5. How we can safely turn down our abnormal greenhouse effect, warming and climate extremes (Walter Jehne).
Three key variables govern the greenhouse effect; the amount of heat being re-radiated by the Earth and the numbers of water vapour and CO2 molecules in the air to absorb it, before their saturation.
As indicated above we can simply practically and rapidly turn down the amount of heat being re-radiated to safely minimize its abnormal warming effects. As outlined in points #6 and #7 we can also beneficially remove the additional 50,000 ppm of water vapour from the air as a result of the persistent humid hazes. Seasonally and regionally this now constitutes up to 80% of our abnormal greenhouse effect.
Provided we returned both of these dominant greenhouse determinants to their natural buffered states the slightly enhanced greenhouse warming (0.2-0.3oC) from the fact that CO2 levels have risen abnormally to some 410 ppm over 250 years is not dangerous, acute and can be readily offset via the dominant re-radiation and water vapour variables.
In any case, ocean buffer and lag effects dictate that it may take centuries of even negative carbon emissions due to major drawdown levels to return CO2 levels and its minor greenhouse effect back to natural pre-industrial levels.
As discussed in Regenerate Earth and #10 below, urgent action will be needed to draw down up to 20 billion tonnes of carbon per annum from the air as negative emissions so as to regenerate the Earth’s soil carbon sponge and restore these natural hydrological cooling and safe climate buffering processes, not simply to reduce emissions or return CO2 to 300 ppm or some nominal level.
Walter explains the role of water in the greenhouse effect from about 1.10.40 in this video.