Monday, March 29, 2010

The Two-Degree Fable

The Safety of a Two-degree Tipping Point is a Political Dream

The dream is that we can with safety and confidence allow the average temperature of the earth to rise by two degrees C above the long-term mean. The hypothesis is that (1) we can stop there; and (2) that the changes in the earth will be tolerable, if not minor. I do not know where the two-degree hypothesis was invented but it is a political wish and has no basis at all in biophysical reality.

To think about the issue realistically one must realize that solar energy is received differentially by the earth with the greatest intensity in the tropics and the least in the polar regions. In the tropics most of the energy that is absorbed and not reflected back into space is dissipated into the atmosphere in the latent heat of vaporization: it is absorbed in the evaporation of water, which is abundant in the tropics, and the tropics are not warmed greatly as the heat-trapping gases accumulate in the global atmosphere. The moisture vapor enters the normal circulation patterns of the atmosphere and is carried to the higher latitudes and to higher elevations. Cooled, the vapor condenses and produces rain. In condensing the latent heat of vaporization is released and the region is warmed.

The warming is especially great in the mid- and higher latitudes, 45 degrees north and above. In the northern hemisphere there is much land at these latitudes with much forest and tundra with large stores of carbon in plants, soil and in the peat deposits of the tundra. The change in temperature in these regions is two to four times the average for the earth as a whole. That rise in temperature is confirmed in various ways not the least of which is the melting of the sea ice of the Arctic Ocean now at its lowest level in history.

The result on land is already apparent in the increased frequency of fires and insect damage in the largest forested region in the world, the boreal forest of North America, Europe and Asia. It also appears in the north as the melting of once-permanently frozen ground and the release of carbon as carbon dioxide and methane from such soils and from the accelerated decay of tundra peat.

These transitions in the northern regions are all in the direction of releasing additional carbon from large carbon reservoirs into the atmosphere: positive feedbacks, factors that make the problem worse. Stopping a warming, once underway, becomes increasingly difficult. The assumption that a warming that reaches an average for the earth as a whole of 2 degrees with 6 or more degrees in some sections of the high latitudes is either safe or potentially reversible is a very large and risky assumption, almost certainly incorrect. Taking that risk is little short of foolhardy.

The time to experiment with easy or painless transitions to a carbon-free energy system was forty years past when it became clear that the world was headed for severe climatic disruption. Safety now lies in an abrupt change, an overt abandonment of fossil fuels as the primary energy source for industrialization. We can meet the requirements of the agreement signed and universally ratified in 1992 to stabilize the heat-trapping gas content of the atmosphere substantially immediately and then move to reduce it over the next decades.

The alternative is the potential for an environmental, political, and economic chaos whose seeds are being planted at the moment as persistent devastating droughts on all continents including Australia.

George M. Woodwell, Founder and Director Emeritus
The Woods Hole Research Center
P.O.Box 296
Woods Hole, Massachusetts 02543

C 508 566 1838
W 508 444 1504

Thursday, March 25, 2010

Haiti and The Nature of a House

March 25, 2010
Building a World that Works

Scientists like to gain perspective by pushing trends to the extreme to see the full dimensions of any issue. I have dealt throughout my life with various aspects of biotic impoverishment, causes and extent, and what I thought might be extremes, even end-points. I have dealt personally as an ecologist with agriculture, grazing, forest harvests, toxic substances, chronic mechanical disturbances, effects of ionizing radiation, effects of nuclear weapons, even "nuclear winter", and climatic disruption. In each instance I have looked at extremes, seeking insights as to how to avoid them by early action.

The experience was critical as I began writing about the new campus of the Woods Hole Research Center, where my ecologist colleagues and I tried to bring together the principles we develop in science and to apply them in building a campus as an inspirational example for the new century as we move past the fossil fueled age. To emphasize the imporance of making that transition I sought an example of  the endpoint of current trends, where we are headed if we fail to make the change?  Haiti stands as the singularly most powerful example of a failed nation  in the western world. It is in political, economic, and environmental chaos and has been there, sinking decade by decade into greater depths of poverty through two centuries. There, the honors paid to growth in population and the free market system, led, not to economic nirvana, but to a poverty so severe that here was no hope of recovery without a massive infusion of money and plan from outside the country.  Without a working, functional landscape, capable of supplying essential needs such as a reliable water supply, no governement and no economy could stand.

That was all before the earthquake of January, 2010 when Haiti’s miseries were compounded a hundred fold, almost beyond comprehension. And they are not over. Before the earthquake Haiti was in dire trouble and should have had the attention and  extraordinary interest and support of all the western nations to restore a landscape, once a tropical dreamland, now barely more than  a  gravel pile at the mercy of  tropical rains. It could, and should, have been a model for the restoration for the world. Now that  objective is only more acute, but buried in the continuing emergency of ten million people trying to live on ten thousand square miles of largely mountainous land, virtually totally deforested, eroding and crowded with habitations, many now in ruins.

Haiti must be rescued. It must be rescued immediately from the devastation of January with massive gifts of food and housing, schools and public services. But in the only slightly longer term it must be reconstituted as a functional landscape, capable of supporting a finite population, yet to be determined, indefinitely.

I referred in the book to the Haitian Abyss, an example awaiting an unsuspecting world. The earthquake has brought the seriousness of the Haitian example home to all. We owe it to ourselves, and to the world, to take the example as a lesson and by common will restore that nation to prosperity with an environment that works in support of all, a wholesome and attractive example, a complement to a world in transition to the post-fossil fuel age. It will take imagination, and billions of dollars.  But the big new point is that the first steps must be the reconstitution of a functional landscape capable of supporting both an economy and a government. Civilization requires all three.  And recovery from the Haitian Abyss will take a monster effort, much money, and years of attention from a coalition of  governments, all of whom will benefit from the experience of rebuilding  Haiti.  It will be tough work but a far, far better investment than war.

Woods Hole, MA

* G.M. Woodwell. The Nature of a House: Building a World that Works. Island Press. 2009