After Gutenberg

We are closer to losing the Arctic ice cover in summer than previously thought. This scenario is an example of a tipping point and how likely even “moderate additional” greenhouse emissions are likely to push Earth past “critical tipping points” with “dangerous consequences for the planet.”

NASA’s QuikScat satellite provides images that indicate Arctic sea ice not only shrinking in coverage area; it also is thinning.

And, according to a preliminary analysis for NOAA’s annual greenhouse gas index, which tracks data from 60 sites around the world, “emissions of two of the most important climate change gases increased last year.” Green Car Congress reports that “NOAA researchers measured an additional 16.2 billion tons of carbon dioxide (CO2)—a byproduct of fossil fuel burning—and 12.2 million tons of methane in the atmosphere at the end of December 2008.”

The GCC article notes that the level of CO2 and methane in the atmosphere continued to rise in 2008 despite an economic slump. This blog recently made note of a possible explanation made by Shakeb Afsah of Climate Data Due Diligence, why, despite the global economic downturn, with its decrease in a wide range of activities that depend on fossil fuel use, these GHG would increase. Basically, the reason that carbon emissions continued to rise is that dirty electric power production is still cheaper than cleaner electric power production.

Methane on the other hand is increasing because the permafrost already is melting. Joseph Romm explains:

As a major 2008 study found, Permafrost loss linked to Arctic sea ice loss:

We find that simulated western Arctic land warming trends during rapid sea ice loss are 3.5 times greater than secular 21st century climate-change trends. The accelerated warming signal penetrates up to 1500 km inland….

In other words, the recent trend in sea ice loss is poised to triple Arctic warming, causing large emissions in carbon dioxide and methane from the tundra this century. What is especially worrisome is that 2007 and 2008 provide strong evidence on behalf of this theory:

• NOAA just reported that “methane levels rose in 2008 for the second consecutive year after a 10-year lull.”
• The tundra can emit vast amounts of methane when it defrosts (see Part 1).
• Scientific analysis suggests the rise in 2007 methane levels came from Arctic wetlands (see here).
• And 2007 saw record Arctic ice loss [see "Ice Ice Maybe (not)"] — as did 2008 (see “here)

Related Climate Progress Posts:

• A methane feedback from the past strikes again
• Methane Hydrates: What’s the worst — and best — that could happen?