A lot has been said about the threats that climate change poses to humans and the environment. Now, an international team has released a paper that suggests the danger of global warming is not adequately known yet.
The new work published in Proceedings of the National Academy of Sciences infers that catastrophic outcomes of climate change have not been adequately highlighted in research. It concludes that the potential of global warming to bring about human extinction is “dangerously underexplored.”
“There are plenty of reasons to believe climate change could become catastrophic, even at modest levels of warming,” said Dr. Luke Kemp, the paper’s lead author. “Climate change has played a role in every mass extinction event. It has helped fell empires and shaped history. Even the modern world seems adapted to a particular climate niche.”
The experts say the world faces the threat of horrible scenarios, including a 10% loss of its population and potentially human extinction.
Kemp and his fellow team members contend that what could happen from warming of 3 degrees Celsius or more – including allied extreme risks – has been under-researched.
The 2021 report by the International Panel on Climate Change (IPCC) indicated around an 18 percent likelihood of warming exceeding 4.5 degrees Celsius if CO2 levels in the atmosphere double those seen in pre-industrial times. The scary thing is that the planet is already midway towards those levels, according to researchers.
A review of IPCC reports, which was co-authored by Kemp and published a few months ago, noted increasing attention being given to lower temperature increases. There has been a shift of focus from high-end warming.
Earlier research that Kemp also contributed to had shown that the chances of extreme scenarios occurring have been underexplored.
In this new work, modeling showed that extreme heat could impact about two billion people by 2070. Extreme heat is described as an annual average heat level of more than 29 degrees Celsius.
What is, perhaps, more worrisome about these predictions is that areas that are expected to be impacted are not only among the most densely populated in the world but also among the most politically fragile.
“By 2070, these temperatures and the social and political consequences will directly affect two nuclear powers, and seven maximum containment laboratories housing the most dangerous pathogens,” said paper co-author Chi Xu. “There is serious potential for disastrous knock-on effects.”
Attention to dire consequences
Kemp and his collaborators want more research focus on what they term the climate endgame’s “four horsemen.” These are famine and malnutrition, extreme weather, conflict, and vector-borne diseases.
Food supply across the world is increasingly threatened by rising heat levels. Climbing temperature also increases the chance of extreme weather, which could, in turn, promote new disease outbreaks.
Climate change may increase conflicts. The experts say it could worsen “interacting threats,” including rising inequality, breakdowns of democracies, and even new devastating AI weaponry. There could also be “warm wars” between technologically-superior countries over shrinking carbon space and large-scale experiments to redirect sunlight and heat.
The team calls for a research agenda with a greater focus on the potential horrors of climate change. It wants the IPCC to devote a future report to possible catastrophic effects of global warming to spur research and increase public awareness.
Researchers say more focus needs to be given to all possible critical points within “Hothouse Earth” that could trigger disaster. These include melting permafrost that discharges methane and the loss of forests that should store carbon. Research is also needed to better understand vanishing cloud cover.
“We need an interdisciplinary endeavor to understand how climate change could trigger human mass morbidity and mortality,” said co-author Prof. Kristie Ebi.