Humans running planet like ‘rowdy schoolchildren flying Starship Enterprise’

Professor Andrew Watson, of the University of Exeter, said humans “seized control” during the Industrial Revolution and are now turning the dials “randomly this way and that”.

If the planet’s existence was expressed as a year and it is now midnight on December 31, he said, humans arrived two hours ago and the Industrial Revolution was two seconds ago.

He said humans were not the first species to have such a major impact – and urged us to be “smarter” than the bacteria that did so more than two billion years ago.

Professor Watson was speaking at the James Lovelock Centenary conference, organised by the University of Exeter’s Global Systems Institute.

“We are now in charge of the Earth’s life support systems, whether we like it or not, and currently they are hopelessly out of balance,” he said.

“We have to learn, and quickly, how to adjust the dials such that we can keep the planet habitable.

“We have the science and we know what we need to do to keep the planetary environment within habitable bounds.

“I think myself that an indefinitely sustainable Earth system is possible with 10 billion people, maybe more, living and living well on this planet.”

But Professor Watson said humans are on a dangerous path – “following in the footsteps” of cyanobacteria, which “invented” photosynthesis between 2.7 and 3.5 billion years ago.

This produced oxygen, which was lethal to many organisms at the time and also triggered a “deep and terrible ice age lasting hundreds of millions of years”.

The climate eventually stabilised, and evolution led to species that thrived in the new oxygen-rich environment.

Professor Watson said, as these processes took millions of years, humans must act to prevent rapid change rather than relying on the Earth system to adapt.

“We just need to learn the recycling lesson that the Earth has taught us, and be wiser than the cyanobacteria were,” he said.

“Surely we can be smarter than bacteria.”