There are 415 British MPs who don’t take climate change seriously enough. That is the number who voted to build a third runway at Heathrow earlier this week; 119 of them were Labour.

The plans sailed through Parliament, despite some vocal but limited resistance. Only 119 MPs voted against it. Most of them weren’t worried that a third runway would make it near impossible to meet the government’s carbon reduction commitments. They were concerned that the plans were London-centric and might sideline transport projects in the north.

Government figures predict that the third runway will mean Heathrow's CO2 emissions rise by 7.3 million tonnes a year by 2030 – more than Cyprus’s annual emissions. Aviation emissions have to be down to 2005 levels by 2050 if overall emissions are going to be cut by 80 per cent. Higher aviation emissions would place an unreasonable burden on other sectors. (Of more immediate, local concern, a vote for a new runway is a vote for increasing toxic air pollution.)

If the UK were serious about meeting its responsibilities on climate change, not only would we not be building another runway anywhere in the country, we would be taking steps to reduce the number of domestic flights that take off and land each day. But the government, despite teetering on the edge of collapse, was able to unite most of Parliament around the disastrous Heathrow plans.

You might expect nothing less from a Government that has overseen a fall in investment in clean energy over the past two years, and decided not to give any subsidies to the Swansea Bay tidal lagoon. But why did Labour MPs get this so wrong?

With an environmentally conscious left-winger as leader, the Labour Party’s official position was to oppose the runway. But a significant chunk of MPs, unhampered by a whip they would probably have rebelled against, along with most of the labour movement, were thinking more about the thousands of new jobs it would create than about the environment. Jobs matter; of course they do: food banks and rising in-work poverty figures are signs that something is deeply wrong with the economy. But those jobs, many of them temporary, won’t mean anything as the planet folds in on itself.

Climate change is a product of capitalism. The global economy is obsessed with growth. Multinational corporations move around the world, mining, fracking and drilling, uprooting local communities, selling fossil fuels and propelling the destruction of the planet. And it’s in this economy that airport owners are encouraged to expand, ‘regardless of whether it makes sense’ (that’s in the words of the Financial Times). For internationalism to be meaningful, people on the left who voted for the runway would have to be more concerned that the people who stand to suffer the most and the soonest from climate change are people in low-income countries that have contributed to it the least.

The environment is not an abstract thing that exists somewhere else, in a bubble removed from our day-to-day lives. We live in the environment; that’s what the word means. But this week British politicians showed complete disregard for it. Whether the runway is built or not (local councils and environmental groups are still opposing it), in British politics, as elsewhere, there is too much reckless, short-term thinking. It’s utterly shameful.