Humanity is currently on course to double or even triple the carbon dioxide content of the Earth’s atmosphere by the end of this century.
Our current level of about 400 parts per million of CO2 is already higher than at any time during the evolutionary history of humans.
By 2100 the carbon content of the air could reach levels not seen for as long as 50 million years, pushing up global temperatures by 4 to 6 degrees Celsius (7.2-10.8 F) and transforming our planet beyond all recognition.
Even at four degrees of warming there will be a global collapse in food production due to drought and heat stress of crops in main breadbasket areas. Glacial ice will completely disappear in the Andes, Alps and substantial portions of the Himalayas. There will also be a significant rise in ocean acidification. A change in pH spells trouble for shelled marine life, including coccolithophores, which make a notable percentage of Earth’s oxygen.
The single and overriding priority for any environmentalist in the 400ppm world must be to quickly eliminate coal power.
There is no prospect whatsoever of us running out of coal – or indeed any other fossil fuel – in time to save the climate.
China has the third-largest coal reserves in the world, after the US and Russia; India the fifth-largest. At current rates of production, global coal supplies will last for 112 years, and no doubt vast new reserves still remain to be found.
What we need to do is ensure is that we put the investment in now to new forms of generation – nuclear and renewables - that in future will make coal uneconomic.
And this must surely take place first in rich countries like Britain, as poorer countries in Asia and elsewhere still rely on cheap coal to fuel their much-needed economic growth.
If the UK cannot lead the way in removing coal from its grid, then what does that say to other countries without our economic resources and infrastructure?
Mark Lynas’ new book Nuclear 2.0: Why a Green Future Needs Nuclear Power is available from Amazon.