We are often told that curtailing the freedom of business is coercive and undemocratic. But by what democratic principle should corporations and billionaires decide the fate of current and future generations? When a government releases them from regulation, it allows them to determine whether other people live or die. No one elected them to do so.

Even businesses with apparently strong credentials cannot be trusted with this extraordinary power. Take Marks & Spencer, famous for its “Plan A” environmental standards. Its goal, it says, is “to be a zero waste business across all that we do … we already send zero waste to landfill.” But a few days ago, it commissioned a wraparound ad in a limited number of Metro newspapers, in which a video screen was embedded promoting Christmas jumpers. The screen, battery, electronics and casing were designed for a single use.

For the first time ever, environmental policies are now central, almost everywhere. But they have scarcely been mentioned in most of the media coverage

It’s hard to think of a more profligate form of disposability. Marks & Spencer’s defence of this disgusting waste is that “the video screens can be recycled via electrical appliance collection points”. In other words, it’s up to the people who were handed the free paper to clear up the mess the company made (not that these complex materials can be fully recycled, anyway). I expect 99% of the screens went straight to landfill.

This week we discovered that greenhouse gases in the atmosphere have reached record levels, just as they need to be plummeting in order to avoid climate catastrophe. The first task of all governments is now to stop powerful interests, like M&S, from trashing the habitable planet.

This is the main criterion by which we should judge political parties. With this in mind, I read all the manifestos for the UK general election published so far. I was immediately struck by a remarkable gulf: between their emphasis, and the media’s emphasis in reporting them. For the first time ever, environmental policies are now central, almost everywhere. But they have scarcely been mentioned in most of the coverage, which is all about Brexit, spending pledges, immigration and the usual 20th-century themes. It’s a reminder that the most environmentally dangerous industry we face, largely controlled by billionaires, is the media.

This is not to say that the manifestos have got it right. The Brexit party’s content-free “contract” is a total joke. The Democratic Unionist party writes as if it has been leafing through the dictionary, trying to discover what “environmental” means. Some of the Tory party’s pledges are promising, but they’re so vague that it could wriggle out of most of them. Labour’s transformation is genuinely exciting, but is beset by some important contradictions. Plaid Cymru’s proposals are pretty good, but it has a blind spot on farming (it wants to maintain the EU’s disastrous common agricultural policy, apparently without modification). The Liberal Democrats, mostly, get it. But only the Greens have really grasped what it means to democratise our relationship with the living world.

Facebook Twitter Pinterest Former Green Party leader Caroline Lucas. Photograph: Jeff Overs/BBC/PA

One extraordinary feature of this election is that growth, for some parties, has become almost a dirty word. It is mentioned only twice in the Labour manifesto, both times with qualifications. The Lib Dems have made a crucial breakthrough, arguing that GDP should no longer be a government’s central objective; it should focus instead on wellbeing. This is a policy the Greens have been urging for years. By contrast, for all its talk about a “green industrial revolution”, the Conservative party is still bloviating about “unleashing” businesses and igniting growth through such disastrous projects as the Oxford-Cambridge expressway. It really hasn’t thought this through.

Who should I vote for? A bite-size guide to the UK election manifestos Read more

Almost all the parties, even the DUP, now talk about green transitions and a circular economy, but with radically different levels of detail. Labour’s threat to delist any company that fails to tackle our environmental emergencies directly addresses the issue I raised at the beginning of this column. Its green new deal, sustainable investment board and green transformation fund are all crucial steps – though it is profoundly disappointing to see Labour fudge the 2030 target for a net-zero economy that was agreed at the party conference. There are some major contradictions, such as its conditional support for new airports, and its adoption of the National Farmers Union target for carbon-neutral food production by 2040. Net-zero in the rest of the economy means that farmland must be used as a massive carbon sink, so farming needs to achieve not zero but a big negative figure, and by 2030 not 2040.

Labour’s rural policies are generally weak, and there are gaps in its rail and roadand energy plans. If it forms a government – minority or majority – it should invite the Greens’ Caroline Lucas to be environment secretary, importing the deep engagement it lacks. While I disagree on a couple of minor issues with the Greens, their manifesto sets the standard against which the others can be judged.

The scope of the Lib Dems’ new thinking is one of the biggest surprises in this election. The new duty of environmental care it proposes for private and public bodies, its proposed zero-waste and nature acts, its suggestion of new taxes on frequent flyers, legal protection for public space and support for rewilding are all new and welcome. But there is still too much voluntarism: it urges but does not compel banks and corporations to reform their environmental standards.

We cannot rely on market forces and corporate goodwill to defend us from catastrophe. We should vote for parties – in this case Green or Labour – that allow us to make collective decisions about our common interests, leading to democratic intervention. No one has the right to choose whether or not to destroy our lives.

• George Monbiot is a Guardian columnist