The Paris 2015 climate agreement is now officially in force. The stated goal of the agreement is to limit global warming to 2 degrees Celsius (3.6 degrees Fahrenheit) or ideally 1.5 degrees Celsius. In order to limit global warming to a maximum of 2 degrees, coal, oil and gas must be mostly phased out as energy sources by 2050 - to achieve the 1.5 degree target, this would need to happen even earlier.
In order to limit global warming to 1.5 or 2 degrees, according to the United Nations Framework Convention on Climate Change (UNFCCC), countries' reduction targets submitted to date are not sufficient.
Even if all targets were achieved, according to calculations by the Potsdam Institute for Climate Impact Research (PIK), the Earth temperature would probably rise by 2.4 to 2.7 degrees by the end of this century.
A temperature increase of 1.5 degrees Celsius and sea levels would probably rise by "only" 40 centimeters by 2100. But a temperature increase of 2 degrees could mean by 2100 sea levels would be about 50 centimeters higher than today, and through ongoing ice melt from 1.5 to 4 meters higher by 2300. This would have devastating consequences for coastal regions around the world. The Netherlands, Bangladesh, Venice, New York, Tokyo, Sydney, Mumbai and London would all be hard hit.
Droughts, extreme storms and crop failure are further consequences.