Like many Greens, I'm a huge fan of Jeremy Corbyn. I'm hoping that he wins the Labour Leadership election - and the latest polling suggests that he will.

At the same time, I'm a Green, and without one shred of doubt I'm going to stay a Green. For Corbyn - for all his many virtues - is no Green. For he does not have an ecologistic approach.

What the Green Party should do, in the face of the 'Corbyn surge', is very simple. It should stay Green. It should make clear how the case of the Green Party is as strong as ever, even in the face of a Labour Leader being elected who in certain important policy areas agrees with us.

What exactly does that mean, in practice? First and foremost, it means accepting planetary boundaries, limits to growth and that even 'green growth' is no escape from those limits.

For Corbyn, like his mentor Tony Benn, is at heart an old-fashioned productivist, an advocate of a fantasised kinder, gentler industrial-growthism. This commitment of his undermines completely his laundry-list of 'green' policies.

The irresponsibility of 'growthism'

It is utterly irresponsible at this point in history to stay in hock to the ideology of growthism - as Corbyn does. We need, bluntly, to denounce Labour's same-old same-old commitment - a commitment it of course shares with the Tories and the LibDems - to endless economic growth.

Growthism without end makes it impossible to hit our climate mitigation targets, impossible to preserve wilderness and habitats, impossible to maintain green belts.

If Corbyn were ever to be PM, he would face an intractable tension between his commitment to some greenery (on the one hand), and his targets for industrial production and house-building and endlessly more economic activity (on the other). Guess which one of these would give way, in the face of this conflict? Only the Green Party can be trusted to safeguard our common future.

Moreover, the chimera of 'growth' has become the left's way of not having to get serious about redistribution, about aiming for equality. This is the dirty secret of growthism: it's a substitute for egalitarianism.

Corbyn et al secretly hope that, with the pie getting bigger, everyone can have more without big corporates and the rich having to tighten their belts that much. The pie can't keep getting bigger, because the ingredients are running out. But there's enough for everyone already: provided we share it.

For a particularly stark example of how bad Corbyn is in this connection, consider this: Corbyn wants to bring back coal-mining in South Wales! It would be hard to come up with a worse example than this of a growthist mentality, an out-of-date 'extractivist' fixation with mining and miners - even if he does want to use 'clean coal' technology to burn it.

Corbyn is probably more prone than most in Labour to enter into this fateful embrace with yesterday's fuel, coal, a failure to come to terms with the post-growth future in which we will be on a course of 'energy descent' and will power ourselves with the energy of the future: clean, green, renewable energy.

Taking land seriously

Next, being Green means taking seriously not just labour (as a Corbyn Labour Party will, in pleasant contrast to 'New Labour') but land. Land is the complement to labour; it is the other one of Polanyi's 'fictitious commodities'.

Labour's fixation on industrialism means that it has a blind spot about the vast downsides of endlessly industrialising. Especially of industrialising the countryside. Corbyn is no different here. He and his followers don't seem to have much 'affinity' with land.

Taking seriously land means, for starters, that the Green Party needs to be calling for a complete change in the way we grow our food. Out with 'factory-farming' - intensive industrialised production - of animals, of course; but out too with intensive industrialised production of plants.

I don't mean talking to plants, Prince Charles style, nor plants' rights. I'm simply talking ecology. We are as a nation and as a species destroying our soil, on which we and future generations utterly depend. We need to turn this supertanker around.

We need to kick our addiction to fossil fuels and chemical-based fertilizers; we need to invest massively in permaculture, agroforestry, organic farming and above all in agroecology. We need to end the absurd subsidies for mega-farmers who are wrecking our countryside, and instead we need to farm appropriately for our soils.

This means growing vegetables in some places, rearing animals - humanely - in others, and rewilding in still others.

Good food and food security

We cannot as a nation feed ourselves. This is a scandal and a danger, a key source of unresilience in difficult times. We need as a nation to eat (on average) lower on the food chain, but we also need to enrich our soils rather than destroying them.

This is something an intelligent eco-friendly regime of mixed farming can accomplish, while our current industrial agriculture certainly cannot. We need to achieve food sovereignty.

Hyper-mechanised agriculture is not the future: smaller-scale farming using human labour more is. We need to get more people back onto the land. Starting, obviously, with those who yearn to have land of their own but who can't get it.

Land reform isn't an issue only for countries like Brazil: we need land reform here. It is a disgrace that 0.6% of people in Britain own 69% of the land - incredibly, we are, in fact, an even more land-unequal country than Brazil!

We need to become a nation not so much of shopkeepers, as Napoleon famously once said, but of efficient and ecological smallholders. Labour has no interest in or appetite for land reform. Greens need to place front and central that we mean it on land reform.

We need to rebuild a sense of land as a commons. And we need to rebuild commons themselves, and recognise and institutionalise 'new' commons such as the net, the seas and the air. The new common-sense should be 'commons-sense'.

An integral part of taking land seriously and taking seriously that it is a commons - and no longer fixating only on labour and capital - is Land-Value Tax (LVT) in place of other forms of property taxation.

LVT has long been utterly marginal in the Labour Party, but is a long-standing landmark policy for the Green Party. It ends a huge source of unjust speculative wealth gain. It is pivotal in the replacement of regressive Council Tax with a more progressive and intelligent fiscal system. It helps to disincentivise building on greenfield sites. And so much more.

This trio of policies - ending soil-mining industrial agriculture, initiating a massive redistributive programme of land reform, and introducing LVT - establishes the Green Party's claim to be serious about land, which urbanite Labour aren't and never will be. And it pulls the rug from under Labour's exclusive claim to be the anti-Tory Party, the Party of and for the little guy.

Corbyn's Labour is never going to get anywhere in rural England. The Green Party can, and offers a package of policies that will enable it to become the main opposition to the Tories in rural areas, and ultimately defeat them too.

Work, work, work?

Crucially, truly being Green means ending the love affair which Labour has always had - and that Corbyn shares - with rewarding work, and so perpetuating an overworked society obsessed with the seize of its wage packets and focussed on consumption, keeping up with the Joneses.

Instead, it is our goal to create the leisure society: not in the sense of idealising idleness, but of giving us the time in which to enjoy and create fulfilment in life beyond paid employment. We should start by asserting our desire for an ever-reducing working week. Rather than taking any gains in productivity as more wages, we should incentivise and normalise working less.

It's absurd to have some people unemployed while others are hospitalised from stress resulting from overwork. Let's share the work out, more equally. And let's be glad when there's less of it.

But this is only the start. The truly radical policy measure to boost the UK in the direction of the leisure society is the unconditional Citizens Income. Again, a hallmark, central Green policy which Labour has never shown any interest in.

Sharing the wealth; sharing (and reducing our collective impact on) land; sharing (and steadily reducing the need to) work: this is the future. This is the truly radical agenda - not Corbynite Labourism.

So the Greens do have a clear argument against Corbyn's Labour Party. And that's important as without it, we'll probably wither. I want the Green Party to succeed because I profoundly believe in the ecologistic philosophy it embodies. And without it, we lack an offer that's distinctive.

The future is Green

We Greens must outflank Corbyn's Labour - not in conventional left-right terms, but through changing the conversation, reframing the debate, and advocating a radical change in direction for our society.

That means living within limits; respecting land as the foundation of food, life, wealth and culture; recognising our commons in all their manifestations; valuing leisure time at least as much as work; and sharing our skills, talents and resources in our communities and wider society.

Because the future was never going to be red, let alone orange. If there is going to be a bright future at all, it will be green.

Through his success in Labour leadership contest, Corbyn looks like putting an end to the hopeless dream of those who wanted to turn the Green Party into a Mark III Labour Party of socialism plus caring about climate change. Because that's what Corbyn will be in a position to deliver in the Labour Party itself.

So Greens must wake up and remember that we are so much more than that, with our own distinctive history, values, policies and purpose.

Because of this, Jeremy Corbyn's likely election may prove the best thing that ever happened to the Green Party. It's up to us to make it so.

Rupert Read was Parliamentary candidate for Cambridge for the Green Party in the 2015 election, and remains Green Party national Transport Spokesperson. In his day job he's Reader in Philosophy in the School of Politics, Philosophy and Languages at the University of East Anglia, and Chair of Green House.