RC Parida and PK Ghosh

The UN Environment Programme, in its report titled “The Closing Window” confirmed in 2022 that there is almost no credible pathway to limit global warming within 1.5°C above the pre-industrial temperature based on the 2030 commitment. Therefore, it has been suggested to aim at keeping it at 2°C, which only can be achieved if all the countries meet their pledges to achieve net-zero emissions.

However, from the ongoing trend, it can hardly be guaranteed. Moreover, even if we succeed in stopping carbon dioxide emissions today, the long-term impact of the gas already in the air will continue for decades. On the other hand, modelling suggests that any warming above 1.5°C may increase the risk of self-reinforcing tipping points in the global climate system, which are the temperature thresholds at which significant greenhouse gases can be released suddenly, greatly amplifying global warming. An example is the release of frozen carbon dioxide and methane stores from the thawing Arctic permafrost. Therefore, an increase to 2°C may invite such possibilities. For such reasons, it is now necessary to focus not only on arresting global warming but also on reversing it…read more on NOPR