Solar control of global mean temperature outweighed since 1940s by anthropogenic warming (by airborne soot, not CO2): literature synthesis

Roger Higgs 

Primarily solar control of global warming and cooling for the last 9,000 years is proven by the striking likeness between published graphs of (1) average near-surface air temperature (from proxies and, since 1880, NASA-GISS thermometer data) and (2) solar-magnetic output. Graph-to-graph visual cross-matching of spikes and multi-century trends reveals a ~150-year temperature lag, attributable to ocean thermal inertia. The graphs clearly decouple in the 20th Century, 1940 to 2024 being disproportionately warm for the corresponding (time-lagged) solar output. Implicating humankind, this excess warmth coincides with the large growth, from World War Two onwards, in worldwide combustion of oil (aircraft, ships, vehicles) and coal (electricity production; steel- and cement-making). Further incriminating humans but exonerating carbon dioxide (CO2), NASA's temperature graphs show that warming since 1985 is spatially inhomogeneous: much faster over land than ocean; faster in the Northern Hemisphere (land-ocean average) than the Southern; and nil in Antarctica (i.e. 'global warming' is not global). This spatial heterogeneity, at odds with CO2's globally homogenous atmospheric concentration, instead implicates airborne soot (absorbs solar radiation, thereby warming adjacent air), emitted mostly in the northern-hemisphere and on-land, mainly by burning coal, diesel-oil and wood (home-cooking by billions of people lacking electricity). Therefore, CO2's greenhouse effect is presumably offset by feedbacks underestimated or omitted in climate models (e.g. cloud effects fraught with uncertainty). Simply freezing world coal combustion at today's levels would halt airborne-soot growth, thus ending anthropogenic warming in ~10 years. Nevertheless, a sea-level rise of ~3 metres by 2100 appears inevitable (companion article by the author, in review). An even higher rise might be avoided by an urgent global shift from coal to natural gas (almost soot-free) for electricity generation. World gas reserves are sufficient for decades, giving time for development of 'clean' (no soot or radioactive-waste), potentially limitless, nuclear-fusion energy.