Studies of the climate millions of years ago suggest global warming could get much worse than models say
Can we trust these “proxy” models?
The world is clearly warming. Climate models tell us why. As fossil fuels burn, Carbon Dioxide or CO2, sequestered in the ground for millions of years, is released. Even though it makes up a tiny fraction of the atmosphere, like a drop of cyanide in a cup of tea, CO2 is a poison pill for the climate. Increases of 100–200 parts per million or ppm can have catastrophic impacts.
To understand exactly how catastrophic, we turn to models which show how much the world will warm for a given increase of CO2.
This is far from straightforward, but our current models do a very good job of predicting the increase in temperatures that have been observed over the last 30 years or so.
Warming doesn’t only happen in isolation however. It impacts ocean currents and melts sea ice. Meanwhile, over time we make other changes that affect the climate not related to CO2.
We have lately seen climate models failing. For example, 2023 was much hotter than the models predicted by about 0.2…
