Well, the sulfate argument probably does not work. And it is doubtless that those satellite temperatures are correct. This record here shows the satellite temperature record, in this shaded area here that is flat, the open circles are weather balloon records from 5,000 to 30,000 feet, and the closed circles are ground-base temperatures. The ground-base records are going up. The atmosphere is not warming above 5,000 feet. Every climate model that we have, and this is typical of them, I will go back, predicts a warming in the range of 0.23 degrees celsius per decade in the entire atmosphere, all the way up to the stratosphere. From the surface all the way to the tropopause, an average of 45,000 feet, to be warming that much. These are the warmings that are occurring between 5,000 and 30,000 feet, depending upon what record you use. This is a typical computer model-and I am just about to endthis one from the Lawrence Livermore National Laboratory. This is north, this is south. Everywhere where it is orange or yellow it is predicted to have warmed in the last 25 years and then it cools in the stratosphere. There is no warming in the last 25 years in all the records that we can find in that zone. Now, I am going to turn the tables here and close with what I want to call reverse argument. Let's say that all that money that we have spent on climate change has bought us something; I do not know what, but let us say it has bought us the fact that we know the way the climate changes once it starts to change. This is a series of outputs from various computer models. I would like to draw to your attention that once the planet starts warming, it warms at the same rate that it began to warm. It warms at a constant rate. It does not warm at an increasing exponential rate. There are various assumptions in these models; some of them have sulfates in them, some of them do not, some of them have the real way that CO2 is changing in the atmosphere, which is the low one down here, others do not, and we have nature since 1968 warming up the surface temperatures of our planet. I believe nature has already given us the answer on global warming. There is the trend of the last third of this century extended out under the assumptions that all the climate models make, that the warming is a straight line. It works out to 1.3 degrees celsius over the course of the next 100 years. Because of the winter-summer differential, it is about 1.5 degrees in the winter, 1.1 degrees in the summer. Hard to call that a pollutant. Thank you very much. [The prepared statement of Mr. Michaels follows:] Testimony of Patrick J. Michaels, Professor of Environmental Sciences, University of Virginia, and Senior Fellow in Environmental Studies at Cato Institute, to the Subcommittee on National Economic Growth, Natural Resources and Regulatory Affairs, U.S. House of Representatives, October 6, 1999. Thank you for soliciting my testimony on the nature of Carbon Dioxide as a "pollutant" with regard to global climate change. I regard a "pollutant" as something that produces a demonstrable net negative impact on climate and ecosystems. "Negative" and "positive" impacts on climate are value judgements made by human beings. Within that limitation, I submit the following: This testimony demonstrates that the observed climate changes that have accompanied the enhancement of the natural greenhouse effect have been considerably smaller than they were originally forecast to be, and that they are likely to remain similarly small. Further, they are inordinately confined into the winter, rather than the summer, and, within the winters, they are inordinately confined to the coldest, deadliest airmasses. There is no overall statistically significant warming in the average temperature of the United States, which is a record of 105 years in length. While the United Nations has stated that during the greenhouse enhancement, "the balance of evidence suggests a discernible human influence on global climate," I cannot view what has happened as a net negative; some might easily argue that it is a net benefit. Under neither interpretation does this qualify carbon dioxide as a climatic "pollutant." In January, 1989, over ten years ago, I first testified on climate change in this House. I argued that the computerized climate models from that era were dramatically overpredicting future warming, and that the observed history of climate projected a much more moderate warming, of 1.0° C to 1.5° C, over the next century. I further argued that it would eventually be recognized that this moderate climate change would be inordinately expressed in the winter vs. the summer, in the night vs. the day, and that overall it was plausible to argue that these changes conferred a net benefit upon our world. If I had the perfect vision of knowing what would have happened to the climate in the next ten years, how the scientific literature evolved—in its attempts to explain the lack of warming, and in its refusal to recognize persistent, damaging and pervasive errors in the forecast that continue to this date--I would have changed not one word. This testimony explains why. In the last ten years, we have learned that: • Observed surface warming is most consistent with a forecast below lowest statistical range forecast by climate models. Recent observed changes are several times beneath what was forecast a mere ten years ago, assuming historical changes in carbon dioxide (see Hansen, et al., 1998). • The postwar ratio of winter-to-summer warming is greater than two-to-one (Balling et al., 1998) • Over three-quarters of the cold half-year warming in the Northern Hemisphere is confined to the very coldest airmasses. The warming outside of these airmasses is a minuscule 0.2° C per century (Michaels et al., 1999). • The variation, or unpredictability, of regional temperatures has declined significantly on a global basis while there is no change for precipitation (Michaels et al., 1998). • In the United States, streamflow records show that drought bas decreased while flooding has not increased. (Lins and Slack, 1999), • Maximum winds in hurricanes that affect the United States has significantly declined (IPCC, 1995), and there is no evidence for a global increase in damaging storms (Landsea et al.,1996). The Kyoto Protocol to the United Nations Framework Convention on Climate Change will have no discernable impact on global climate within any reasonable policy timeframe (Wigley, 1998). In toto, these findings lead inescapably to the conclusion Carbon Dioxide is not a "pollutant," and plausibly argue that it is a net benefit. Scientific Background It has been known since 1872 that water vapor and carbon dioxide are the principal "greenhouse" gases in the atmosphere, and that increasing their concentration should elevate the temperature in the lower atmosphere. What has been a subject of contention ever since, is the amount and character of the warming. Because of all of the atmospheric greenhouse gases emitted by human activity, we have progressed to roughly a 60% increase in the equivalent natural carbon dioxide greenhouse effect. The earliest climate projections, made by Arrhenius in 1896, indicated this would result in a rise in mean global temperature of approximately 3.25°C. Computer models that served as the basis first Scientific Assessment of Climate Change by the United Nations Intergovernmental Panel on Climate Change were around 1.8°C for current greenhouse changes (Murphy and Mitchell, 1995). These were lower than original estimates largely because of the retardation of direct warming by the ocean. The 1.8°C figure was typical of the range of most climate models, and led to the scientific bifurcation between the modelling community and the more data-driven empiricists, who argued that the observed 20th century warming of 0.6°C (with half of that before the major greenhouse gas changes) indicated future warming would be around one-third of the mean projected value of 4.2°C over the next century, or around 1.0 to 1.5°C. The IPCC admitted the validity of this position in its 1995 report, when it wrote that: "When increases in greenhouse gases only are taken into account...most [climate models] produce a greater mean warming than has been observed to date, unless a lower climate sensitivity [to the greenhouse effect] is used...There is growing evidence that increases in sulfate aerosols are partially counteracting the [warming] due to increases in greenhouse gases." Are sulfate aerosols responsible for the now-admitted dearth of warming? In previous testimony I have shown how poorly this argument stands the critical test of the data. Suffice it to say that the record of the three dimensional atmospheric temperature in recent decades does not appear at all consistent with this hypothesis. Instead of repeating that argument, I would simply point out that the southern half of the planet is virtually devoid of sulfates, and should have warmed at a prodigious and consistent rate for the last two decades. Unfortunately, we have very few longterm weather records from that half of the planet, and almost all come from the relatively uncommon landmasses. However, we do have over two decades of satellite data (Figure 1), adjusted by John Christy for orbital decay and other drifts; it shows no change in temperature whatsoever, although the prominent spike and retreat from the 1998 El Nino is rather striking. Figure 1. Southern Hemisphere MSU satellite temperatures, drift-adjusted, from John Christy of University of Alabama, 1/1/79-8/31/99. The sulfate hypothesis implies this zone should be warming rapidly. The failure of the climate models is much more profound than any error that could simply be corrected by reducing the amount of incoming surface radiation, which is what the sulfate "fix" does. Instead, it is a failure in the vertical dimension that has been occurring for nearly a quartercentury. Figure 2 shows the entire concurrency for our three records of "global" temperature, which is limited by the beginning of the satellite MSU data in January 1, 1979. The record is now completing its 21st year. Our figure shows satellite temperatures, weather balloon temperatures roughly between 5,000 and 30,000 feet, and surface temperatures measured by thermometers. There is an increase in the surface record of 0.15° C/decade. Research by NASA scientist demonstrates that about 0.02° C/decade of this is a result of changes in the sun (Lean and Rind, 1998), leaving a remaining 0.13° C/decade ascribable to human influence or other natural variation. The other two records show no change. The disparity between the surface, satellite and weather balloon readings is likely to have some basis in reality. The concordance between the satellites and balloons cannot be from chance, so there must be some process occurring in the lowest layers (below 5,000 feet) that is not being picked up in those two records. Annual Global Temperature Departures (1999 value based on 8 month mean) 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 |