To illustrate what this could mean in reality, WWF has developed 2°C scenarios for 3 regions:
A 2°C rise would lead to a minimum 3.2°C temperature increase in the Arctic, and possibly twice that. The major reason for this is the melting of the polar ice. Previously white ice reflected much of the sunlight back into space, but it is now replaced by dark water which absorbs much more heat. In consequence, even with a 2°C temperature rise the Arctic will be unrecognizable, with summers featuring no or almost no ice. Traditional lifestyles are likely to become very hard to maintain. Species like the polar bear and migrating birds will find their habitats deteriorating or even destroyed.
Annual rainfall could decrease by 20% over the southern Mediterranean and summer rains could decrease by 30% in the northern Mediterranean alone. There will be increased problems with water supply for agriculture and people especially in North Africa, Spain, France and Italy. More heatwaves will mean a serious increase in forest fires, with some occurring all year round in parts of the Mediterranean. These heatwaves could also discourage summer tourism.
Important tree species in Ontario – black spruce and sugar maple, the national symbol of Canada – will be forced northwards and it is unclear whether they will be able to adapt. Timber will have to come from younger, smaller trees. A 2°C rise will also impact on Canadian fisheries and could firmly shut the door on the already endangered Atlantic salmon. The small but voracious Asian shore crab is one example of an invading species from the south which will put increased pressure on native shellfish and crab, and the fisheries that rely on them.