Global Warming may be accelerating much more rapidly than scientists recently thought. By mid-century the results may be catastrophic, not simply "inconvenient." There are indications of a doubling of the predicted 2°C rise in temperature by 2100.
A peer reviewed study published in Nature predicted that by the end of the century the average global temperature will have risen by 4°C (7.2°F), resulting in much of the tropics of today becoming uninhabitable. Their research, also reported in the Huffington Post, was based on an evaluation of cloud cover, which reflects sunlight (and direct solar heat) back into space. Their conclusion is that a decline in cloud cover is occurring, allowing more sunlight heating to reach the surface, and to be retained there by the excess carbon dioxide in the atmosphere. As the process proceeds, the rate of cloud cover decrease increases, causing a spiraling heating of the planet. The result "would guarantee the eventual melting of the Greenland ice sheet and some of the Antarctic ice sheet." Of course, ice sheets on Greenland and at both poles are melting already.
Arctic sea ice, showed an increase in volume of about 50 percent at the end of summer 2013 from 6,000 cubic kilometers at end of summer 2012 to 9,000 cubic kilometers at end of summer 2013. Global warming deniers have made much of this as a demonstration of the end of global warming, but no such luck. The summer extent of Arctic ice volume remains in a downward slide with occasional upticks from a 1980 summer volume of 20,000+ cubic kilometers.
There will be a regular summer passage through the Arctic Ocean by mid-century. There is a definite likelihood of there being at least an intermittent open summer passage within less than 10 years, an outcome predicted less than 5 years ago to occur near the end of the century.
So much Antarctic continental ice has melted that significant weight has been removed from the softer bedrock of West Antarctica. The harder rock of East Antarctica is shoving the softer de-weighted West Antarctica side of the continental mantle to the side at a rate of about a half-inch per year. Meanwhile, global warming deniers have touted the supposed irony of 50+ scientists, including some climate scientists being stranded on a ship stuck in Antarctic Ice in the middle of Antarctic summer.
While the juxtaposition of climate scientists stuck in the ice in summer may be worth a small dry chuckle, there is no real irony here, unless it be the ignorance the deniers display in their attempts to discredit (not disprove) man-made global warming. All absurdity aside, the ship is stuck in sea ice (not a great surprise – it's a ship), and sea ice formation is more a function of cold air blowing off the ice-covered continent and freezing the surrounding water than anything else.
Papers presented at the American Geophysical Union's annual conference in San Francisco in early-December presented evidence that Arctic warming, which is accelerating 2 to 3 times more rapidly than overall Global Warming, has resulted in "methane fountains" bubbling up through the Arctic Ocean. The papers also make it clear that Arctic warming will thaw the permafrost, allowing the release of gigatons of methane. Methane is a greenhouse gas 20 times more potent than carbon dioxide. The effects of methane are not taken into account in the Nature study of declining cloud cover, but it's not much of a logical leap to see a frightening synergistic effect once Arctic methane is carried into the general atmosphere.
It's time to make something clear. It is not only IPCC climate scientists who agree that humans have created a nearly 50 percent increase in atmospheric CO2, the primary driver of global warming to date. Geologists, paleobiologists, oceanologists, and several related disciplines all have contributed papers and studies to various journals that are used as the bases for the news reports identified in this report. As a final example, the publication Climate Progress offers an analysis by several disciplines of NASA 2013 September data.
The conclusion is that September 2013 is the warmest September in the past 11,000 years, although it should have been cooler because there was no el niño, the Pacific Ocean is much warmer than it should be, and its temperature increased much more rapidly than was expected, because the oceans have been acting as heat sinks for atmospheric heat. Further, the Arctic is warmer than it has been in as many as 120,000 years.
The following declarations are declarations of fact. The physics of CO2 as a constituent gas of the atmosphere make it the present primary controller of the level of global temperature. Multivariate analyses (sometimes called Monte Carlo analyses) have eliminated the likelihood of all sources for excess CO2 except human activity. Anthropocentric CO2 production is at the heart of global warming, and only humans can change it. However, the near-catastrophic truth is... the synergy of the impacts described above may make it too late to do that without draconian measures, measures no government is likely to take. People who insist "market forces" should be allowed to function in this arena need to rethink. "Market forces" won't address the issue until it's far too late. Major manufacturers, energy companies and fossil fuel production companies are focused on quarterly profits. Without government leadership, even government forcing, the market will procrastinate until there is no tomorrow.
Photos: Wikipedia Commons