We keep hearing scare stories about cow farts and peat bogs emitting methane that will destroy the planet.
Methane is responsible for nearly as much global warming as all other non-CO2 greenhouse gases put together. Methane is 23 times more powerful a greenhouse gas than CO2. While atmospheric concentrations of CO2 have risen by about 31% since pre-industrial times, methane concentrations have more than doubled.
I tried an experiment on RRTM – the radiative transfer model used in NCAR’s climate and weather models. A 10X increase in methane in the tropics increases downwelling LW radiation by less than one fourth of one percent. A 100X increase in cow farts increases downwelling LW radiation by less than one percent. A 1000X increase in methane increases downwelling LW radiation by a little over one percent.
Now consider water vapor – normal changes in humidity from day to day can easily alter the amount of downwelling longwave radiation by 10%.
Runaway methane is yet another climate superstition being preached by the world’s #1 rated scientist. There just isn’t a lot of methane in the atmosphere. It is a reactive gas with a short residency time.
This is what I have always thought…. if nearby tipping points were real, one humid day would have set it off.
Just FYI, cows mainly belch methane rather than farting it. I did think I saw a small uptick at the end of the chart, but it was a speck on my screen.
An alarming rise in methane.
Don’t the IPCC ever learn from their mistakes.
Re: IPCC new guidelines
“But notice what has not found a place on the IPCC’s new unacceptable list – publications produced by advocacy organizations and pressure groups. As in Greenpeace. As in the World Wildlife Fund……………….
Yet despite the embarrassment this has caused the IPCC (the erroneous Himalayan glacier melt date came from a WWF publication), the IPCC is proposing an update to its policies that utterly ignores this very real, known, and substantive issue. ”
http://nofrakkingconsensus.com/2011/04/21/clueless-new-ipcc-policies-ignore-advocacy-literature/
So methane is not the so-called wild card in the AGW nightmare scenarios that we have been scared about.
If *ANY* mechanism that functions in the atmosphere were capable of positive feedback leading to a “runaway” reaction senario, quantum fluctuations would guarantee that it would have started within the time allotted for one molecular vibration / intermolecular collision / radiative enegy absorption event. Such events are extremely difficult to trigger in nature, as the Manhattan Project demonstrated in the 1940’s.
That would leave approximately 4,500,000,000 years for the consequences of any such mechanism to manifest themselves globally. Any global warming ‘tipping point’ would have been achieved long before life even evolved on this planet.
The changes in the earth’s climate that some interpret as long-term changes must therefore not be catastrophic or even secular, but quasi-periodic with a recurrence
period that simply exceeds the temporal range of the available data.