Many of the long-term consequences of global warming have already begun and are in front of our eyes. The real world examples listed below illustrate that fact. Melting Arctic sea ice.[1] Melting ice shelves in Antarctica . Melting glaciers in Greenland, Glacier National Park , on Mt. Kilimanjaro , the Alps, Nepal/Tibet, and throughout South America . Increased icequakes in ice caps and ice sheets around the world indicating accelerated movement. Poleward migration of climate belts and flora and fauna. Gradual decline or disappearance of numerous species including polar bears, Edith’s checkerspot butterfly, Adele penguins, polar sea birds, and numerous frogs, toads, and lizards. Melting of Siberian permafrost and previously frozen peat bogs and subsequent release of both CO2 and methane. The most intensive infestation of spruce bark beetle in Alaska ’s Kenai Peninsula , affecting approximately 1.1 million acres and killing tens of millions of mature spruce trees. And the infestation of millions of acres of Canadian forests by mountain pine beetles in what the Canadian Forest Service calls the largest known insect infestation in North American history. All of those effects are happening today and will continue into the foreseeable future as other yet undetected effects will be found.
But what if the world could get its act together and change the existing conditions where CO2 and other heat-absorbing atmospheric gases are injected into the air seemingly without thought of consequence? Would there be sufficient time to get those emissions in control and avoid the worst potential consequences? The answer is a tentative affirmative, not because the technologies are unavailable but because of the lack of political will, especially in the U.S. James E. Hansen, Director of NASA’s Goddard Institute for Space Studies and Adjunct Professor (PhD Physics) of Earth and Environmental Sciences at Columbia University’s Earth Institute, believes that we have ten years (starting from 2005-2006) to enact national and international policies and procedures to control those harmful emissions. He doesn’t mean we have ten years to think about doing something but ten years of focused action before climate change starts turning ugly. As Hansen wrote in an essay on November 28, 2007:
Ignorance is no excuse for us. There is overwhelming scientific evidence of global warming, its causes, and many of its implications. Today’s generations will be accountable, and how tall we stand remains to be determined. There is still time, but just barely.[2]
So, given the political malaise that currently grips Washington , DC
According to most atmospheric scientists, continuation of the status quo will result in doubling the current rate of poleward movement of climatic isotherms (temperature lines used to mark the boundaries of climate types) to about 70 miles per decade. Several centuries of that movement will result in the extinction of between 40 and 60 percent of the species on Earth and will transform the Great Plains, Southeast, Midwest, and perhaps the Mid-Atlantic states into arid and semi-arid regions, eviscerating the heart and soul of agricultural America
That rise would inundate every coastal city in the world and every low-lying island, displacing perhaps a billion people and drastically altering the socioeconomic web of modern civilization. Under that scenario, it is conceivable that by around 2200 sea levels will have risen as high as 20 feet. And as peak summer temperatures rise, the resulting heat waves in individual countries could push the annual number of heat-related illnesses and deaths to the hundreds of thousands, especially in light of the record heat wave that devastated Europe in August 2003, killing an estimated 35,000 people. Note that that number may actually be lower than the grim reality since several European governments were very reluctant to reveal publicly systemic failures in their national healthcare delivery programs.
Implementation of the contra-global warming alternative scenario is anticipated to yield a global average increase of less than two degrees Fahrenheit during the same 50-year period and would result in a significant rise in the sea level, probably on the order of 14 to 17 inches by 2100 or even slightly higher. But the slower rate of temperature increase would allow time to develop and put in place policies, regulations, strategies, new technologies, and mitigation measures that would enable communities to adapt to the rise in temperature and sea level. Despite the lower rate of increase of harmful atmospheric gases, it is estimated that this alternative scenario will lead to the eventual extinction of 20 percent of species alive today and the degradation of significant land and water habitats.
But the simple truth is that even the worst case global warming will not radically affect the Earth and most lifeforms. Of course, many species would perish under the status quo scenario. But the mass extinctions that happened many times in the geological past were followed by large-scale biological radiations, such as the radiation that was responsible for the rapid rise of mammals. Therefore, a short-term climate change (in the geological sense) is not likely to spell doom for the Earth. Actually, a hotter, more humid planet would be ideal for most life and would favor quite a few species. Biological organisms are fundamentally much more resilient than humans and more adaptive to widespread environmental change than the modern civilization we have created, with such complex socioeconomic entities as cities, states, as well as local, regional, national, and international market systems. Keep in mind that even polar bears managed to survive a significant climate change that occurred about 120,000 years ago that increased the Earth’s average temperature by several degrees over what is found at present. So, although the news is not uniformly bad, the adverse effects of global warming on people and the institutions and organizations we have created will be highly significant and probably unavoidable and may prove catastrophic, especially for the many millions of people who live in coastal or island environments or those who depend on glaciers as sources of potable and agricultural water.
The big question concerns which of those scenarios will play out. Although at this point no one knows, several indicators may be identified. First, awareness of the threats of global warming characterizes about half of the general public, though that doesn’t mean that appropriate actions are close at hand. Second, well-known and wealthy individuals and foundations are using their clout and money to make a difference in the movement to control the warming trend.
On the other hand, large coal-fired electrical generating plants using current technology are being planned and permitted in several states; those plants do not employ the latest and most efficient anti-pollution designs and will therefore generate more pollution over their projected 30-year lifespans than if the cleaner and more advanced Integrated Gasification Combined Cycle coal technology (IGCC) had been used. Even today, the State of Texas , with its large supply of current technology coal-fired power plants, leads all U.S.
[1] The largest summer retreat of Arctic sea ice ever measured was in 2007 with 2008, 2009, and 2010 having recorded the second, fourth, and third lowest levels.
[2] James Hansen: "Averting Our Eyes,” http://gristmill.grist.org/story/2007/11/28/215831/00; the essay can and also be found at: http://dotearth.blogs.nytimes.com/2007/11/28/averting-our-eyes-james-hansens-new-call-for-climate-action/
[3] These scenarios were first developed and presented by James Hansen in New York Review of Books; Volume 53, Number 12, July 13, 2006.
[4] Three million years ago, when global temperatures were slightly greater than five degrees higher than they are today, sea level was about 80 feet higher than at present. However, it is likely that it would take several centuries for that eventual rise to be completed.
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