They begin with a general explanation of the greenhouse effect, including the relevant gases in the atmosphere. Where the gases originate and the impact of each is covered. While there is debate as to the amount of carbon dioxide that should be allowed in the atmosphere, its reduction is essential.
The authors go through the evidence that the earth is warming. The effect is seen more in the higher latitudes (in Alaska the overall average temperature has risen 3.1 degrees F since the beginning of the twentieth century) than the tropical zones. Local effects will be variable. Each continent will have its own temperature curve because of other factors in addition to greenhouse gases. Eighty percent of earth's heat gain over the last fifty years has been stored in the oceans.
The impact of global warming is hard to predict. In general, wet regions will become wetter and dry regions dryer. Warm air can contain more water vapor (about 7% more for every 1.8 degrees F – 1 degree C) so there will be more rainfall globally. Undoubtedly there will be more flooding, caused by more extreme rainfall events. Sea levels will rise.
Desert areas are expected to increase in the American West, Australia, China, and Africa. In the past desertification was caused by human activity but climate change will also be a cause.
“There is considerable speculation over whether global change, especially the warming ocean, will lead to more frequent and more intense storms.” While North Atlantic hurricanes have increased in number and intensity over the last century, globally there has been no such trend.
The authors investigate the roots of the doubts cast on global change, identifying the major players. “Between 1998 and 2005 ExxonMobile gave almost $16 million dollars [sic] to anti-global warming advocacy organizations.” Koch Industries is another big spender, even outspending ExxonMobile. Other main sources of funding are pro-business and fossil fuel industries.
They note, “Among those who do research in any aspect of climate change there is essentially no controversy concerning whether global warming is upon us or whether humans are at least partly the cause of the problem. “...[T]he scientific debate is about details...”
Ice sheets are a major driver in the predicted rise in sea levels. “At present...the ice sheets are losing mass and melting at an ever-increasing rate.” Based on satellite observations, Greenland is loosing 247 billion metric tons of ice a year while West Antarctica is losing 120 billion metric tons. The Antarctic ice sheet in the east was seen to have a net loss for the first time in 2009. The melting of alpine glaciers is noted as well as shrinking ice caps in the Arctic. “Arctic lands are warming at five times the global average...” They report on the rising sea level as well as its acidification. Geoengineering, the large-scale manipulation of the environment, is investigated.
Each section has “myths” that are corrected. The authors have included an extensive bibliography.
“Global change is a certainty and the direction of change is well understood. But rates, volumes, and levels remain uncertain.”
Authors: Orrin Pilkey is the James B. Duke Professor Emeritus of Earth and Ocean Science at the Nichols School of the Environment at Duke University. Keith Pilkey is an attorney.
Artist: Mary Edna Fraser is a batik artist employing ancient fabric-dying techniques.
Duke University Press, 160 pages. Publisher information.
I received an egalley of this book from Duke University Press for the purpose of this review.