Philos Trans A Math Phys Eng Sci
January 2022
Removing methane from the air is possible, but do the costs outweigh the benefits? This note explores the question of whether removing methane from the atmosphere is justifiable. Destruction of methane by oxidation to CO eliminates 97% of the warming impact on a 100-yr time scale. Methane can be oxidized by a variety of methods including thermal or ultraviolet photocatalysis and various processes of physical, chemical or biological oxidizers.
View Article and Find Full Text PDFLower heating of our planet by the young Sun was compensated by higher warming from factors such as greater greenhouse gas concentrations or reduced albedo. Earth's climate history has therefore been one of increasing solar forcing through time roughly cancelled by decreasing forcing due to geological and biological processes. The current generation of coupled carbon-cycle/climate models suggests that decreasing geological forcing-due to falling rates of outgassing, continent growth, and plate spreading-can account for much of Earth's climate history.
View Article and Find Full Text PDFThis paper presents statistical estimates for the location and duration of habitable zones (HZs) around stars of different mass. The approach is based upon the assumption that Earth's location, and the Sun's mass, should not be highly atypical of inhabited planets. The results support climate-model-based estimates for the location of the Sun's HZ except models giving a present-day outer-edge beyond 1.
View Article and Find Full Text PDFAnalyses of bulk petrographic data indicate that during the Late Paleozoic wildfires were more prevalent than at present. We propose that the development of fire systems through this interval was controlled predominantly by the elevated atmospheric oxygen concentration (p(O2)) that mass balance models predict prevailed. At higher levels of p(O2), increased fire activity would have rendered vegetation with high-moisture contents more susceptible to ignition and would have facilitated continued combustion.
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