The G20 nations provide four times more public financing to fossil fuels than to renewable energy, a report has revealed ahead of their summit in Hamburg, where Angela Merkel has said climate change will be at the heart of the agenda. The authors of the report accuse the G20 of “talking out of both sides of their mouths” and the summit faces the challenge of a sceptical US administration after Donald Trump pulled out of the global Paris agreement. The public finance comes in the form of soft loans and guarantees from governments, and, along with huge fossil fuel subsidies, makes coal, oil and gas plants cheaper and locks in carbon emissions for decades to come. But scientists calculate that to keep global warming below 2C, most fossil fuel reserves must be kept in the ground, requiring a major shift of investment to clean energy.