Why 2ᵒ? In the 1970s, an economist and professor of Yale, named William Nordhaus, was the first to theorize that warming of global temperatures more than 2°C, as compared to the pre-industrial era could cause the climate to dangerously move into limits that humans were completely unfamiliar with, essentially changing the world as we know it. However, this theory was not seen to be important at the time. Rising temperatures will destroy plant and animal habitats, and reduce yields of important food crops. More people will be exposed to the ravages of flooding and drought.
The graphic above gives a good idea of the impact of a global temperature increase. These impacts vary by country, by region, and by locality. One thing is certain: certain peoples are more vulnerable to the effects of climate change . For example, people living on islands, such as Tuvalu and the Marshall Islands, are experiencing erosion that have slowly been eating away at the island as a whole. The Pacific island of Kirbati has a worst-case evacuation plan due to climate change. Beijing, where cars produce so much pollution that the air turns a morbid brown, is essentially exposing citizens to a slow-acting poison. Areas affected by severe drought experience food and economic insecurity. According to the Global Drought Information System, in Spain, wine production has dropped to 40.6 hectoliters in the southern part of the country most impacted by the drought; in Ethiopia, roughly 8.2 million people need food assistance due to the drought; and, water tanks and food are being sent to indigenous people along Guyana’s border with Brazil and Venezuela as the government expects the El Nino to extend the drought into next year. Hunger and undernourishment make people, especially children, more susceptible to disease.
There are natural causes of global warming. As I posted before, the earth is sweating because excess heat cannot escape and we can't open a window to release it. It just hangs around like a bad smell. Literally.
And then there are anthropogenic (man-made) causes of global warming. This is the part we have under our control. Reducing our reliance on fossil fuels to power our lives will make a huge contribution to meeting the 2ᵒ goal. That does not just mean enacting laws that industry and agriculture must follow (although that does help). It also means we need to change our attitudes about energy and adapt our skills to living perhaps differently with alternative energy sources. Think of really good public transportation systems to go both short and long distances instead of taking a car.
Links:
https://dejusticiablog.files.wordpress.com/2015/08/climatechange.png
http://www.buzzle.com/articles/what-is-the-2degree-climate-change-target.html
http://www.motherjones.com/environment/2015/11/2-degrees-will-change-world-paris-climate-change
http://mic.com/articles/92751/an-entire-island-nation-is-preparing-to-evacuate-before-it-sinks-into-the-ocean#.e7s4wdVOG
http://www.drought.gov/gdm/current-conditions
https://dejusticiablog.files.wordpress.com/2015/08/climatechange.png
http://www.buzzle.com/articles/what-is-the-2degree-climate-change-target.html
http://www.motherjones.com/environment/2015/11/2-degrees-will-change-world-paris-climate-change
http://mic.com/articles/92751/an-entire-island-nation-is-preparing-to-evacuate-before-it-sinks-into-the-ocean#.e7s4wdVOG
http://www.drought.gov/gdm/current-conditions