2 degrees. That is the ‘magic figure’ of global warming, a temperature that should not be exceeded if we want to avoid disastrous consequences of climate change that, as things are, is already unstoppable. However, according to a new report just presented by the Intergovernmental Panel on Climate Change (IPCC), we should be more ambitious and lower the limit temperature to 1.5 ° C.
“Limiting global warming to 1.5 ° C instead of 2 ° C would reduce problematic impacts on ecosystems, human health and well-being, and facilitate the achievement of the United Nations Sustainable Development Goals,” he said. Priyardarshi Shukla, Co-Chair of IPCC Working Group III.
The report highlights a number of climate change impacts that could be avoided with this 1.5 ° C limit. For example, in 2100 the rise in global sea level would be 10 cm lower , and the probability that the Arctic Ocean would be ice-free in summer would be once per century with global warming of 1.5 ° C, versus a minimum of once per decade with one of 2 ° C. In addition, coral reefs would decrease by between 70% and 90%, compared to 100% in the 2 ° C increase scenario.
“One of the fundamental messages thrown forcefully by the report is that we are already experiencing the consequences of global warming of 1 ° C, with more extreme weather conditions, rising sea levels and a waning sea ice in the Arctic, among others. changes, “said Panmao Zhai, Co-Chair of IPCC Working Group I.
Are we ready to face the challenge?
“Limiting warming to 1.5 ° C is possible according to the laws of chemistry and physics, but this would require unprecedented changes,” explained Jim Skea, Co-Chair of IPCC Working Group III.
These changes mean fast and far-reaching transitions in the fields of energy, industry, construction, transport, agriculture and cities, and global net emissions of carbon dioxide would need to decrease, by 2013, about 45% from 2010 levels , and will continue to decline to “net zero” by 2050.
“The good news is that some types of measures that would be needed to limit global warming to 1.5 ° C are already taking place around the world, but they would need to be accelerated,” said Valerie Masson-Delmotte, Co-Chair of the Working group I.
As part of the decision to adopt the Paris Agreement, the IPCC was invited to prepare, in 2018, a special report on the impacts of global warming of 1.5 ° C relative to pre-industrial levels and the corresponding trajectories that they should follow. global greenhouse gas emissions. This is also the first in a series of special reports that will be evaluated in the coming years and in 2019 the “Special Report on Oceans and the Cryosphere in a Changing Climate” and “Climate Change and the Earth” will be published.
