (or salt content) to climate studies?
Answer. Salinity variations have nearly as much influence on seawater density as temperature changes. This means that in the high latitude ocean salinity plays a very important role in determining whether the surface waters will be dense enough to sink and become deep water. Salinity can be decreased there by rain fall, river runoff and ice melt. If deep water ceases to form then the “thermohaline” circulation is disrupted and the warming influence of the North Atlantic on American and European weather is much reduced. Increased rainfall in high latitudes and subsequent collapse of the thermohaline circulation is a prediction of global warming models, with dramatic consequences for climate. However, the ocean models and measurements are presently inadequate to say whether thermohaline collapse is probable or even possible with global warming. In the tropics, high rainfall rates can cause low salinity water to collect at the ocean surface and modify the ocean's transfer of solar heat to the atmosphere. Salinity variations in the ocean reflect the workings of the greater part of the global water cycle; a mere 1% of the rainfall on the Atlantic ocean would double the discharge of the Mississippi River. Yet salinity is a very poorly monitored variable; for many areas of the ocean, there has never been a salinity measurement. Thus, it is very important that we begin to make
ch greater use of new technology such as ARGO floats, moored an drifting buoys and ships to better define the patterns of salinity variation in the ocean. Only then will we achieve an adequate understanding of the global water cycle and its variations which are so important to society. Question 3. You mentioned that because of computer limitations, many models must treat the ocean as a very viscous fluid, more like lava or concrete than water. What are the implications of this assumption?
Answer. The models that are run for climate predictions cannot resolve or represent the smaller scales of variability in the ocean. This means that the many eddies and fronts we find in the real ocean (100 km in size and smaller) are not in the models. This introduces a number of defects in the models even for the large scales which are well resolved. For instance, some currents are driven by eddies, and without eddies such currents are not found in the models. Also, the ocean's interior mixing processes are known to be caused by internal waves, yet there are no internal waves in the models. Mixing controls the patterns of the deep. currents, which are notoriously wrong in the models. The problem gets worse for climate projections of decades or centuries, with many ocean phenomena missing or seriously misrepresented. Without an accurate portrayal of ocean dynamics, prediction of future climate states is fundamentally impossible. Question 4. Your written testimony states that it is unlikely that we will have the necessary computer power over the next 160 years, even with an increased order of magnitude every 6 years, to simulate the smallest ocean mixing processes. What are our alternatives to gain a better understanding of these processes?
Answer. Study the real ocean. We can develop a better understanding only through dedicated “process” studies focussed on these different phenomena. This allows the development of “parameterizations” of the small scale processes that can be used in the numerical models. The United States had a significant research effort on small-scale ocean processes during the cold war through support of the Office of Naval Research, but funds from that source are now much diminished. There is a great need for a revitalization of such work in order to bring the ocean climate models toward some semblance of reality.
RESPONSE TO WRITTEN QUESTIONS SUBMITTED BY HON. JOHN MCCAIN
TO DR. S. FRED SINGER Question 1. The report states that by using the two selected computer models, a plausible range of future actions are captured, with one model being near the lower end and the other near the upper end of projected temperature changes over the U.S. Do you agree with this statement?
Answer. The National Assessment Report chose two climate models (out of perhaps two dozen) to provide scenarios for the 21st century. The selection criteria are not readily apparent. One model came from the Canadian Climate Center; it predicts extreme temperature rises over the U.S. (of 11°F by 2100). The other model chosen was produced by the Hadley Center in Britain; it predicts less extreme temperatures.
The main point, however, is that BOTH models are already too high and therefore proven wrong by the temperatures observed in recent years. As shown in my testimony, there has been no appreciable warming over the U.S. since about 1935, according to the analysis by Dr. James Hansen of NASA-GISS. Notwithstanding the oral response by Tom Karl, virtually the same is true for the analysis published by NOAA-NCDC.
To verify this, it is only necessary to view the disparity between the observed temperatures (see my written testimony) and the calculated temperatures (see written testimony of Kari/Melillo/Janetos). Question 2. What are your thoughts as to why regional forecasts from the climate models disagree so strongly in some areas and not as much in others?
Answer. At the present state-of-the-art of climate models, regional forecasts are even worse than those for global averages. No reliance whatever should be placed on them. The strong disagreements between the model predictions themselves provide adequate confirmation for my statement. Question 3. Your written statement mentions that a careful analysis shows that the warming of the early 1990's actually slows ongoing sea level rise. Can you explain this finding?
Answer. Sea levels have been rising for about 15,000 years, since the peak of the last ice age. The total rise has been about 400 feet. Sea levels are continuing to rise at a rate of about 7 inches per century, and will continue at about that rate for several millennia more as slow melting continues in the Antarctic.
As global temperatures fluctuate (no matter whether from natural causes or possible human causes), the ongoing sea level rise may be expected to show slight modulations; it may slow down for some decades or it may accelerate. It all depends on whether a warming of the oceans produces a greater or lesser effect than an accumulation of ice in the Antarctic from increased ocean evaporation and subsequent precipitation. (These two effects on sea level oppose and nearly cancel each other.)
When we investigated what happened during the major warming between 1920 and 1940, we found empirically that the rise in sea level slowed down. We therefore expect that any future warming, unless extreme and sustained over many centuries, will likewise reduce the rate of sea level rise rather than accelerate it. The existing fears about rising seas from greenhouse warming have no scientific foundation whatsoever. They are based on hype rather than observed facts. Question 4. Do you accept the claim that the 20th century was the warmest of the past 1000 years?
Answer. The claim that the present century is the warmest of the past 1000 years relies on the “hockey-stick” temperature graph (Mann, Bradley, and Hughes, Geophysical Research Letters 1999). It is derived from various proxy data rather than thermometer records; yet it has been widely cited. It forms the cornerstone of the claimed “discernible human influence” in the Summary for Policymakers of the IPCC-Third Assessment Report.
The graph is actually a composite of two records: (i) temperatures from “proxy” data (tree rings, etc.) going back to 1000AD; and (ii) a superimposed global instrumental (thermometer) record of the past century.
Close examination reveals that the proxy record stops in 1980 and therefore does not independently support the post-1980 temperature increase suggested by the thermometer data. Thus there is no evidence for a substantial warming since 1980 (or even since 1940). There is no evidence for the claim that the present century is the warmest of the past 1000 years. And there is no evidence to back the claim of a “discernible human influence on global climate.
PREPARED STATEMENT OF HON. LARRY E. CRAIG, U.S. SENATOR FROM IDAHO Mr. Chairman, thank you for inviting me to testify at this very important hearing. On June 16, 2000, I spoke on the Senate Floor about the Administration's recently released draft National Assessment Synthesis Report. I ask that a copy of that Statement be included in the record of this hearing.*
Mr. Chairman, the potential of global climate change is one of the most important environmental issues of this new century. The stakes are high. Worst-case scenarios involving rising temperatures and sea levels scare many people. On the other hand, premature government action to cut back energy use to levels lower than those in the growth-oriented nineties could cool the economy faster than it cools the climate.
What is required at this time, Mr. Chairman, is steady and thoughtful leadership. Responsible government includes environmental stewardship. However, the ultimate obligation of government is to protect freedom. By freedom I mean the opportunity to achieve one's true potential as an individual, a community, or a nation: the freedom to grow!
* The information referred to was not available at the time this hearing went to press.
Freedom spawns discovery and innovation. Discovery and innovation solve problems and create opportunities. This is the true spirit of America.
Mr. Chairman, today you will have the co-chairs of the National Assessment before you. These are accomplished men with impressive scientific backgrounds. The Committee will have the opportunity to question them on a document that I believe is long on fear and short on conclusive science.
Let me lay-out some of the reasons why I am so concerned about this document.
The National Assessment process was authorized under the Global Change Research Act of 1990 but did not officially begin until January, 1998—one month after the Kyoto Protocol. The final report was expected in January, 2000, but was delayed.
Last year, in the Fiscal Year 2000 appropriations, Congress directed that all research used in the National Assessment must be subjected to peer review and made available to the public prior to use in the Assessment, and the Assessment must be made available to the public through the Federal Register for a 60 day public comment period. This was not challenged by the Administration.
The Administration released a “draft” summary report on June 12th of this year by posting it on a website and publishing a notice in the Federal Register that it was available for comment until August 11th. This action is clearly at odds with Congressional intent. The underlying regional (geographic) and sector (health, agriculture, forests, water, coastal) work that was to have served as the basis for the summary report has not been completed or made available for review.
In a June 30th letter to Congressman James Sensenbrenner, Chairman of the House Committee on Science, Neal Lane, who testified before this Committee on May 17th Mr. Chairman, stretched credibility in defending this action. Although taxpayer funds were provided to support the work, he claimed the underlying reports were not “federal” reports and therefore not covered by the earlier Congressional guidance. The underlying reports are to be completed over the next year or so and published by the respective teams working on them.
Mr. Chairman, a question that begs an answer is: Why the rush to release the National Assessment? The premature release of this document allows for more polarizing advocacy. Although supposedly a “draft” report published for technical review and comment, it was trumpeted by President Clinton on the day of its release and served as a basis for repeating tired claims:
“It suggests that changes in climate could mean more extreme weather, more floods, more droughts, disrupted water supplies, loss of species, dangerously rising sea levels.”
It's easy to miss (or ignore) the qualifications to these predictions and simply report that the Assessment forecasts dire changes in climate in the future. For example, a page one story in The New York Times on June 12th carried the headline: "Report Forecasts Warming's Effects—Significant Climate Changes Predicted for the Country."
In Texas, a July 4th story by the environmental reporter at the Dallas Morning News reported on action by five environmental groups asking Governor Bush—“to launch a Texas assault on global warming, which scientists say could heat up North Texas in the next century.” The story went on to discuss the draft National Assessment including the comment—“Two computer simulations of the future of Texas climate show sharp rises in the July heat index, with the worst impact in North Texas.”
Not everyone has been misled. The Wall Street Journal published an article entitled: “U.S. Study on Global Warming May Overplay Dire Side” on May 26th, in anticipation of the impending release. A similar story ran in The Detroit News on May 28th. Numerous Op-eds and Letters to the Editor have also run.
However, Mr. Chairman, the early release of this document raises more intriguing political questions than helpful probative scientific ones. For example, it puts the Assessment on a timetable for inclusion in the UN's Intergovernmental Panel on Climate Change's “Third Assessment Report” on climate change which is due to be finalized next year. In fact, Mr. Chairman, I have been informed by staff that drafts are already circulating for comment and these drafts include references to the U.S. National Assessment.
It is becoming clear that the June 12th release of the Assessment is serving as support for campaign claims by Al Gore to support his views on climate and energy use. Indeed, his release on environment and energy policy occurred just two weeks later on June 26th.