Jeremy Corbyn’s dietary habits made headlines recently when he said he was considering going vegan. This would represent a next step for the Labour leader, who has long-been a committed vegetarian. It is welcome that Corbyn is open to having the conversation about cutting down on meat and animal products more generally. As for the rest of us, we can’t keep putting it off. Not if we want to tackle climate change.

Campaigners have of course been trying to persuade the public to eat less meat for ages. It’s more than four decades since Peter Singer’s consciousness-awakening book Animal Liberation was published. The Vegetarian Society has been going four times as long. Over those years, there have been countless exposés of cruelties in factory farms and of the damage that farming can do to the local environment, and doctors increasingly warn of the risks of eating too much meat.

But if the aim of all this was to reduce meat consumption, those efforts have failed. Vegetarianism might now feel like a part of mainstream culture, rather than the eccentricity that it once was, but there’s little sign that more people are quitting meat. Nor is there evidence that many people are reducing the amount they eat. In the US, meat consumption per person fell during the Great Recession but it is now rising again. It looks like economics was the driving force, not ethics. In the EU, meat consumption is steadily increasing.

The world will soon suffer the effects of extreme climate change if we don’t deal with this. Meat and dairy production is responsible for around a seventh of all of man-made greenhouse gas emissions, and that proportion is set to grow remorselessly. In the effort to avoid dangerous warming, the world is beginning to eliminate the worst sources of emissions, like coal power stations. But, with meat consumption set to double by 2050, just the emissions from raising animals for food may be enough to tip global warming beyond safe limits—even if everything else was cleaned up.

“In the US, meat consumption per person fell during the Great Recession—but it is now rising again”

There are solutions to this. The choice of meat matters and tastes are heading in a cleaner direction. In richer countries, chicken has taken the place of beef as the most popular meat, which has cut emissions—beef warms the planet about four times as much as chicken. But the switch has been so slow that population growth means the total amount of beef eaten is barely falling. And, though cleaner than beef, chicken is still several times more polluting than vegetarian alternatives.

Technology might help. Meat substitutes like the vegan Impossible Burger, which release a fraction of the emissions of beef, could make a switch more palatable. As a recent convert to being mostly vegetarian I’ve found that even the limited range of meat substitutes now available help me cut down on meat, as vaping does for smokers (though I’m still far from convinced by cheese substitutes, which is why, like Corbyn, I would find veganism too hard).

But technology won’t fix the problem on its own. Even if vegan alternatives keep getting better, most people will need more motivation to switch. As long as the substitutes are neither tastier nor cheaper, why stop eating cheeseburgers?

This could be one of the hardest problems the world will have to face as it tries to avert extreme climate change. When it comes to other ways of cutting emissions—like switching from coal to solar power, or ditching inefficient fridges—we are making progress. But it will be much harder to persuade nearly everyone to cut down on something they enjoy for the sake of the climate, when arguments about health, animal welfare and the local environment have failed.

The interest in Corbyn’s recent comment demonstrates how far public debate still has to come. If this is one of the world’s hardest problems, it’s also one of the most ignored—few people outside the green movement are prepared to admit that consuming less meat and dairy is necessary. All Corbyn did was say he’s considering changing his own diet. Just imagine the outrage if he’d suggested that others should do the same.

But we can’t put off confronting the consequence of our diets for much longer. Cutting emissions is only getting harder, as targets get tighter and easier measures are ticked off. Soon we will have to look at our plates and admit it won’t be possible to prevent extreme climate change as long as we keep filling them with cheese and meat.

The Climate Majority: Apathy and Action in an Age of Nationalism by Leo Barasi is published by New Internationalist on 21st September

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