INVESTIGATION – In France 2050. RCP8.5, the black climate scenario, journalist Marc Lomazzi asked experts what would happen to our country if nothing was done to limit global warming. The painting is apocalyptic.
Of all the scenarios established by the climatologists of the Intergovernmental Panel on Climate Change (IPCC), RCP8.5 is the worst. RCP (Representative Concentration Pathways) designates the possible trajectories of greenhouse gas concentrations. The 8.5 means an additional 8.5 watts per square meter. If RCP8.5 came true, the world « would be 5 warmer or 6 °C in 2100 »says Marc Lomazzi, who interviewed around fifty scientists to write France 2050. RCP8.5, the black climate scenario (1).
The former journalist Parisian describes the consequences of « climate chaos » predicted by IPCC experts on our daily lives. He assures that it is not for « scare » that he chose the worst-case scenario, but quite simply because « this worst is already certain on this horizon » and « without awareness of the reality of the situation, the public policies likely to correct the current trajectory of warming so that things improve in the second half of the XXIe century will not be carried out ».
Read alsoErosion and rising sea levels: on the Normandy coast, resist or retreat
Marc Lomazzi’s company is therefore intended to be educational. Like the approach of the IPCC, which deliberately publishes certain scenarios whose probabilities of occurrence are almost nil, whether they are optimistic or pessimistic. In its August 2021 report, for example, the IPCC shows two curves of a sudden slowdown in global warming which could only happen if humanity completely stopped using fossil fuels. Knowing that more than 82% of the energy consumed today on the entire planet comes from oil, coal and gas, one can imagine what renunciations our civilization would have to consent to if it deprived itself of these resources, and the chaos, economic and social this time, which would result!
“Get everyone on board”
Conversely, the steeply rising curve by 2100 – the famous RCP8.5 – would suppose that the use of fossil fuels would be multiplied by three, while the state of world reserves and the technical possibilities of such intensive exploitation make this highly improbable hypothesis.
Marc Lomazzi is not a follower of collapse theories. He even dedicated his previous book, Ultra ecologicus (2), to the prophets of radical ecology. He wants to challenge those he considers to be the actors of climate change, citizens, business leaders and political decision-makers, because he is convinced that we must « get everyone on board » so that humanity thwarts the worst prognoses.
Heat spikes
Between 1976 and 2009, the summer mercury climbed well above 30°C only in the South and along the Rhone axis. The heat wave of 2003 is an exception, but it foreshadows the summer heat to come.
In the middle of the century, France will not escape the multiplication of heat waves and tropical nights. In the worst-case scenario, three-quarters of France will suffer during the summer, including north of the Loire, extreme heat with peaks of 50°C.
Forest fires
The Weather Forest Index (IFM) from Météo France measures the risk of fire. It is real from 20 and strong from 30. Between 1989 and 2008, only the…
This article is for subscribers only. You have 62% left to discover.
Want to read more?
Unlock all items immediately. Without engagement.
Already subscribed? Login