In Chapter 2 the basic facts of global warming were introduced, based almost exclusively on the latest UN’s Intergovernmental Panel on Climate Change Report (IPCC, 2007), particularly on Working Group I’s Fourth Assessment Report on the Physical Science Basis of Climate Change (IPCCa, 2007). These facts concern changes in atmospheric constituents and in radiative forcing, in Earth’s surface and atmosphere, in snow, ice and frozen ground and in the sea level. These changes are due to global warming. The Stern Review provides key past and present facts about the drivers of global emissions’ increase. It also provides relevant key projections. These are summarized as follows (Stern Review, 2006, p. 169):
Greenhouse-gas concentrations in the atmosphere now stand at around 430ppm CO2 e, compared with only 280ppm before the Industrial Revolution. The stock is rising, driven by increasing emissions from human activities, including energy generation and land-use change.