On climate change, mind the science-policy gap

In 2023, scientists began debating the need to quantify the extent of global warming. Natural fluctuations, such as El Niño, made it difficult to ascertain if the faster rise in temperatures was due to climate change. Now, an analysis by Stefan Rahmstorf of the University of Potsdam, Germany, and US statistician Grant Foster has confirmed the links between the two. The researchers isolated the influence of phenomena such as El Niño, volcanic eruptions and solar irradiance to affirm that the pace of global warming has doubled since 2014, compared to the decade before it. Their study, published in Geophysical Research Letters a few days ago, reckons that the Paris Pact’s target of keeping temperature rise to below 1.5 degrees Celsius below pre-industrial levels could be out of reach by 2030. The study comes in the wake of a Nature paper that concludes that sea-level rise — caused by global heating — could be far higher than previously understood, including in IPCC reports. The two studies confirm the fears of scientists — the climate system is already in uncharted territory. As another analysis, published on Tuesday in the journal Environmental Research: Health, points out, a third of the world’s population now lives in areas — including large parts of India — where heat severely limits human activity.

It took careful diplomacy to include the 1.5-degree target in the Paris Pact. Since then, diplomacy has not kept pace with science. Take the net-zero target. Two different methodologies are used to calculate this goal — one deployed by IPCC scientists and a much looser method adopted by national policymakers. The latter, criticised for not reckoning with the fact that multiple entities can claim the same emission cuts, has found its way into climate negotiations. Scientists who framed the net-zero concept warn that reliance on this method will artificially inflate progress.

Every fraction of a degree of warming will make adaptation more expensive. As the Environmental Research: Health study warns, extreme heat will affect not only the elderly but also the young and healthy. Public health experts, agriculture scientists and energy specialists have blueprints to increase resilience. It’s up to policymakers to make optimum use of their inputs.