ie, we only need to reduce our emissions by 48% to achieve net zero and we’ll need to increase emissions to sustain current concentrations thereafter.
@aaronshem 1/9. Aaron wrote, "ie, we only need to reduce our emissions by 48% to achieve net zero" If "net zero" were rationally defined, that'd be correct. But the "net zero" definition excludes natural CO2 removal. It's defined as "zero emissions." https://www.ipcc.ch/sr15/chapt...
@aaronshem 2/9. So a 48% emission reduction would halt the CO2 rise, but it would not "achieve net zero." "Achieving net zero" would cause the CO2 level in the atmosphere to fall, initially at the then-current rate of natural CO2 removals (which is currently 2.7±0.9 ppmv/year).
@aaronshem 3/9. Another way to cause the CO2 level to stop rising is to simply let it rise! No emission reductions are needed. Are you surprised?
@aaronshem 4/9. CO2's "adjustment time" of ≈50 years means that for each 50 ppmv increase in CO2 level, natural CO2 removals accelerate by ≈1 ppmv/year. So after a rise of only another ≈125 ppmv, natural CO2 removals will approximately equal today's entire human CO2 emission rate. That
@aaronshem 5/9. So if the current rate of CO2 emissions were to continue indefinitely the CO2 level could only rise about 125 ppmv (≈30% of a doubling). That would yield only 37% of the "forcing" (warming effect) to be expected from a full doubling of CO2: https://www.google.com/search?...
@aaronshem 6/9. For comparison, since the start of the industrial revolution in the 1700s (during the late Little Ice Age) we've already seen 60% of the forcing from a doubling of CO2. As Arrhenius predicted, the effects have been overwhelmingly salubrious: longer growing seasons, much
@aaronshem 7/9. There's no good reason to fear that another 37% could be harmful, instead of beneficial like the last 60%, let alone a "crisis" or "emergency." The evidence is compelling that manmade climate change is modest & benign, and CO2 emissions are beneficial https://sealevel.info/learnmor...
@aaronshem 8/9. BTW, the short (50 year) measurement-derived adjustment time for CO2 has been independently calculated from measurements by many researchers (including me), and was even mentioned in the IPCC's Second Assessment Report. https://x.com/ncdave4life/stat... Unfortunately, recent IPCC
@aaronshem 9/9. The bottom line is that no emission cuts at all are required to limit the rise in CO2 concentration to a modest and unthreatening level, and the entire "net zero" campaign is based on pseudoscientific homeopathic climatology. https://x.com/ncdave4life/stat...