Video: Why net zero (and what is it?)

"There is no way we are going to be able to ban the entire world from using fossil fuels in time to meet our climate goals," warns Professor Myles Allen, the Oxford expert credited with first demonstrating, 15 years ago, the need for net-zero carbon dioxide emissions to stop global warming.

A physicist, Professor Allen is Professor of Geosystem Science in the Oxford's Environmental Change Institute and Director of the Oxford Net-Zero initiative, informing effective and ambitious climate action among those setting net-zero targets in institutions, corporations and governments across the globe.

He says investment is urgently needed into safer, permanent CO₂ disposal, to reduce the burden of greenhouse gases in the atmosphere and limit warming. While planting trees and restoring ecosystems has a vital role to play, he warns, "We can't keep turning rocks into trees forever."