Across its long trajectory, the Keystone Pipeline project was opposed by thousands of climate activists in both Canada and the U.S.
Water quality is largely dependent on concentrations of oxygen in it and less oxygen spells trouble.
Destructive species such as the fall armyworm have already spread far and wide as a result of a warmer climate.
The males of some species can become infertile even at less extreme temperatures.
The continuous growth of greenhouse gas emissions may create new conditions, to which farmers may not be able to adapt.
African rainforests continued to function as a carbon sink even in the face of adverse climatic conditions.