In the economy as in ecosystems, one tipping point can lead on to another. Creating cascades of change throughout the global economy is perhaps the only imaginable way we could make the transition to zero emissions at the pace required. This should be the focus of climate change diplomacy throughout this decade. If enough of the world joins in, we might just have a chance.

Humanity’s situation with climate change is sometimes compared to that of a frog in a slowly boiling pot of water. Most of our climate science takes the form of prediction: telling the frog that in five minutes’ time he will be a little bit warmer. We need more risk assessment: telling the frog that the worst that could happen is he could boil to death, and that this is becoming increasingly likely over time. This approach can give a much clearer picture of the risks of climate change to human health, food security, and coastal cities.

When we study technology transitions of the past – the shifts from horses to cars, from cesspools to sewers, from traditional farming to intensive agriculture – we can see how they were enabled and accelerated by government policy. Coordinated action by groups of countries could accelerate change even more – through faster innovation, larger economies of scale, and level playing fields where needed. International cooperation of this kind could dramatically accelerate low-carbon transitions in each of the greenhouse-gas-emitting sectors of the global economy. Until now, it has barely been attempted.

Regulation has been given an unfairly bad name. As a top physicist who became an Energy Secretary and took an interest in fridges found out, the right regulation can do the opposite of what economists expect: accelerate innovation and cut costs, as well as cutting emissions.

The year 2021 saw extreme weather events outside the range of what experts had thought possible, signs of a growing acknowledgement among scientists of the need to take risk assessment more seriously, and the launch of a new initiative that might finally tell heads of government what they need to know.

At any moment in time, you can ride a bike with least effort by cycling in first gear. But if you want to ride around the block with least effort, first gear will not be ideal. By failing to distinguish between these two different situations, economists have recommended the worst possible climate change policy to governments. Contrary to their belief, emissions trading will achieve decarbonisation at maximum cost, and minimum speed.

In science, to be ‘conservative’ is to understate your findings. In insurance, it means the opposite: erring on the side of overstatement of risks. For a clear assessment of the risks of climate change, we need these two cultures to meet in the middle. This requires a separation of tasks: between those who gather information, and those who assess risk.

Traditional economics tells us that to meet policy goals, government should only do the minimum needed to fix a ‘market failure’. A new understanding shows that when the goals are innovation and change, a ‘do the maximum’ approach can be more effective. We should stop aiming to achieve ‘decarbonisation at least cost’, and instead aim to move to the clean economy at maximum gain.

The UK’s desire to prove its international relevance after Brexit, together with the COVID pandemic, produced a unique opportunity: a two-year Presidency of the UN climate talks for the country that has long been the most active in climate change diplomacy. A chance to test a new approach – after thirty years of slow progress, better late than never.

A movement is gathering to overthrow the intellectual incumbents of economics. Started by students, advanced by academics, and funded by philanthropists, until recently it has remained largely unnoticed by governments. Now the world’s largest emerging economies are starting to take an interest. For the sake of avoiding dangerous climate change, the revolution cannot come too soon.

The first twenty years of international negotiation on climate change took an approach that was guaranteed to fail: attempting to solve an immensely complex issue through a single, legally binding agreement. The history of diplomacy in trade and security shows that success requires a different approach: breaking a problem up into manageable parts, and growing agreement gradually, strengthening it as parties’ interests increasingly converge.

Neither scientists, nor economists, nor insurers, nor military planners have assessed the risks of climate change in full. Heads of government are left to guess. A clear understanding of the scale of the risks will not on its own guarantee a proportionate response. But unless we have such an understanding, we can hardly be surprised if our response is inadequate.