Almost 60 years ago, I suggested our planet self-regulated like a living organism. I called this the Gaia theory, and was later joined by biologist Lynn Margulis, who also espoused this idea. Both of us were roundly criticised by scientists in academia. I was an outsider, an independent scientist, and the mainstream view then was the neo-Darwinist one that life adapts to the environment, not that the relationship also works in the other direction, as we argued. In the years since, we have seen just how much life – especially human life – can affect the environment. Two genocidal acts – suffocation by greenhouse gases and the clearance of the rainforests – have caused changes on a scale not seen in millions of years. 

For billions of years the Earth’s surface temperature has been determined mainly by the radiant heat coming from the sun. This energy increased over time because it is the nature of stars like the sun to increase their heat output as they grow older. But temperatures on Earth remained relatively stable thanks to Gaia: forests, oceans and other elements in the the Earth’s regulating system, which kept the surface temperature fairly constant and near optimal for life.

The global warming that concerns all of us, and which will be discussed this week in Glasgow, includes a great deal of extra heating that comes as a consequence of extracting and burning fossil fuels since about the middle of the 19th century. That releases methane, carbon dioxide and other gases into the atmosphere. They absorb radiant heat and stop it escaping from Earth. This is what causes global warming.

Warnings that once seemed like the doom scenarios of science fiction are now coming to pass. We are entering into a heat age in which the temperature and sea levels will be rising decade by decade until the world becomes unrecognisable. We could also be in for more surprises. Nature is non-linear and unpredictable, never more than at a time of transition. 

My fellow humans must learn to live in partnership with the Earth, otherwise the rest of creation will, as part of Gaia, unconsciously move the Earth to a new state in which humans may no longer be welcome. The virus, Covid-19, may well have been one negative feedback. Gaia will try harder next time with something even nastier.