We have less time than expected to achieve the most ambitious objective of the Paris Agreement, namely limiting the rise in global average temperature to a maximum of 1.5 degrees centigrade by the end of the century, relative to pre-industrial levels. Taking into account the current pace of emissions of greenhouse gases dispersed into the atmosphere every year as a result of human activities, we have only six years left to reverse course.

This is explained by a study published in the scientific journal Nature Climate Change, which has calculated the current trajectory of global average temperature, taking into account the fact that every year the world continues to release into the atmosphere approximately 40 billion tonnes of CO2. And considering that the planet has already warmed by 1.2 degrees compared to before humans began burning coal, oil and gas.

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⌛️If carbon emissions continue at their current pace, there might be just 6 years left to prevent #GlobalWarming from surpassing 1.5°C, according to new research by IIASA & @imperialcollege, published in @NatureClimate. #ClimateAction #ClimateCrisis #parisagreement

♥ 39💬 1 31 ott 2023 · Apri su X →

Reaching 1.5 degrees would require an immediate and drastic reduction in CO2 emissions

The researchers, led by Robin Lamboll of Imperial College London, have therefore recalculated the so-called "carbon budget" — that is, the maximum quantity of carbon dioxide we can afford to release into the atmosphere without breaching the 1.5-degree ceiling. In practice, the reduction in emissions would need to be immediate and drastic. A scenario that is in no way visible at a global level, also considering the multiple speeds of the ecological transition, which vary enormously from country to country.

Joeri Rogelj, one of the scientists who took part in the calculation, is in this respect decidedly radical in his analysis: "It is clear that the chances of limiting global warming to 1.5 degrees are exhausted. Already this year it is highly likely that this level will be touched." Even so, for the planet to be considered as having "reached the threshold," it must not be a peak but a stable value. The trend is, however, objectively alarming.

Why this does not mean we should give up on the climate

The latest estimates from the European consortium Copernicus already indicate that 1.5 degrees could be stably reached from 2034 onwards, if not sooner according to other studies — well ahead of the mid-century date previously hypothesised. This will cause immediate consequences in terms of impacts on our lives, through the multiplication of extreme weather events, increases in heatwaves and droughts, the accelerated melting of Alpine glaciers and the melting of the polar ice caps, with everything that this will entail in terms of sea level rise as well.

Further cause for concern are the other greenhouse gases, starting with methane, which could further accelerate the global warming process: "It is like playing Russian roulette," Rogelj continues. He nonetheless underlines that such findings do not in any way mean that one can or should give up. "Even if we fail to limit the rise in global average temperature to 1.5 degrees, cutting emissions will give us more chance of staying at 1.6 or 1.7 degrees. Which would still be an excellent result given the direction we are currently heading in."

The current trajectory would in fact lead to reaching 2.4 degrees centigrade by 2100. And that is on the condition that governments around the world keep the (insufficient) promises made so far. Which is by no means certain, if only because governments change their political colour and very often their stance on the climate issue as well.