What is net zero?

More than 50 countries around the world have pledged to become net zero. But what does net zero actually mean—and is it achievable? Find The Economist’s most recent coverage on climate change: Sign up to The Economist’s daily newsletter to keep up to date with our latest stories: Why do climate pledges fall short?: What are nationally determined contributions to curb climate change?: How sincere are climate pledges?: Decarbonising the world’s energy system: