We have already raised CO2 in the atmosphere from about 280ppm to 400ppm. If it continues to climb to 500ppm we could reach a point of no return, where nothing we can do will prevent further warming due to the loss of polar ice and permafrost melt.
• Betting on a brighter future
This year looks certain to be the hottest on record, at about 1.2degC above pre-industrial levels.
According to Climate Action Tracker analysis, the world is on course for about 3.6degC warming by the end of the century. If everyone met their Paris commitments that could be cut to about 2.8degC, still too high. According to its analysis, New Zealand sits among a large number of countries with inadequate Paris pledges, consistent with warming of up to 4degC.
What might bridge the gap between energy demand and the requirement to cut emissions, is the commercialisation of fusion energy, which involves fusing heavy hydrogen atoms to form helium and harnessing the energy released in the process. It is clean, green and involves no radioactive waste. The first fusion plant could be generating by 2050.
On that basis, we need to stall for time, and climate engineering might be the answer.
