Scientists can now measure the damage each new coal mine can do to people, nature

Scientists have long known every tonne of carbon dioxide matters to the climate. But governments keep approving new fossil fuel projects – even as climate change worsens.

Until now, it’s been difficult to say how much damage and extra warming a specific project will do. Fossil fuel companies – and government agencies approving their projects – have often relied on what’s known as the “drop in the ocean” defence.

While backers concede a new project will add more carbon dioxide emissions to the atmosphere, they say these are tiny compared to the global tally and that it’s almost impossible to track damage attributable to the emissions of an individual project.

This defence won’t work any more. In recent years, attribution science has advanced rapidly, allowing scientists to pinpoint the role of climate change in making disasters and extreme weather more likely.