Over 1.5 °C: the Paris threshold will be exceeded



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Over 1.5 °C: the Paris threshold will be exceeded

Within 2030 global warming will definitely exceed the 1.5 °C, what was established by the 2015 Paris climate agreement. The forecast bears the signature of the Australian Climate Council and is splitting into two observers, experts and climate scientists.

Carl-Friedrich Schleussner of Humbolt University in Berlin and Bill Hare of Climate Analytics share a dossie in which it seems it is too late to avoid exceeding 1.5 ° C of global warming. One of the most relevant points is to correctly estimate the amount of carbon dioxide and other climate-altering gases that each country can still emit into the atmosphere before the threshold of 1.5 ° C is collectively reached.

There is also little scientific agreement on how to calculate this parameter. So much so that the scientist cites some recent studies in which estimates are provided, but specifying that the margin of error can be as much as 50%.

The future increase in global temperatures that derives from the current situation but which will become visible and evident only in the coming years with the triggering of positive feedback mechanisms. According to the report, the accumulated emissions up to 2020 could alone push the Paris lower threshold.

Over 1.5 °C: the Paris threshold will be exceeded

Equilibrium climate sensitivity (ECS) indicates the increase in global average temperatures in the atmosphere over the long term as a function of a doubling of the value of the CO2 concentration in the air.

The new estimates of the WCRP keep the upper margin of the IPCC unchanged, but revise the lower one upwards, causing it to rise to 2.3 ° C. The other two factors taken into consideration by the Climate Council are the comparison with the impacts of climate change in the past and the analysis of the remaining global carbon budget.

The contribution of paleoclimatology can actually be important to build more accurate predictive models of the climate and it is no coincidence that there are many studies that start from the study of the ancient climate to gain information about our future.

With CO2 concentration values ​​in the atmosphere like the current ones, in some past eras global temperatures, sea levels and other parameters were much worse than today The conclusion reached by the report is that several lines of evidence contribute to the argument that we cannot limit the increase in the global average surface temperature to 1.5 ° C above the pre-industrial level.