Fifty-one billion and zero – the two numbers Bill Gates says you need to know about climate.
Solving climate change would be “the most amazing thing humanity has ever done”, says the billionaire founder of Microsoft.
By comparison, ending the pandemic is “very, very easy”, he claims.
Mr Gates’s new book, How to Avoid a Climate Disaster, is a guide to tackling global warming.
Don’t underestimate the scale of the challenge, he told me when we spoke last week.
“We’ve never made a transition like we’re talking about doing in the next 30 years. There is no precedent for this.”
Fifty-one billion is how many tonnes of greenhouse gases the world typically adds to the atmosphere each year.