Book: Six Degrees: Our Future on a Hotter Planet

Author: Mark Lynas

Reviewed by: Michael Manely, CEO of The Manely Firm, P.C., International Family Law — a Global Atlanta sponsor

Michael Manely

It was the United Nations reports released in late November that caused me to revisit Six Degrees, a book that is now a decade old. When originally released in 2008, the UN’s Intergovernmental Panel on Climate Change had alerted us that the Earth would heat up by between 1.4 and 5.8 degrees Celsius by the end of this century. The new United Nations Emissions Gap report now predicts a 3.2 degree Celsius rise (5.8 degree Fahrenheit) by the end of the century, just 80 short years away.

Six Degrees is not a traditional global warming book. It does not offer remedies to ameliorate our destruction of the planet. Rather, Lynas analyzes the geological record to assess what happens on the Earth when it is 1 degree, 2 degrees, 3 degrees, etc., hotter than it has been during the Anthropocene era. It looks backward to examine what was, so that we can anticipate what will be.

To find out what the world looks like 3 degrees warmer, Lynas takes us back 3 million years to the Pliocene. Atmospheric concentrations of CO2 ranged from 360 to 400 parts per million. In 2008, concentrations were at 382 ppm. Today they are at 410.

In the Pliocene, continental glaciers were entirely absent form the Northern Hemisphere, contributing to a sea level that was 25 meters higher than today’s. The North Pole lost its ice sheet completely. Some 80 percent of the sea ice was gone. Both the poles and the tropics were much, much warmer. With an average temperature rise of 3 degrees, Europe would expect much drier winters and the Indian monsoons would cease, with billions of lives impacted by the lack of water. The Indus’ water supply would be reduced to 10 percent of its present output, the Ganges to 30 percent. In South America, the Amazon rain forest basin east of the Andes would rapidly become quite dry: “Modeled rainfall declines almost to zero in some areas by 2100,” Lynas writes. Average temperatures soar to Saharan highs, reaching on average 38 degrees Celsius (100.4 degrees Fahrenheit). El Niño would not only become stronger, it may become permanent.

According to Six Degrees, the drying of the African continent will be far off any scale that would permit human adaptation, bringing in a continent-wide famine. Some models predict Botswana being covered with active sand dunes.

Far more of Australia would burn. Days of temperatures above 35 degrees Celsius (95 degrees Fahrenheit) would increase from 100 to 600 percent in New South Wales while average rainfall there could fall by 25 percent. In Victoria, rainfall could reduced by as much as 40 percent. Only farms farthest south and nearest to the coast would remain viable in the coming decades.

In the United States, we should expect a 30 perfect reduction in rainfall along the West Coast.  Half of the year, the Colorado River system would fail to provide for the needs already allocated for human use. California, Arizona, Nevada, Utah, Colorado, New Mexico, Texas, Oklahoma and Kansas would experience permanent Dust Bowl devastation. New York City would be under water. Miami would be gone.

There is an upside for some areas: Norway would enjoy a growing season similar to southern England today. Finland would enjoy an increase of two months of its growing season.

At 3 degrees, the carbon cycle, where CO2 is stored in the Earth, reverses, spilling more gigatonnes of CO2 into the atmosphere, ramping up atmospheric concentrations by a further 250 ppm and giving a further 1.5-degree boost to global warming, rendering us a 5-degree world in very short order.

With all of this, a new report from the Breakthrough National Centre for Climate Restoration, an Australian think tank, contends that scientists are “vastly underestimating the impact climate change can and will have on our planet.” This report suggests that human civilization may come to an end as soon as 2050.

Whether we are at 3 degrees Celsius increase by 2100 or something even higher, we will have to go through one and two degrees to get there. And Six Degrees is an absolute must read for processing just how upended our lives could become each degree along the way.

Editor’s note: This review is part of Global Atlanta’s annual project asking influential readers and community leaders to review the most impactful book they read during the course of the year. This endeavor has continued each year since 2010. Purchases through the affiliate links at top will provide a commission to Global Atlanta. All books were chosen and reviews written independently, with only mild editing from our staff.