Illustration provided on January 20, 2016 by NASA showing global warming -

HANDOUT AFP

Almost all of the global warming that has occurred since the start of the industrial age has been caused by human activities.

A study published on Monday in the journal

Nature climate change

estimates that natural processes are "negligible" in this area.

Since the middle of the 19th century, the planet has gained more than 1 ° C.

Researchers wanted to determine how much of this warming was caused by greenhouse gas emissions from human activities and how much was linked to "natural forcings", natural factors such as large volcanic eruptions or fluctuations in solar radiation.

Unmistakable results

Scientists therefore reviewed 13 different climate models to simulate temperature changes under three scenarios.

In the first, aerosols are the only contributors to warming, in the second, only natural forcings are considered, and in the third, greenhouse gas emissions are taken into account.

Conclusion: human activity has contributed to the warming by 0.9 to 1.3 ° C, an estimate in line with the current warming.

“Our results clearly show that global warming is caused primarily by humans,” commented Nathan Gillet, co-author of the study.

Ambitiously reducing emissions

The 2015 Paris agreement aims to keep global warming below + 2 ° C, if possible + 1.5 ° C.

But to achieve the latter goal, emissions would have to be reduced by 7.6% per year between 2020 and 2030, according to the UN.

A figure similar to the drop measured in 2020 due to the coronavirus pandemic.

Given the magnitude of the estimate of this latest study, human warming "could already be close to the limit of 1.5 ° C".

“If warming […] is at the bottom of the range, the 1.5 ° C target is still achievable with ambitious and rapid reductions in emissions,” notes Nathan Gillet.

But at the top of the estimate, "the 1.5 ° C target could be practically impossible."

Planet

CO2 emissions from air transport fell by more than 50% in 2020 in Europe

Planet

Dolphins suffer from deadly skin disease due to global warming

  • Environment

  • Planet

  • Climate change

  • Global warming

  • Greenhouse gas