As models could easily churn out numbers that saw atmospheric carbon dioxide go as low as one wanted, ever more sophisticated scenarios could be explored which reduced the perceived urgency to reduce fossil fuel use. People leaped to their feet, strangers embraced, tears welled up in eyes bloodshot from lack of sleep.

Given their core assumption of incremental change, it was becoming more and more difficult for economic-climate models to find viable pathways to avoid dangerous climate change.

As a side note, I think its also worth mentioning that governments have for too long said 'let the market decide' when in fact this is precisely what has led us to this point in the first place. It happens when you enter a simple formula like =5/0, or when a formula refers to a cell that has 0 or is blank, as shown in this picture. Government promised significant public spending in 2019 and committed to new policies last year, neither has yet occurred.

Clark shows that efforts to achieve the target will inevitably result in a huge hit to living standards, which will clobber the poorest hardest, and gift a massive geopolitical advantage to hostile superpowers such as China and Russia. Instead of confront our doubts, we scientists decided to construct ever more elaborate fantasy worlds in which we would be safe. Estimates of the amount of land required are as high as 3000 million hectares – twice the total amount of land currently under cultivation globally.That hasn't prevented the UK government from fixing dates in the early 2030s for banning the sale of petrol- and diesel-engined vehicles (and even of hybrid fossil-fuel/electric vehicles) and of gas boilers, and a date later this decade for banning the sale of oil-fired boilers (much used for domestic heating and hot water in rural areas).