In this document, UN climate experts note that the impacts of climate change will accelerate, and become palpable well before 2050. Water scarcity, exodus, malnutrition, extinction of species... Life on earth as we know it will inevitably be transformed by climate change when children born in 2021 will be 30 years old, or even earlier, warns a draft report of the Intergovernmental Panel on Climate Change (IPCC) of the United Nations (UN), the content of which was unveiled, Wednesday, June 23 , by Agence France-Presse.

Whatever the rate at which greenhouse gas emissions are reduced, the devastating impacts of global warming on nature and the humanity that depends on it will accelerate, say hundreds of scientists attached to the IPCC, and become painfully palpable well before 2050.
Life on earth can recover from major climate change by moving towards new species and creating new ecosystems,"notes the 137-page technical summary. Humanity cannot. »

The draft report drafted by the IPCC oscillates between an apocalyptic tone and the hope offered to men to change their destiny through immediate and drastic measures. The full evaluation report (4,000 pages), much more alarmist than the previous one in 2014,is intended to inform political decisions. Although its main conclusions will not change, it will not be officially published until February 2022, after its approval by consensus by the 195 member states. Too late, however, for the crucial international meetings on climate and biodiversity scheduled for the end of 2021, some scientists note.

Risk of "irreversible impacts" above the 1.5°C threshold
Among its most important conclusions is a lowering of the threshold beyond which warming can be considered acceptable. By signing the Paris Agreement in 2015, the world committed to limiting warming to 2°C compared to the pre-industrial era, if possible to 1.5°C. Now, the IPCC estimates that exceeding the 1.5°C threshold of rising temperatures could already lead, "gradually, to serious consequences, for centuries, and sometimes irreversible". And according to the World Meteorological Organization, the probability that this threshold of 1.5 °C over one year will be exceeded as early as 2025 is already 40%.

"The worst is yet to come, with implications for the lives of our children and grandchildren far more than ours,"says the IPCC, as awareness of the climate crisis has never been more widespread.

The climate has already changed. While the rise in average temperatures since themid-nineteenth century has reached 1.1°C, the effects are already serious and will be increasingly violent, even if CO2 emissions are curbed. And living beings – human or not – who are the least to blame for these emissions are the ones who will suffer the most. For some animals and plant varieties, it may even be too late: "Even at 1.5°C, living conditions will change beyond the ability of some organisms to adapt,"the report says, citing coral reefs, on which half a billion people depend.

Among the species in reprieve are the animals of the Arctic, a territory that is warming three times faster than the average. On the spot, ancestral lifestyles, of peoples living in close connection with the ice, could also disappear.
Up to 80 million more people will go hungry
Agriculture, livestock, fisheries, aquaculture... "In all food production systems, sudden losses are increasing,"the report also observes, pointing to the vagaries of the climate as the "main driver". At this stage, however, humanity is not equipped to cope with the certain deterioration of the situation. "Current levels of adaptation will be insufficient to address future climate risks,"the IPCC warns.

Even if the increase is limited to 2°C, up to 80 million more people will go hungry by 2050 and 130 million could fall into extreme poverty within ten years. In 2050, hundreds of millions of inhabitants of coastal cities will be threatened by more frequent waves-submersion, caused by rising sea levels, which in turn will lead to significant migrations. With an increase limited to 1.5 °C, in cities, an additional 350 million inhabitants will be exposed to water shortages, 400 million beyond 2 °C. And with this extra half degree, 420 million more people will be threatened by extreme heat waves. "Adaptation costs for Africa are expected to increase by tens of billions of dollars a year beyond 2°C," the report predicts. We still have to find this money. The text also emphasises the danger of cascading effects. Some regions (eastern Brazil, Southeast Asia, central China) and almost all coastal areas could be hit by three or four simultaneous weather disasters, or even more: heatwave, drought, cyclone, fire, flood, mosquito-borne diseases... And we must also take into account the amplifying effects of other human activities harmful to the planet, notes the report: destruction of habitats, overexploitation of resources, pollution, spread of diseases...

"The world faces complex intertwined challenges,"comments Nicholas Stern, a climate economics expert who is not involved in the report. "Unless we face them at the same time, we are not going to raise any of them,"he said. Not to mention the uncertainties surrounding the "tipping points",key elements whose substantial modification could lead the climate system towards violent and irremediable change. Above 2°C of warming, the melting of the Greenland and West Antarctic ice caps (which contain enough water to cause sea level rise of 13 metres) could, for example, lead to a point of no return, according to recent work. This is why "every fraction of a degree counts",insists the IPCC, while another breaking point could see the Amazon – one of the lungs of the planet with the oceans – transformed into a savannah.In the face of these systemic problems, there is no single miracle cure. On the other hand, a single action can have cascading positive effects. For example, the conservation and restoration of mangroves and kelp underwater forests, referred to as "blue carbon"sinks, increase carbon storage, but also protect against submersions, while providing habitat for many species and food for coastal populations.

Despite its alarming conclusions, the report thus offers a note of hope. Humanity can still direct its destiny towards a better future by taking strong measures today to curb the runaway second half of the century. "We need a radical transformation of processes and behaviours at all levels: individuals, communities, businesses, institutions and government,"the report argues. "We need to redefine our way of life and consumption." READ FURTHER FROM THE SOURCE