What's up with global warming?

Before Mitt Romney became the nominee apparent, several Republican candidates enthusiastically denied anthropogenic climate change (the terminologically correct expression for what most people mean when they say "global warming").That controversial topic has faded in the light of jockeying between GOP candidate and Democratic incumbent on issues of healthcare, the economy, and governmental ideology. Yet Bill McKibben just wrote an incendiary article for the August 2 issue of Rolling Stone magazine in which he spells out the significance of three numbers which he argues signify a much bleaker picture for the future of human civilization than previous arguments on the ramifications of global warming. Before we outline his arguments, a little background on Bill McKibben, who is known for a different number, as the founder and primary spokesman for 350.org. McKibben is a Harvard educated journalist and author, formerly with The New Yorker, who penned one of the first books for a general audience on climate change in 1989. He founded 350.org to give a grassroots voice to "solving the climate crisis," as the website states. "350" signifies the number in parts per million of CO2 in the atmosphere. Many scientists believe that 350 ppm of atmospheric CO2 is the long-term upper limit for human habitability on the planet. Throughout accessible climate history, going back as far as 650,000 years, as measured in part by polar ice core samples, the average CO2 content in the atmosphere has been consistently in the range of 275-280 ppm. Beginning in the 18th century, with the advent of fossil fuels, that number began to rise. It currently stands at about 396 ppm, as continually measured at the Mauna Loa Observatory in Hawaii since 1958 (currently increasing at the rate of about 2 ppm per year). While the Rolling Stone article begins with the reminder that the month of June "broke or tied 3,215 high-temperature records across the United States," McKibben's new numbers reinforce his dark forecast. The first number, 2º Celsius (about 3.6 degrees Fahrenheit), is another view of the upper limits to habitable global warming as agreed on by all international conferences on the topic dating back to 1995. As McKibben puts it, "The official position of planet Earth at the moment is that we can't raise the temperature more than two degrees Celsius--it's become the bottomest of bottom lines." More specifically, McKibben describes the current situation this way: "So far, we've raised the average temperature of the planet just under 0.8 degrees Celsius, and that has caused far more damage than most scientists expected. (A third of summer sea ice in the Arctic is gone, the oceans are 30 percent more acidic, and since warm air holds more water vapor than cold, the atmosphere over the oceans is a shocking five percent wetter, loading the dice for devastating floods.)" The second number is 565 gigatons (A gigaton is one billion tons.) Again, McKibben states, "Scientists estimate that humans can pour roughly 565 more gigatons of carbon dioxide into the atmosphere by midcentury and still have some reasonable hope of staying below two degrees." Third on McKibben's list is the number 2,795 gigatons. This, according to the Carbon Tracker Initiative, an ongoing London investment analysis, is "the amount of carbon already contained in the proven coal and oil and gas reserves of the fossil-fuel companies, and the countries . . . that act like fossil-fuel companies. In short, it's the fossil fuel we're currently planning to burn. And the key point is that this new number--2,795--is higher than 565. Five times higher. "We have five times as much oil and coal and gas on the books as climate scientists think is safe to burn. We'd have to keep 80 percent of those reserves locked away underground to avoid that fate. Before we knew those numbers, our fate had been likely. Now, barring some massive intervention, it seems certain." With such a somber prediction, surely there must be a dissenting opinion. We will examine one such assessment next week.

********** Published: July 26, 2012 - Volume 11 - Issue 15