"Some of the world's top climate scientists have concluded that global warming is likely to reach dangerous levels unless new technologies are developed to remove greenhouse gases from the atmosphere."

"The United Nations' Intergovernmental Panel on Climate Change (IPCC) says pledges from the world's governments to reduce greenhouse gases, made in Paris in 2015, aren't enough to keep global warming from rising more than 1.5 degrees Celsius (2.7 degrees F) above pre-industrial temperatures."