5C is the temperature increase above pre-industrial levels we are heading for if we follow our path of limited or no climate policy.
2C is the temperature increase above pre-industrial levels that most countries around the world have agreed would prevent dangerous climate change.
This journey will describe how the energy system must change if we go from 5C to 2C
Related
The awful truth about climate change no one wants to admit http://www.vox.com/2015/5/15/8612113/truth-climate-change
The Microbes That Are Eating The Thawed Permafrost http://www.theecologist.org/News/news_round_up/2869575/thawing_arctic_carbon_threatens_runaway_global_warming.html
