"Level of Heat-Trapping CO2 Reaches New High, Growth Rate Speeds Up, Methane Levels Are Rising Again"
The World Meteorological Organization reported today that:
The amount of greenhouse gases in the atmosphere reached a new high in 2010 since pre-industrial time and the rate of increase has accelerated, according to the World Meteorological Organization’s Greenhouse Gas Bulletin….Between 1990 and 2010, according to the report, there was a 29% increase in radiative forcing — the warming effect on our climate system — from greenhouse gases. Carbon dioxide accounted for 80% of this increase.
This report on record CO2 levels (analogous to the level of water in a bathtub) comes on the heels of a record surge in CO2 emissions (analogous to the water coming out of the faucet) — see Biggest Jump Ever in Global Warming Pollution in 2010.
The speed up in the growth rate of CO2 levels is obviously worrisome (although it was predicted by climate science):
Between 2009 and 2010, its atmospheric abundance increased by 2.3 parts per million – higher than the average for both the 1990s (1.5 parts per million) and the past decade (2.0 parts per million).
For about 10,000 years before the start of the industrial era in the mid-18th century, atmospheric carbon dioxide remained almost constant at around 280 parts per million.
We are disrupting at an accelerating pace what had been a very stable climate system for the entirety of human civilization. Not very bright.
The other worrisome aspect of the surge in GHG is return of growth in methane, a highly potent GHG. The WMO reports:
Methane (CH4) contributes about 18% to the overall global increase in radiative forcing since 1750 and is the second most important greenhouse gas after carbon dioxide.
Before the start of the industrial era, atmospheric methane was about 700 parts per billion (number of molecules of the gas per billion molecules of dry air) Since 1750, it has increased 158%, mostly because of activities such as cattle-rearing, rice planting, fossil fuel exploitation and landfills. Human activities now account for 60% of methane emissions, with the remaining 40% being from natural sources such as wetlands.
After a period of temporary relative stabilization from 1999 to 2006, atmospheric methane has again risen. Scientists are conducting research into the reasons for this, including the potential role of the thawing of the methane-rich Northern permafrost and increased emissions from tropical wetlands.
I don’t think the role of emissions from fracking and unconventional gas can be completely discounted (see “Leakage of methane from fracking boosts shale gas global warming impact”).
The Bulletin states:
The reasons for the renewed increase in CH4 are not fully understood and several factors, mostly biogenic, were reported to contribute to this increase.
Here is a post on the destruction of the tropical wetlands. But the biggest worry is the
permafrost permamelt, which contains a staggering “1.5 trillion tons of frozen carbon, about twice as much carbon as contained in the atmosphere, much of which would be released as methane. Methane is 25 times as potent a heat-trapping gas as CO2 over a 100 year time horizon, but 100 times as potent over 20 years!
A study from earlier this year by National Snow and Ice Data Center projected that thawing permafrost feedback will turn Arctic from carbon sink to source in the 2020s, releasing 100 billion tons of carbon by 2100. We just learned of the Peatlands Amplifying Feedback: Drying Wetlands and Intensifying Wildfires Boost Carbon Release Ninefold (much of which would be methane).
We need to start aggressive mitigation now as every major independent study concludes.
- Humans boosting CO2 14,000 times faster than nature, overwhelming slow negative feedbacks: Lead author Zeebe, “Right now we have put the system entirely out of equilibrium.“ He notes that, “the average change in the amount of atmospheric carbon dioxide over the last 600,000 years has been just 22 parts per million by volume.” Humans have run up CO2 levels 100 ppm over the last two centuries!
- Science: Vast East Siberian Arctic Shelf methane stores destabilizing and venting: NSF issues world a wake-up call: “Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming.” Methane and carbon release from the Arctic is the most dangerous amplifying feedback in the entire carbon cycle. This research finds a key “lid” on “the large sub-sea permafrost carbon reservoir” near Eastern Siberia “is clearly perforated, and sedimentary CH4 [methane] is escaping to the atmosphere.”