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Analysis has already reduced the implied impact of sea level rise. Similarly, the analysis in the Academy report of anticipated agricultural essects in the United States for the next fifty years or so shows a zero change in balance between fertilization induced by the increased CO2 and decreased rainfall. Refinements in the intervening years show no reason to change this conclusion. Concomitant analyses can and should be made for other regions of the world.

It is instructive, then, to bypass the complexities of both the climate and economic models by the following argument. We look back and accept the the rate of exponential growth of atmospheric CO2 for the last one hundred years as a given and use it to predict the future growth at the same rate. Since we know that the greenhouse effect of CO2 will increase only logarithmically with the concentration, we would expect an increase in global temperature in the next one hundred years of the same amount as for the last one hundred years namely 0.6 degrees centigrade, assuming that the temperature rise was indeed due to the rise in CO2. This is conservative reasoning but unfortunately tells us nothing of the regional climate changes. This also predicts something less than doubling of the CO2 concentration in that period.

There is no reason to believe that we are at the end of surprises in this very complicated set of phenomena. At this very time we are being exposed to two very radical concepts. The first is derived from the very recent measurements on the Greenland ice cores. This is a natural sequence to the researches on the Antarctic cores and the wealth of information that ensued. The Greenland cores are more informative because the greater precipitation yields time resolution of the order of one year. The extraordinary result, which is now widely disseminated, is that the earth's climate, as revealed by the cores, was extremely variable on nearly a year to year basis with abrupt changes in average temperature of the order of several degrees centigrade. This pattern abruptly ceased about ten thousand years ago and the temperature (and thus presumably the climate) has remained relatively quiet since. There are several implications or one can more properly speak of surmises. The one is that we are, and have been for several thousand years, in an abnormal climatic state. Another is that we are liable to leave this state and return to the more "normal" one of constant fluctuation at any tine. The weakness of this argument is that the reccord would only apply regionally, perhaps only to the North Atlantic. But then that also limits the geographical applicability of the temperature record.

The difficult part, if these observations hold up, is that our models give no indication of the existence of an earth with this kind of fluctuating climate. While there has been much talk and some examples of an earth with more than one "stable" climate, mostly in connection with attempts to explain the ice ages, they have not been very convincing The explanation may be straightforward and more comforting. This fluctuating behavior occurred during a period of glacier recession. There is no reason to believe that the glaciers receded uniformly and it is more likely that they alternated in receding from year to year. If so, Greenland would be subject to frequent reversals of winds that are symptomatic or causal of abrupt climate changes. Examination of the particles trapped in the cores may tell the story'.

Questions have also recently arisen in another area. That concerns the source of the rise in CO2 concentration as measured by Keeling. By ignoring the seemingly close correlation between the shape of the known CO2 emissions and the Keeling curve and starting ab initio, the startling conclusion can be reached that the anthropogenic component is only part of the rise and the remainder is due to shifts in the much larger natural reservoirs and fluxes. There is some debate swirling around this result but, if it too holds up, then the mitigation and adaptation issues change radically. The problem does not necessarily go away because the changes we may face are not man induced. They may become even more serious. It is one thing to plan mitigation against man's intervention into the environment. It is another to discuss mitigation against natural global climate change.

9 Lindzen, Richard, Private Communication, Sept.,1993

Chmate change is a fascinating and enjoyable topic when it is drawn away from policy and political considerations. The history of vineyards in Great Britain, the disappearance of Indian complexes in the United States Southwest, the abandonment of farming in the deserts in Peru and many other examples have induced great intellectual curiosity, research and entertainment. I feel that I should add a brand new one drawn from the observation that the earth bad a highly variable climate until about ten thousand years ago. This change coincides closely with man's development of an agricultural basis for existence. Until that time there is no archaeological evidence of any agricultural activity. Human life was that of hunting and gathering. We could surmise that only when the year to year climate remained reasonably stable in a given area that it became possible to experiment, to select and to draw reasonable return from the efforts.

November 7, 1994

Mr. ROHRABACHER. Just to let you know, and I respect each and every one of the panelists today, I mentioned earlier that I am a journalist by profession.

We were taught as journalists to put the most important item right up front. That is the lead of the story. Now in the academic world it is just the opposite, as you lead up to your most important point.

[Laughter.]

Mr. ROHRABACHER. When it comes to situations like this where we have about five minutes, I know how frustrating it must be to be trained in the academic profession and not be able to lead up to your point because, just as you get there, you have run out of time. So we will try to accommodate you, but if we could try to keep it as close to five minutes as possible so we can get some dialogue, and you can then actually expand upon your points.

Mr. NIERENBERG. Mr. Chairman, can I respond very briefly to that? I have a special problem. I understand that very well.

You see, several of the speakers now have spoken about hundreds, and even millennia, you see, in terms of this decay period. This is a very crucial policy issue, and I did not want to respond the same way just by saying it is 100 years and letting it go at that.

That is the crucial issue as far as you are concerned, you the Congress.

Mr. ROHRABACHER. Thank you, Doctor, we will be discussing that.

Mr. Gardiner?

STATEMENT OF DAVID GARDINER, ASSISTANT ADMINISTRATOR, OFFICE OF POLICY, PLANNING AND EVALUATION, U.S. ENVIRONMENTAL PROTECTION AGENCY

Mr. GARDINER. Thank you, Mr. Chairman, for the opportunity to be here to discuss the EPA report entitled The Probability of Sea Level Rise, which we released on October 27th, 1995.

This report provides estimates of the impact of climate change on coastline seal level elevations and is the first to attach not "predictions" but "probabilities" to different projections of sea level rise. This report builds on previous scientific studies, reconfirming the likely risk of sea level rise and reinforcing our concerns regarding the resulting environmental and economic impacts.

It also projects that global warming will worsen sea level rise significantly unless actions are taken to avoid it.

Let me say at the outset that we believe there is a strong scientific consensus on the following facts:

First, the sea is rising now, a trend that is confirmed by measurement data from the last 100 years.

Second, the sea will continue to rise over the next century and beyond.

Third, climate models are getting more accurate over time and are important for understanding future potential climate changes. Fourth, there is a growing scientific consensus that human-induced climate change is a reality.

And fifth, the uncertainties surrounding our projections of sea level rise are narrowing.

The EPA report is the product of sound science and increases our confidence in the estimates of sea level rise.

Now let me briefly summarize the reasons both why we did the report, the methods we used in developing the report, and the basic conclusions of the report.

First, EPA undertook this report because we are committed to doing the best possible science on issues that affect our environment.

Such research provides vital information to the public, decisionmakers, and other government agencies to assist them in doing the best possible job of managing our environmental resources.

Increasing sea level poses significant risks to our environment. Some of these effects are potentially catastrophic and irreversible. A sea level rise corresponding to the Intergovernmental Panel on Climate changes' latest best estimate, and EPA's 50 percent best estimate for the year 2100, could drown approximately 15 to 60 percent of our coastal wetlands, depending on whether they could migrate inland or whether levees and bulkheads block their migration.

Inundate more than 5,000 square miles, an area the size of Connecticut, of dry land in the United States if no protective actions are taken.

Areas at highest risk from sea level rise are areas currently experiencing rapid erosion rates and with very low geographic relief such as parts of the United States Atlantic and Gulf Coasts.

In addition, a large and growing proportion of the Nation's population, facilities, and development is or are being located along the

coasts.

Coastal development decisions are being made every day-decisions which are sensitive to sea level rise. Far-sighted policy making requires planning for the future to ensure that our efforts make economic and environmental sense.

That is what our report is all about. Helping coastal planners, engineers, and government agencies and the public carry out their responsibilities to protect the future of the coastal environment for the American public by providing them with information so that they can make better-informed, common-sense cost-effective decisions to protect coastal areas and structures, personal property, and coastal weapons in their particular communities.

Perhaps as important as why EPA did the report is how EPA did the report is how EPA did the report, and this, Mr. Chairman, gets at the question you were discussing with Mr. Guerrero at the end of the last panel.

Using existing models, including those from the IPCC, EPA conducted a study of the probable effects of global warming on sea level rise.

As part of a rigorous review process, reviews were sought and received from over 20 prominent members of the U.S. and international scientific community. I would indicate on the chart that is over here on the easel, the list of those 20 prominent scientists. I think their views represent a cross-section of the beliefs on the likely effects of climate change, as well as its impacts on sea level rise.

The agency went a step further and incorporated the reviewers' best estimates of the parameters most important to estimating the extent and probability of sea level rise.

We solicited expert opinions on a variety of key factors. All of the estimates, from skeptics to supporters of global climate change and sea level rise were used and were given equal weight in deriving the results of this study.

The reviews also supported the statistical viability and universal acceptance of the quantitative methods used in the study.

[Chart.]

I would also note that a paper by the authors will shortly be published as a distinguished scientific journal.

Finally, the results:

The EPA report estimates, and what we believe to be the best estimate, is that of the 50 percent chance of sea level rising 18 inches or 45 centimeters by the year 2100, with more than twothirds of that increase attributable to a warming in the Earth's atmosphere.

The EPA report attaches probabilities of 10 percent and 1 percent, respectively, to its estimates on the 29 and 44 inch rise by 2100.

We estimate a 90 percent change of an 8-inch rise.

Estimates of sea level rise vary substantially by locality due to local coastal conditions, and if we can-actually, it is the next chart-for example, by 2100 there is again a 50 percent change that the sea will rise 13 inches in Los Angeles, 20 inches in Miami Beach, 22 inches in Boston, 27 inches in Atlantic City, 38 inches in Galveston, 55 inches in Grand Isle, Louisiana. [Chart 2]

I would like to note the agreement and general consistency between the EPA and IPCC sea level rise estimates.

Again, if we look at the next chart, we can see that there is substantial consistency between the best estimate by the IPCC which projects a 19-inch increase by the year 2100, very close to EPA's estimate of 18 inches. [Chart 3]

We are in close agreement with IPCC's low estimate of an 8-inch rise for which we estimate a high likelihood probability of 90 percent. I will conclude shortly.

In summary, the probability of sea level rise is an example of EPA's commitment to sound science. I am confident that this study adds substantially to the scientific literature on sea level rise and breaks new ground in making available realistic and useful estimates of the probability of sea level rise to decision makers, scientists, and the public.

Ultimately this report will help decision makers make common sense, cost-effective decisions to protect our coastal areas.

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