A group of the world’s leading thinkers on climate change have issued an urgent call for the world to reach peak greenhouse gas emissions by 2020, as global leaders prepare for a gathering in Germany next month.

The group, led by former United Nations climate chief and Paris Agreement architect Christiana Figueres, warns in a piece published in the journal Nature that the planet could face unsafe — and irreversible – levels of temperature increases if greenhouse gas emissions do not begin to fall by 2020. The piece calls on energy policymakers to implement policies to move the world to 30% renewable energy by 2020 and stop approving new coal-fired power plants, among other initiatives.

“There will always be those who hide their heads in the s…