The world must prepare for the “climate endgame” to better understand and plan for the potentially catastrophic effects of global warming that governments have yet to consider, scientists warned on Tuesday.
Climate models, which can predict the extent of global warming in relation to greenhouse gas emissions, are becoming more sophisticated and provide policymakers with an accurate trajectory for global temperature increases.
What is less well understood is the cascading impact of certain events, such as crop failures and loss of infrastructure due to extreme weather events, which are more likely to occur with each degree of warming.
Researchers from the University of Cambridge and the Potsdam Institute for Climate Impact Research (TO CHOOSE) outlined what is currently known about the “catastrophic consequences” and found gaping gaps in knowledge.
In an article for the journal Proceedings of the National Academy of Science, they proposed an international research agenda to help governments plan “from bad to worse.”
These include four major areas of concern — what the authors have called the “four horsemen” of climate change: hunger and malnutrition, extreme weather, conflict, and vector-borne diseases.
“The irreversible and potentially catastrophic risks posed by human-induced climate change must be factored into our plans and actions,” said Johan Rockstrom, director of PIK and co-author of the study.
He said that as more research is being done on Earth’s climate tipping points, such as the irreversible melting of ice caps or the transformation of the Amazon rainforest from a carbon sink into a source, there is an increasing need to consider high-risk scenarios in climate change. modeling.
“The key is to do the math of the disaster to avoid it,” he said.
– “Inadequate Caution” –
The authors pointed out that subsequent UN climate science reports have largely focused on the projected impacts of 1.5 to 2 degrees Celsius warming, and have largely overlooked the possibility of more extreme temperature increases.
According to government plans, the Earth’s temperature will increase by 2.7°C this century, far from the 1.5°C limit set by the 2015 Paris Climate Agreement.
The study found that the scientific bias “to err on the side of the least drama” has led to a lack of attention to the potential impacts of 3 degrees Celsius or more of warming.
“This warning is understandable, but it does not match the risks and potential damage caused by climate change,” the statement said.
In addition, it is well known that risk assessments for so-called low-probability high impact events are difficult to adapt to long-term climate modeling.
Researchers have calculated that by 2070, areas of extreme heat – with an average annual temperature of more than 29 degrees Celsius – could cover two billion people.
They warned that temperatures pose a serious risk of multiple “breadbasket failures” due to the drought that has gripped Western Europe and heatwaves such as the one that hit Indian wheat crops in March/April.
The team called for a special UN science report on “catastrophic climate change scenarios,” similar to its 2018 report on 1.5°C warming.
“We need to get serious about understanding the serious risks involved in moving our planet into unknown territory,” said Joary Rogel, director of research at Imperial College London’s Grantham Institute, who was not involved in the study.
“Exploring these edge cases means we can better prepare, including getting more serious about reducing emissions now.”