Few people appreciate what it’d mean to take our climate goals seriously.
To hit the Paris climate goals without geoengineering, the world has to do three broad (and incredibly ambitious) things:
1) Global CO2 emissions from energy and industry have to fall in half each decade. That is, in the 2020s, the world cuts emissions in half. Then we do it again in the 2030s. Then we do it again in the 2040s.
2) Net emissions from land use — i.e., from agriculture and deforestation — have to fall steadily to zero by 2050. This would need to happen even as the world population grows and we’re feeding ever more people.
3) Technologies to suck carbon dioxide out of the atmosphere have to start scaling up massively, until we’re artificially pulling 5 gigatons of CO2 per year out of the atmosphere by 2050 — nearly double what all the world’s trees and soils already do.
2020-2030: … carbon pricing would expand to cover most aspects of the global economy, averaging around $50 per ton and rising. Coal power is phased out in rich countries by the end of the decade and is declining sharply elsewhere. … Wealthy countries no longer sell new combustion engine cars by 2030, and transportation gets widely electrified, with many short-haul flights replaced by rail. … In addition, spending on clean energy research increases by “an order of magnitude” this decade … By 2030, we’d need to be removing 100 to 500 megatons of CO2 each year and have a sense of how to scale up.
None of this is easy. It might well prove impossible. But this is roughly what staying well below 2°C entails