The Threat to the Planet
Jim Hansen, Director of the NASA Goddard Institute for Space Studies and Adjunct Professor of Earth and Environmental Sciences at Columbia University’s Earth Institute, has written three marvelous book reviews for The New York Review of Books.
“The Weather Makers : How Man Is Changing the Climate and What It Means for Life on Earth” by Tim Flannery
In the Earth’s history, during periods when average global temperatures increase by as much as ten degrees Fahrenheit, there have been several “mass extinctions, when between 50 and 90 percent of the species on Earth disappeared forever. In each case, life survived and new species developed over hundreds of thousands of years The most recent of these mass extinctions defines the boundary, 55 million years ago between the Paleocene and Eocene epochs. The evolutionary turmoil associated wit that climate change gave rise to a host of modern mammals, from rodents to primates which appear in fossil records for the first time in the early Eocene
If human beings follow a business-as-usual course, continuing to exploit fossil fuel resources without reducing carbon emissions or capturing and sequestering them before they warm the atmosphere, the eventual effects on climate and life may be comparable to those at the time of mass extinctions. Life will survive, but it will do so on a transformed planet. For all foreseeable human generations, it will be a far more desolate world than the one in which civilization developed and flourished during the past several thousand years.
“Field Notes from a Catastrophe” by Elizabeth Kolbert
As with the extinction of species, the disintegration of ice sheets is irreversible for practical purposes. Our children, grandchildren, and many more generations will bear the consequences of choices that we make in the next few years.
The level of the sea throughout the globe is a reflection primarily of changes in the volume of ice sheets and thus of changes of global temperature. When the planet cools, ice sheets grow on continents and the sea level falls. Conversely, when the Earth warms, ice melts and the sea level rises. In Field Notes from a Catastrophe, Elizabeth Kolbert reports on the work of researchers trying to understand the acceleration of melting…
Future rise in the sea level will depend, dramatically, on the increase in greenhouse gases, which will largely determine the amount of global warming.
The business-as-usual scenario yields an increase of about five degrees Fahrenheit of global warming during this century, while the alternative scenario yields an increase of less than two degrees Fahrenheit during the same period.
How much will sea level rise with five degrees of global warming? Here too, our best information comes from the Earth’s history. The last time that the Earth was five degrees warmer was three million years ago, when sea level was about eighty fee higher… Fifty million people in the US live below that sea level. Other places would fare worse. China would have 250 million displaced persons. Bangladesh would produce 120 million refugees, practically the entire nation. India would lose the land of 150 million people.
“An Inconvenient Truth” by Al Gore
Do we have politicians with the courage to explain to the public what is needed. Or may it be that such people are not electable, in view of the obstacles presented b television, campaign financing, and the opposition of energy companies and other special interests? That brings me to Al Gore’s book and movie of the same name: An Inconvenient Truth. Both are unconventional, based on a “slide show” that Gore has given more than one thousand times. They are filled with pictures—stunning illustrations, maps, graphs, brief explanations, and stories about people who have important parts in the global warming story or in Al Gore’s life. The movie seems to me powerful and the book complements it, adding useful explanations. It is hard to predict how this unusual presentation will be received by the public; but Gore has put together a coherent account of a complex topic that Americans desperately need to understand. The story is scientifically accurate and yet should be understandable to the public, a public that is less and less drawn to science.
The extracts I have lifted above don’t do justice to the analysis prepared by Dr Hansen. I urge you to read the full article, and indeed, read the books. — DS
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