Many of those MPs who marched through the lobbies to vote in favour of expanding Heathrow this week – Labour parliamentarians among them – will speak eloquently, if pushed, about the threat of climate change. Unfortunately their words have been rendered meaningless by their vote. You cannot truly fear the impact of climate change and then opt to raise Heathrow’s emissions by 7.3m tonnes of carbon dioxide – a figure that, as Greenpeace notes, is equivalent to the annual total output of Cyprus.

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The talk of promoting jobs and economic growth that swirled around the vote is self-destructive short-termism. According to the World Wide Fund for Nature, the floods, droughts and heatwaves that climate change will bring will cost the economy tens of billions of pounds, as well as hundreds of thousands of jobs, by 2050. By focusing on high-carbon infrastructure as a means to create jobs, we distract ourselves from exploring how we can create hundreds of thousands of skilled, well-paid, secure jobs in the renewable energy sector, as Germany has done.

A disastrous vote then, but also one that offers a revealing insight into what the Tory approach to Brexit means. According to her spokesman, Theresa May believes that expanding Heathrow “sends out an important message about global Britain and making the most of the opportunities which lie ahead of us”.

The airport’s chief executive, John Holland-Kaye, echoed the government rhetoric, lauding a “real Brexit bonus”. Clearly a hard Tory Brexit – grievously damaging economic relations with our nearest trading bloc – means a Trumpian hell-for-leather dash for growth at any cost. Who benefits from that growth, or what it means for the environment, are not high-priority questions. Indeed, on the same day as the Heathrow vote, the government rejected plans for a £1.3bn tidal lagoon in Swansea Bay, another potential source of jobs and growth that would help to counter global warming.

As the Committee on Climate Change (CCC) warns today, the Tory obsession with scrapping what David Cameron infamously called “green crap” will saddle us all with higher costs in the future. As for the “green Brexit” cynically trumpeted by Tory leadership wannabe Michael Gove, that was clearly yesterday’s soundbite.

Play Video 0:40 MPs vote in favour of third runway for Heathrow – video

Yes, climate change can seem like an abstraction – too technical, too distant. I admit my own brain tends to fade out when I hear about it. History may judge that one of the most disastrous consequences of the financial crash was that it distracted from the imperative of dealing with climate change: here-and-now crises of falling living standards, a lack of secure jobs and public sector cuts suddenly became more pressing and urgent.

Brexit, too, sucks in all the political oxygen, starving other crises of attention and giving the Tories a pretext to bet the farm on making departure from the EU look like it can work. But our government is legally bound to cut emissions by 80% by 2050, meaning our aviation emissions must be at the levels they were in 2005 – 37.5m tonnes – by mid-century. A Department for Transport report reveals we will already have hit 43m tonnes by 2030 after Heathrow expansion. Because we are signatories to the Paris agreement, we are obliged to limit a rise in global temperatures to well below 2C. But as Lord Deben – a former Tory minister and chair of the CCC – put it to the transport secretary, Chris Grayling, regarding Heathrow expansion: “We were surprised that your statement to the House of Commons … on 5 January 2018 made no mention of either of these commitments.”

If we’re going to abide by our targets, as well as expand Heathrow, that means deeper cuts in emissions in other parts of the economy. Where? As Deben has wryly noted, the CCC “has limited confidence about the options [for achieving the compensatory cuts needed]”.

Who will benefit most from this expansion? More than half of Britons don’t fly at all in any given year. Just 15% of Britons – disproportionately the most affluent – take more than 70% of all flights. House of Commons research suggests that having a second home and a household income of more than £115,000 are the best indicators of whether or not you are a frequent flyer. And as Labour’s Clive Lewis points out, many of the beneficiaries of a bigger Heathrow will be international transfer passengers whose money will never even make it into the UK economy (except maybe by buying the odd bottle of whisky in duty free). Is bulldozing communities, increasing noise pollution and noxious fumes, and above all accelerating climate change, a price worth paying for that?

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Consider the challenges we must confront. Greenpeace’s chief scientist, Doug Parr, tells me: “We’re looking at scale-ups of water shortages, heatwaves and extreme weather across the world.” The Tories might laud their approach to Brexit as paving the way for Britain’s resurrection as a global trading nation. But the damage inflicted by climate change on our trading partners means we will suffer too. The impacts in Britain will be felt on agriculture, road and rail, electricity, water and sewage systems – all hit by rising temperatures. Look at the fire on Saddleworth Moor: other factors are at play, such as how the land is managed. But we can be sure that climate change will increase the likelihood of such disasters.

This week, our political elite sent a message to the future that will not be forgotten. They could have championed an ambitious route: one that invests in skilled green jobs as part of a new just and sustainable order. Instead a decision was taken to play Russian roulette with our planet for short-term, limited gain. In two generations’ time, what will those yet to be born make of a reckless decision taken when there was still time to act in the face of coming catastrophe? The Heathrow vote was a wanton act of vandalism and we will all suffer from this particular “Brexit dividend”.

• Owen Jones is a Guardian columnist