As a verdict on the climate crimes of humanity, the new Intergovernmental Panel on Climate Change report could not be clearer: guilty as hell.

The repeatedly ignored warnings of scientists over past decades have now become reality. Humanity, through its actions, or lack of action, has unequivocally overheated the planet. Nowhere on Earth is escaping rising temperatures, worse floods, hotter wildfires or more searing droughts.

The future looks worse. “If we do not halt our emissions soon, our future climate could well become some kind of hell on Earth,” says Prof Tim Palmer at the University of Oxford.

This would be the sentence for these climate crimes, but it has yet to be passed down. The world can avoid the harshest punishment, but only just. Immediate repentance for the delays that have brought the world to the brink is required in the form of immediate and deep emissions cuts.

The key aspect of the IPCC report is that the 42-page summary is agreed, line by line, by every government on the planet, with the scientists vetoing any politically convenient but unscientific proposal.

As a result, governments that continue to fail to take action have nowhere left to hide – the crystal-clear report has bust all of their alibis. 

Every choice made now matters. Helen Clarkson, the CEO of the Climate Group, which represents 220 regional governments and 300 multinational businesses, covering 1.75 billion people and 50% of the global economy, says: “Every decision, every investment, every target, needs to have the climate at its core.”

The gravity of the situation laid out in the report blows away blustering over the supposed costs of climate action. In any case, not acting will cost far more. “It’s suicidal, and economically irrational to keep procrastinating,” says Prof Saleemul Huq, director of the International Centre for Climate Change and Development at the Independent University, Bangladesh.

For those governments and businesses that still chose inaction, the IPCC report may well end up being used as key evidence against them in real courtrooms. “We’ll be taking this report with us to the courts,” says Kaisa Kosonen at Greenpeace.

“By strengthening the scientific evidence between human emissions and extreme weather the IPCC has provided new, powerful means to hold the fossil fuel industry and governments directly responsible for the climate emergency,” she says. “One only needs to look at our recent court victory against Shell to realise how powerful IPCC science can be.”