Imminent Climate Tipping Points

A tipping point is a critical threshold that, when crossed, leads to large, accelerating and often irreversible changes in the climate system. If the tipping point in one system is crossed, this could cause a cascade of other tipping points, leading to severe, potentially catastrophic, impacts. Scientists have identified many elements in the climate system which may have tipping points. As of September 2022, nine global core tipping elements and seven regional impact tipping elements are known. Out of those, one regional and three global climate elements will likely pass a tipping point if global warming reaches 1.5 °C. They are the Greenland ice sheet collapse, West Antarctic ice sheet collapse, tropical coral reef die off, and boreal permafrost abrupt thaw.

In a report published on January 10, 2025, the Copernicus Climate Change Service confirmed that 2024 was the warmest year on record globally, and the first calendar year that the average global temperature exceeded 1.5°C above its pre-industrial level.

NYT (April 28): The Trump administration has dismissed the hundreds of scientists & experts who had been compiling the federal government’s flagship report on how global warming is affecting the country…Since 2000, the federal government has published a comprehensive look every few years at how rising temperatures will affect human health, agriculture, fisheries, water supplies, transportation, energy production and other aspects of the US economy. It is used by state and local governments as well as private companies to help prepare for the effects of heat waves, floods, droughts and other climate-related calamities. The last climate assessment came out in 2023. Its publication is overseen by the Global Change Research Program, a federal group established by Congress in 1990 that is supported by NASA. Scientists involved in earlier climate assessments have said the report is invaluable.

During Trump’s first term, his administration tried, but failed, to derail the National Climate Assessment. When the 2018 report came out, concluding that global warming posed an imminent and dire threat, the administration made it public the day after Thanksgiving in an apparent attempt to minimize attention.

Russell Vought, the current director of the Office of Management and Budget, wrote before the election that the next president should “reshape” the Global Change Research Program, because its scientific reports on climate change were often used as the basis for environmental lawsuits that constrained federal government actions. Mr. Vought has called the government’s largest climate research unit, a division inside the National Oceanic and Atmospheric Administration, a source of “climate alarmism.”

Now why might that be? Peter Carter: “Warming is already the fastest in 485 million years (Judd, 2024); 2025 is now above record 2024 (Data NASA GISS, Copernicus); explosive surface heating by burning fossil fuels. It is insane to be just monitoring…in the most dire planetary emergency, the silence of science is deafening.”

In an April 29 report published by the University of Exeter, “Scientists evaluated the risk of tipping across 16 critical components of the Earth’s system—including the collapse of major ice sheets, the loss of tropical coral reefs, and the dieback of vast forests. Under current policies and projected warming, their most conservative estimate shows a 62% average risk of crossing one or more tipping points. However, the study also highlights that adopting more sustainable pathways with lower greenhouse gas emissions could significantly reduce this risk.” Good luck with that.