Timothy Birdnow

Geothermal activity may be responsible for part of the warming we have witnessed on Earth over the last few decades. According to this paper:

"One important geophysical variable that is conspicuously absent from both the IPCC and NIPCC assessments is the flux of geothermal energy. The principal reason for geothermal’s exclusion is that, despite large uncertainties in the geothermal contribution to earth’s heat budget [3], the average global geothermal flux is estimated to be just 91.6 milliwatts per square meter (mWm-2), an amount considered by many to be too small to impact global temperatures in an appreciable way [4]. By contrast, the direct anthropogenic thermal load to the atmosphere is 28 mWm-2 [5] and, as detailed in AR5, the total industrial-era RF from resident anthropogenic gases is estimated to be 2.29 Wm-2.

However, the majority of earth’s geothermal heat is released along the mid-ocean spreading zones [4,6], a 67,000 km tectonic complex for which we have very little data (Figure 1). The problem in accurately assessing heat flow from these high geothermal flux areas (HGFA) is that they are poorly sampled. Located in the middle of ocean basins at great depths, they are far removed from the predominantly land-based seismic network. According to Langmuir and Forsythe [7], we are still in the "very early stages of understanding” these extensive, complex tectonic systems."

end excderpt.

While correlation is not causality, one wonders if Milankovich Cycles are better understood if one factors this in; changes in the Earth's movement may cause increased (or decreased) undersea geothermal activity.

It's an interesting point.

Posted by: Timothy Birdnow at 09:44 AM | Comments (7) | Add Comment
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