Global warming could be catastrophic for humanity, threatening the collapse of world society and, in extreme projections, human extinction. Financial crises, armed conflicts, and the spread of new infectious diseases are among the many risks cited by researchers studying the side effects of climate change, led by an international team including scientists from the University of Cambridge.
The world should prepare for the possibility of a climate apocalypse. Researchers propose an agenda to confront the worst-case scenarios, which have been little explored and carry varied implications. Some projections warn of massive loss of life, up to tens of percent of the global population.
There is reason for caution. Climate change could trigger global catastrophe. By analyzing the mechanisms behind extreme outcomes, scientists aim to spur action, build resilience, and inform policy, including emergency response planning, in the face of the climate crisis.
In a paper published in the Proceedings of the National Academy of Sciences, the authors review the current climate situation and come from groups associated with the Intergovernmental Panel on Climate Change. Their discussion centers on the term catastrophic climate change to promote further research and public awareness about the dangers of global warming.
They argue that the scientific community must rise to the challenge of understanding catastrophic climate change and its consequences, including political instability, food shortages, and systemic financial risk.
global nuclear war
As far back as 1988, the Toronto Conference highlighted the potential final consequences of climate change that might be addressed only through global nuclear war. Despite warnings decades ago, climate catastrophe remains relatively understudied and poorly understood.
Even after 30 years of effort under the United Nations Framework Convention on Climate Change, anthropogenic greenhouse gas emissions continue to rise, and so does the warmth.
At present, about 0.8% of the world’s land area experiences an average annual temperature above 29 degrees Celsius, affecting roughly 30 million people. Under future pathways with higher emissions and population growth, projections show that by 2070, around 2 billion people could live in extremely hot regions.
This troubling trend is compounded by the fact that hotspots often overlap with politically fragile states. If political stability does not improve, a belt of instability with serious consequences could form, the report warns.
Hence the call to analyze worst-case scenarios. In the authors’ view, climate change could irreversibly undermine humanity’s ability to withstand another disaster, such as nuclear conflict, unless proactive measures are taken.
The ‘four horsemen’ of climate change
Researchers identify multiple factors contributing to climate-related harm, describing the four main elements of a climate apocalypse: famine and malnutrition, extreme weather events, conflict, and vector-borne diseases. These riders are accompanied by impacts from air pollution and rising sea levels.
For this reason, the researchers outline a research agenda for catastrophic climate change focused on four key issues:
-Understand long-term dynamics and effects of extreme climate change.
-Identify climate-triggered pathways to mass morbidity and mortality.
-Explore social vulnerability, risk cascades, and how communities respond to threats.
-Synthesize results into integrated disaster assessments.
The report concludes clearly: there is substantial evidence that climate change can be catastrophic, even at modest warming. Grasping extreme risks is essential for informed decisions, including preparedness and emergency responses.
Facing a climate-accelerating future without considering worst-case scenarios would be naive at best and dangerous at worst, the authors write.
Reference note: PNAS, 2021 update on catastrophic climate change (citation format used for attribution within this article).