Judging by the latest opinion polls, the public is ripe for some green austerity. Ipsos Mori says that 85% of Britons are concerned about climate change, with 52% admitting they are very concerned. These are the highest figures since the pollster started tracking opinion in 2005. Given the spate of extreme weather-related events, and the pictures of the torching of the Amazon rainforest, such concern is both logical and predictable. In this country, the climate deniers have been put to flight.

What the polls don’t show is whether the public is willing to translate this concern into action; whether similar levels of concern are present in less prosperous parts of the world; and whether it is possible to translate individual concerns into collective political action. Here, the message is a lot more mixed. The furore over the Duke and Duchess of Sussex’s private jets are a case in point. People don’t like being lectured to, particularly when those doing the lecturing fail to live by their own ethical code.

Emmanuel Macron wants the future of the Amazon rainforest to be top of the agenda at the meeting of the G7 he is hosting this weekend in Biarritz, but this is an empty gesture. There is not the remotest possibility of the G7 doing anything to rein in the activities of Brazil’s rightwing president, Jair Bolsonaro. Indeed, Macron’s own experience shows how hard it is to translate a desire to curb carbon emissions into practical action. The French president said making driving more expensive was a price worth paying in the fight against global heating but faced nationwide protests from the yellow vest movement. For the gilets jaunes, the immediate threat to their livelihoods mattered more than the long-term threat posed by the climate crisis.

What Macron failed to grasp was that winning this battle first means winning the battle for hearts and minds, not least by countering the impression that tackling global heating is a luxury only the better off can afford or that going green means being miserable. The success of the UK’s 5p plastic bag levy is a classic example of how nudge economics can work. Plastic bags have not been banned: consumers simply have to think about whether they are actually prepared to pay for one. The message is that consumers respond to signals: it is not always necessary to ban things.

Despite receiving a bloody nose, Macron is right when he says the climate crisis is a global problem requiring a global response. But securing international agreement is not going to be easy, in the main because the biggest increases in emissions are coming from countries where governments put a higher priority on poverty reduction than they do on safeguarding the environment.

Sales of meat and dairy products are rising fast in China because rapid growth means households can afford fridges. In the grand scheme of things, that matters a lot more to global heating than universities banning beef from their canteens.

‘China and India have much lower rates of car ownership than countries in the west, but as they grow richer their new middle classes will inevitably seek to emulate western consumers.’ Photograph: Xavier Galiana/AFP/Getty Images

China and India currently have much lower rates of car ownership than countries in the west, but as they grow richer their new middle classes will inevitably seek to emulate western consumers. The number of cars per thousand people are as follows: the US, 811; the UK, 471; China, 179; India, 22. There are 2.8 billion people in China and India. Do the maths. Africa accounted for one in five of the world’s live births in the 1990s, but by the end of the next decade it will be one in three. Demand for energy will soar as the population rises.

All of which makes the case for a global green Marshall plan to finance the transfer of low-carbon technology to poorer parts of the world look pretty compelling. The US pumped billions of dollars into the reconstruction of western Europe after the second world war to secure markets for US exporters and to discourage the spread of communism. Enlightened self-interest is required again today. If rich countries provided the financial resources to transfer low-carbon technology to the poorer parts of the world, there would be three clear benefits to the west: lower carbon emissions, fewer economic migrants and bigger markets for green goods.

Donald Trump is no Harry Truman and US participation in a green Marshall plan will have to await a change of personnel in the White House. But Elizabeth Warren, one of the leading Democrats in the presidential race, is a fan. However, even as we wait for international agreement, there are low-hanging fruit to be picked. About one-sixth of carbon emissions in the UK come from residential property, largely as a result of old-fashioned and inefficient central heating. It represents a bigger contribution to global heating than meat-eating or flying.

A drastic cut in carbon emissions from homes requires two things: better insulation and the replacement of gas-fired heating with the latest technology – heat pumps and hydrogen boilers. This will not be cheap; few households have the money to pay for the new kit, and making them pay for it through higher energy bills would be unpopular.

The independent Committee on Climate Change said putting hydrogen boilers and electric heating into every home would cost tens of billions a year, and if this is to happen quickly – as it should – the government will have to foot the bill. It could do this in two ways: by taking advantage of historically low interest rates to float green bonds – something the German government is planning – or by channelling money created by the process known as quantitative easing into environmental projects.

Retrofitting homes so that energy does not leak out of badly insulated walls and roofs means lower energy bills and the prospect of well-paid, secure jobs in every part of the country – and would make public engagement with the climate crisis easier to sustain.

• Larry Elliott is the Guardian’s economics editor