What will happen in the future?

Some commentators, including the GWPF, adopt a so-called ‘lukewarmist’ position, arguing that climate change will not be too bad so there is no need to stop using fossil fuels. They point to beneficial effects such as 'global greening' in which plant growth is boosted by the extra carbon in the air.

Others have claimed humanity is plunging headlong towards catastrophe and possibly even a future in which a tiny band of survivors cluster around the last remaining habitable territory near the poles.

Both groups are at odds with the science.

As Professor Tim Palmer, an Oxford University physicist who has worked on reports for the Intergovernmental Panel on Climate Change (IPCC), explained in a recent talk at the Royal Society, the ‘scientific consensus’ on climate change is that it could be anything between those two extremes.

According to computer models, developed using mathematics, the laws of physics and the best available knowledge, the world could be on course for between about 1.5C and more than 5C of warming as a result of the doubling of atmospheric carbon dioxide. So far it has risen from about 280 parts per million – a level that had remained fairly constant from the end of the last Ice Age to the 1800s – to more than 400ppm today.

“When we talk about scientific consensus, I would say it’s basically about this [temperature] distribution, it’s not individual predictions,” Professor Palmer told the Royal Society.

But, according to the models, there is a much higher probability of going beyond 2C of warming, than staying below this point, often regarded as when climate change becomes particularly ‘dangerous’.

And, as Professor Palmer also pointed out, there is also “a non-negligible probability of 5C or more, which would be utterly catastrophic”.