Today’s US-China joint announcement on climate change and energy is the most important advance on the climate change agenda in many years. While the full ramifications will only be known at the climate summit in Paris in December 2015, the two largest C02 emitters have finally spoken, and most importantly, they’ve spoken together. What they’ve said gives the world a fighting chance – and no doubt the last one – for climate safety.
The situation is stark. While the world’s governments agreed back in 2009 that we need to keep global warming below 2 degrees Celsius (relative to the pre-industrial era), in order to avoid massive damages from droughts, floods, extreme heat waves, and rising ocean levels, the brutal fact remains that the world is on course for a catastrophic rise of some 4 to 6 degrees by the end of the century. To avoid catastrophe, and stay below the 2 degree upper limit, CO2 emissions from energy use need to fall very sharply by mid century, and to reach net-zero emissions (“decarbonization”) by around 2070.
In short, the world will need to get almost entirely out of the fossil fuel business in the next half century or so, except for what can be continued safely with the use of carbon capture and storage (CCS). Such a deep transformation is feasible through a combination of three main steps: massive energy efficiency; a pervasive shift to low-carbon and zero-carbon electricity (notably wind, solar, geothermal, hydro, nuclear, and CCS); and the electrification of all vehicle transport and of heating and ventilation in residential and commercial buildings.