The climate system is more sensitive than expected to anthropogenic greenhouse gas emissions, with the result that global warming is accelerating faster than estimated. We could therefore exceed the 1.5 degree threshold within ten years from now, and reach an additional 2 degrees around 2050. This is according to a study published in Oxford Open Climate Change by James Hansen.
The starting point is a reassessment of the sensitivity of the Earth’s climate to variations of carbon dioxide in the atmosphere. With a doubling of CO2 compared to the pre-industrial era. Using up-to-date data, it has been established that the global temperature increase for the same amount of additional CO2 can reach +4.8°.
Until now, the lower estimates were because air pollution has shielded some of the incoming solar radiation to Earth. But with a reduction in emissions and a gain in health, comes an increase in temperature.
The study attempts to quantify what the effect of the gradual disappearance of aerosols might be on global temperatures. Thus, if global warming has been running at the rate of +0.18°C per decade between 1970 and 2010, after that date it will jump to +0.27°C and at these rates, we will already exceed 1.5 degrees before 2030