It is now clear that the incremental-adjustment 2°C strategy has run out of time, if for no other reason than the “budget” for burning more fossil fuels is now zero, yet the global economy is still deeply committed to their continuing widespread use.
We all wish the incremental-adjustment 2°C strategy had worked, but it hasn’t. It has now expired as a practical plan.
We now have a choice to make: we can accept much higher levels of warming of 3–5°C that will catastrophically affect the world’s natural and human systems in a manner more forthright scientists say are incompatible with the maintenance of human civilisation; or we can conceive of a safe-climate emergency-action approach which would aim to reduce global warming back to the range of conditions experienced during the last 10,000 years, the period of human civilisation and fixed settlement.
This would involve fast and large emissions reduction through radical energy demand reductions, whilst a vast scaling-up of clean energy production was organised, together with the remaking of many of our essential systems such as transport and food production, with the target being zero net emissions. In addition, there would need to be a major commitment to atmospheric carbon dioxide drawdown measures. This would need to be done at a speed and scale more akin to the “war economy”, where social and economic priority is given to what is perceived to be an overwhelming existential threat.