Dr. Hansen (Director, NASA Institute for Space Studies Professor of Earth and Environmental Sciences, Columbia University) visited Washington DC Monday, February 26, 2007 to give a lecture on Climate Change at the National Press Club and American University. Author of, Dangerous Human Made Interference With Climate, his speech “Global Warming: Connecting the Dots from Causes to Solutions” delivered fascinating information about the state of our planet’s climate. Here are the main points of the speech, check it out.
The main points are:
A. Climate Sensitivity: What can be called the “Charney” or “fast feedback” climate sensitivity is now well-established: it is approximately 3C for doubled CO2 (forcing of 4 W/m2). However, some of the “boundary forcings” in this “Charney” definition are themselves variables or slow feedbacks. Indeed, the boundary forcings (surface albedo and long-lived GHGs) that are the principal mechanisms for climate change on the 100 ky time scales are in fact feedbacks on those time scales. The problem for humanity is that some of these “slow” feedbacks are not so slow – they may experience significant change this century and increase the climate response beyond that which is calculated by the typical model used in IPCC simulations. [Vegetation feedback – forests and shrubs are moving poleward, into regions that were tundra. Ice sheets are getting darker (wet) and before the century is out they could get smaller. Long-lived GHGs may provide a positive feedback, as in paleo experience, e.g., from methane hydrates.] So the effective climate sensitivity on the century and longer time scales is greater than the Charney sensitivity. We will begin to notice these additional feedbacks now, as we have entered the period of significant almost-monotonic global warming with isotherms moving poleward.
B. Dangerous Level. We do not know what long-term level of CO2 constitutes “dangerous human-made interference” (the level can be raised somewhat if we reduce other GHGs such as CH4), but it has become clear that it is not greater than about 450 ppm, and may be considerably lower. Given the fact that at least ~ one-quarter of fossil fuel CO2 emissions remains in the air “forever” (more than 500 years), and given the magnitude of the oil, gas, coal and unconventional fossil fuel reservoirs, it is follows that readily available oil and gas are going to take atmospheric CO2 to at least ~450 ppm. Thus even with responsible efforts to slow emissions, it is likely that atmospheric CO2 amounts will exceed the dangerous level, and we will need to find ways counteract the warming effect of these GHGs.
C. Responsibility. Despite the fact that China will soon exceed the U.S. in current CO2 emissions, the U.S. will continue to be primarily responsible for the human-caused climate change for many decades into the future. So, unless we begin to act responsibly, we will leave a tremendous moral burden, and perhaps a legal burden, for our children and grandchildren (and ourselves: some effects are going to be obvious soon enough). There is still time to keep GHGs at approximately or reasonably close to the “dangerous” boundary, but only if we get on a fundamentally different energy track within a decade, which requires that we begin to move “now”. If we do not stay within or close to that boundary, actions to avert irreversible effects (species extinctions, ice sheet disintegration/sea level rise) are not likely to be effective.
D. Geoengineering. I doubt the feasibility/desirability of geo-engineering suggestions such as the human volcano or space mirrors. If it proves necessary to counteract past emissions, why not a more “natural” method of drawing CO2 out of the atmosphere: negative-CO2 power plants that burn biofuels (derived, e.g., from cellulostic plants)? I like this partly because it has red states coming to the rescue of (mostly coastal) blue states*, and it will be a boon to red states and farmers. CO2 can be fail-safe sequestered under ocean sediments, where it is stable, in effect putting it back where it came from. *By the way, there are white states – I live in one (Pennsylvania) and grew up in one (Iowa), (others: Minnesota, Wisconsin…) – our vote counts.
E. Other Recommendations.
(1) Moratorium on building coal-fired power plants until they include sequestration. The public needs to enforce this temporarily until the people we elect are able to do the job. Excessive worry about power plants in other countries is unwarranted: these countries will soon begin to be realize that all old-technology coal-fired power plants eventually must be bulldozed.
(2) There must be a gradually rising price on carbon emissions and it must be complemented by increased technology investment, so that consumers have choices that allow them to reduce their carbon needs. Continued rise in the carbon tax must be certain, so businesses will invest and spur innovation. Positive long-term impacts on the economy, balance of payments, energy independence, national security… Presently the government provides only chicken feed for technology development, except for coal and nuclear power. I hope that government leaders who stand in front of renewable energy facilities, trying to claim credit, do not fool the public.
(3) Incentives (carbon price) have to be complemented with energy efficiency standards. There is enough potential in efficiency to take care of increased energy needs over the next decade and more, if the government gets behind efficiency standards. Instead our government is idiotically standing in court with those who resist standards for the sake of short-term profits. (Does this have anything to do with special interests and recommendation #5 below?). Structural barriers that inhibit efficiency (e.g., regulations that result in power companies making more money if they sell more electricity, rather then if they help reduce requirements) need to be addressed.
(4) Congress should ask the National Academy of Sciences to do a prompt study on the stability of ice sheets. This topic is, I believe, the prime driver of what constitutes a “dangerous” GHG level. The matter is too urgent to wait for the necessarily slow IPCC process. A study of this sort avoids the pressures for “scientific reticence” that can affect individuals. The Academy was established by Abraham Lincoln for purposes such as this.
(5) Public Affairs offices at the science agency headquarters should be staffed by non-political professionals. A democracy is based on the premise that the public is informed, honestly informed. What would our Founding Fathers think of the Offices of Propaganda that our executive branch has installed in these agencies? Is the public even aware that when a government scientist testifies to Congress his testimony must be approved and edited by the White House? Where does the authority for this come from? Is Congress ceding authority to a unitary executive? Is this the way our democracy was intended to work?
The greatest obstacle to solving the climate crisis is the “special interests”. As long as the coffers of our elected representatives can be filled by special interests, the latter will keep calling the tunes. Until there is true campaign finance reform, the special interests will continue to make a mockery of the central proposition of our democracy, that the commonest of men should have a vote equal in weight to that of the richest, most powerful citizen.
Finally, you might look into the activity at www.stepitup07.org organized by Bill McKibben. In coordination with Earth Day Network, they are planning nationwide rallies on April 14.
To view the charts and graphs from the presentation go to the link below:
http://www.columbia.edu/~jeh1/dots_feb2007.ppt
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