From intentions to acts: the call of IPCC’s climatologists

Differentiated risks for water resources

The half degree between 1.5°C and 2°C may seem negligible. However, it is decisive. Keeping the temperature increase to 1.5°C would permit reducing the number of people exposed to climatic risks from now to 2050 by several hundred million and reduce by half the proportion of the world’s population exposed to hydric stress. In a scenario at 1.5°C, 350 million human beings will be faced with floods, 410 million in one at 2°C. In the latter case, the sea level will rise by 0.1 m, leading to the disappearance of the most vulnerable land, meaning river deltas and islands, coastal erosion and increased salinization of soil. The lack of water, the development of infectious diseases, and a fall in crop yields leading to a reduction of food security are some of the risks caused by these impacts of climatic deregulation.

Reaching carbon neutrality by 2050

IPCC’s experts did not only analyse the impacts. They defined for the first time the conditions required to limit temperature increases and called on every sector to make “radical reductions of CO₂ emissions”.

The aim: to reduce emissions by 45% by 2030 – although France’s CO₂ emissions continued to increase in 2017 – and to target carbon neutrality by 2050 at the latest if the minimal scenario of +1.5 C is to be achieved. Major and rapid efforts are needed in cities, industry and transport; and words must be transformed into acts, according to them. We bear great responsibility to future generations and it is shared between citizens, and political, industrial and financial decision-makers.

* ceiling fixed by the Paris 21 Agreement by 2100.