ATMOSPHERIC METHANE AND CLIMATE CHANGE
Mike Priaro, P.Eng.
First uploaded January 3, 2018
There are a number of sources of methane, the second-most important greenhouse gas, in the atmosphere. These sources include: biomass burning (forest fires), biogenic (agricultural, livestock, ruminants, insects, microscopic organisms), natural (forests, wetlands, and oceans), fossil fuels, and geological (permafrost, hydrates, and Earth's crust and mantle).
In approximate order, the largest sources of methane in the atmosphere are: natural wetlands, fossil fuels, rice agriculture, livestock and ruminants, biomass burning, and landfills though there are differences in those rankings among researchers.
On the whole, atmospheric methane is increasing. The concentration of methane in Earth's atmosphere is reported to have increased by about 150% since 1750, and it now accounts for 20% of the total radiative forcing from all of the long-lived and globally mixed greenhouse gases (Source: Climate Change 2001. United Nations Environment Programme). Of course that statement is based on the controversial assumption that greenhouse gases cause climate change - and not the other way around.
Source: European Environmental Agency
Note also that in the chart above, the actual data is in blue. The red curve is an extrapolation based on unscientific mathematical curve fitting whose purpose can only be fear-mongering and attention-getting sensationalism.
A recent paper in Nature concludes that recent reductions in forest fires accounts for the smaller than expected recent increases in atmospheric methane.
However, the contribution of the many different sources of atmospheric methane is exceedingly difficult and complex to determine with any accuracy.
On top of that, the effect of methane on future climate is not possible to determine because in the paper’s authors' own words “...there is effectively no confidence in projections of future atmospheric methane concentrations.”
Finally, the inherent inadequacy and incompleteness of all climate change models adds another level of compounding error in creating climate change forecasts.
How can there be any scientific confidence in climate change models under such circumstances?
This is even more true because many of the same inadequacies of climate change models and in regard to the sources and effects of greenhouse gases on Earth’s climate also apply to carbon dioxide, the most important greenhouse gas.
Mike Priaro, P.Eng.
Calgary
403-281-2156
