A new United Nations [1] report warns that progress toward prosperity in the world’s poorest regions will be reversed unless rich countries promptly begin curbing emissions linked to global warming [2] while also helping poorer ones leapfrog to energy sources that pollute less than coal and oil.

The world’s poorest regions will also need much more help [3]than has been provided to adapt to climate changes that are already unfolding, said the authors of the study, the United Nations’ annual Human Development Report.