“Without further commitments and action to reduce greenhouse gas emissions, the world is likely to warm by more than 3° above the preindustrial climate. Even with the current mitigation commitments and pledges fully implemented, there is roughly a 20 percent likelihood of exceeding 4° by 2100. If they are not met, a warming of 4° could occur as early as the 2060s.

Thus, while the global community has committed itself to holding warming below 2° to prevent “dangerous” climate change, and Small Island Developing states (SIDS) and Least Developed Countries (LDCs) have identified global warming of 1.5° as warming above which there would be serious threats to their own development and, in some cases, survival, the sum total of current policies—in place and pledged—will very likely lead to warming far in excess of these levels. Indeed, present emission trends put the world plausibly on a path toward 4° warming within the century.”