The world must cut CO2 emissions to zero by 2070 at the latest to keep global warming below dangerous levels and prevent a global catastrophe, the UN warns.By 2100, all greenhouse gas emissions – including methane, nitrous oxide and ozone, as well as CO2 – must fall to zero, the United Nationals Environment Program (Unep) report says, or the world will face what Intergovernmental Panel on Climate Change scientists have described as “severe, widespread and irreversible” effects from climate change.
The Unep report published on Wednesday is based on the idea that the planet has a finite ‘carbon budget’. Since emissions surged in the late 19th century, some 1,900 Gigatonnes (Gt) of CO2 and 1,000 Gt of other greenhouse gases have already been emitted, leaving less than 1,000 Gt of CO2 left to emit before locking the planet in to dangerous temperature rises of more than 2C above pre-industrial levels.
