Fig. 1. Annual increase of climate forcing by greenhouse gases. "One implication of the increased growth rate of GHG forcing in the last 15 years is that the goal to keep global warming under 2°C is now implausible. IPCC defined a GHG scenario (RCP2.6) intended to provide a 66% chance of keeping global warming below 2°C. Actual growth of GHG forcing has diverged dramatically from that scenario (Fig. 1), with reality being close to the extreme RCP8.5 scenario. The gap between reality and RCP2.6 could be closed by capturing and storing CO2 (carbon capture and sequestration, CCS), but the annual cost for the gap at January 2023 (the time of the last 60-month mean) would be $2.4-5 trillion[4] with current technology, and the gap and annual cost are increasing.
https://jimehansen.substack.com/p/warning-this-colorful-chart-is-censored
RCP2.6, in fact, was never plausible, as it relied on assumption of large-scale biomass-burning at powerplants with carbon capture and permanent storage of the captured CO2, a scheme that would ravage nature and threaten food security.[5] We scientists must share the blame, if we allow policymakers to believe that such scenarios provide a realistic projection of climate change.
Missed opportunities to phase down the growth of GHGs are worth understanding because that knowledge can aid development of future policies. Useful information on climate change and energy policy was already available in 1988, when IPCC was formed. Global reserves of conventional fossil fuels (coal, oil, gas) clearly were enough to cause climate change, albeit of uncertain magnitude. The science community had been asked, at least implicitly, if it made sense to develop unconventional fossil fuels to succeed coal, oil, and gas as a major source of world energy. The famous Charney report[6] on climate change was requested by the Science Adviser of U.S. President Jimmy Carter because of concern about potential climate effects of Carter’s plans for coal gasification and the fossil fuel industry’s budding efforts in hydrofracturing of rock formations (fracking) to extract “tight” oil and gas. In subsequent decades, scientific concern about the threat of human-caused climate change grew continually."
No comments:
Post a Comment