If Caroline Lucas has always seemed an optimistic sort of politician, that outlook is being pushed to breaking point. Sitting through the budget last week was, says Lucas, “an unbelievable experience. It was like being in some weird parallel universe where there wasn’t a climate emergency, and we weren’t about to host the world’s nations at this big climate summit.” It should have been a moment when the chancellor, Rishi Sunak, “was turbocharging the funding for the net zero programme”, says the Green party MP, ahead of the Cop26 climate summit in Glasgow, which opened on Sunday. “It should have been the point where he reversed that unforgivable cut in aid, where we demonstrated some strong climate policies. Instead, the headlines were about cutting the cost of short-haul flights.” Her voice rises. “It’s almost as if he was thinking: ‘What can I do to send the worst signal ahead of this Cop?’ If I were Alok Sharma [the president of Cop26 and Conservative MP], I would be extremely angry because it feels as if he is being undermined by his own government.” She pauses, and gives a brittle laugh. “So objectively, it’s quite hard, looking at the evidence, to feel optimistic.” I had asked if Lucas felt positive about the summit, and she had given a long list of reasons why she didn’t – including the government’s slack approach to diplomacy, as host. She says Covid-19 has made it harder, but our efforts to get countries such as China on board still pale compared to what French politicians were doing ahead of the 2015 Paris conference. “We know that if you add up all of the different so-called nationally determined contributions – the individual countries’ assessment of how much they are going to cut their emissions by – that ought to be a minimum 45% cut by 2030. And if you add up what we’ve got so far, it’s leading to a 16% increase. “So on the emissions reductions, we’re not there. On the finance, we’re not there. Since 2009, we’ve said we will be providing $100bn to the developing countries by 2020, and we’ve still not got to that amount either.” On top of that, Lucas says, “The richer countries have not provided the [Covid] vaccines that they promised to poorer countries. I think the developing countries are going to arrive in Glasgow feeling incredibly let down.” Still, she says, smiling as she speaks via Zoom from her home in Brighton, there are glimmers of hope. “The public pressure and movements are gathering like never before. We know the public want leadership on this – they want the government to go further, they are absolutely up for bolder and more ambitious action. I take some hope from that, but on the evidence right now, I think it’s not too late, but it’s going to be tough.” Lucas has called Cop26 “our last best chance”. What will happen if it’s not successful? “This is the moment where it feels like public pressure and awareness is at its greatest. We know that this decade is going to be just about the most consequential in human history if we are serious about the existential threat that the climate crisis poses to humanity. But I’m also aware that if we don’t get a good result, it doesn’t mean we should all pack up, go home and give up. Every single fraction of a degree makes a difference in terms of climate impact, every single tonne of carbon emitted makes a difference. So we still have to keep fighting for the next best moment.” Lucas also knows we are running out of “moments”. Her biggest fear is, “That we don’t act fast enough. That we exceed 1.5 degrees, that we get towards two degrees of warming and more of the extreme events that scientists have been warning are linked to the climate emergency really accelerate.” One of her favourite films is Franny Armstrong’s docudrama The Age of Stupid, set in 2055 – with its cities under floods or on fire, it looks more familiar this year than it did when it came out in 2009 – and she says a line from it still makes the hairs stand up on the back of her neck: “‘Why is it, knowing what we knew then, we didn’t act when there was still time?’ And frankly that is the question I go to bed thinking about, and wake up thinking about.” Lucas was elected as the MP for Brighton Pavilion in 2010, and is still the country’s first and only Green MP. She grew up in Malvern, where her father ran a small business – her parents were “most definitely Conservatives” and politics wasn’t part of her childhood. “I came late to it,” she says. As a bookish child, she was most interested in poetry and novels; she went on to do a PhD in 16th-century literary romance. In the early 80s, at university in Exeter, Lucas got involved with the anti-nuclear movement and the Campaign for Nuclear Disarmament (CND). “That’s what got me into politics more broadly,” she says. Although she never stayed at Greenham Common, visiting the protest “was my kind of introduction to the broader political world”. When she worked in the CND bookshop in Exeter, Lucas read Jonathon Porritt’s book Seeing Green, “which put together concerns around the anti-nuclear movement with concerns around the women’s movement and poverty and environmental policies. For the first time in my life, I saw some of the connections. It was a sort of a lightbulb moment, coming across that book and realising there was actually a political party that linked to these different symptoms of a wider problem, which is basically an economic model that puts profit and growth above people and planet.” One of the problems environmental campaigners face, apart from terrifying us, is how to sell the big changes we all – or at least those with affluent lifestyles – need to make. This is one of Lucas’s strengths, I think, because she is both clever and practical, and always seems pretty cheerful despite her dire warnings. On rampant consumerism, she says: “People are still going to need – and want – to consume things but there’s a lot of evidence to suggest that people get very frustrated, for example, when products have built-in obsolescence. A very popular policy that comes up again and again is a proper right to repair.” It would be great to have repair cafes everywhere, she says, where you can get your broken toaster mended “while you’re having a coffee, chatting with friends”. Not upgrading your phone every other year, she says, “is not seriously going to undermine people’s quality of life, but will give us a better chance of a life that’s liveable for everybody into the future”. There are always ways to design fair policies “that people buy into”, she says. Take flying, for example. “The citizens’ assemblies came out really strongly for a frequent flyer levy. That means if you were to take one flight a year, it will be much the same price as it is now. But as soon as you start taking the second, third, fourth, fifth, the price ratchets up steeply – that reflects the fact that 70% of flights are taken by just 15% of the population. It’s a small number, relatively speaking, taking a hell of a lot of flights that is driving the biggest rise in emissions.” What is frustrating, she says, is how so many of the policies that would also “get us off our current collision course with catastrophe” wouldn’t be about giving things up, but about improving life. “What is not to like about the vast majority of this agenda? Yet still we have governments who aren’t moving in the right direction.” The recently announced heat and buildings strategy – the one that said we should all have heat pumps – made Lucas furious, she says. Not only were the subsidies insufficient, but: “They put almost nothing into home insulation. It’s utterly inefficient and wasteful, and doesn’t work. If we had a comprehensive street-by-street, local authority-led home insulation programme, that would get people’s fuel bills down, improve people’s health, get climate emissions down, create millions of jobs all around the country. There are so many win-wins.” It was the same with other green initiatives. “It feels like you cannot underestimate this government’s ability to balls up good ideas,” says Lucas. About Boris Johnson, she is scathing. “He’s an absolute disaster as a prime minister. He doesn’t do what is right, he does what he thinks is popular.” On the Covid-19 crisis, “It has been so apparent that he waits until the last moment to act. He is utterly indecisive, doesn’t want to be unpopular and doesn’t want to take leadership. And, as a result, Britain has had one of the worst total death rates in the western world.” It also makes Johnson, Lucas believes, “uniquely ill-equipped to deal with a crisis like climate change, where you need public trust. At a time of crisis, whether that’s Covid or climate, you need leaders who have integrity, consistency and courage. And those are three words I would not associate with Boris Johnson.” As for the conference speech made by the Labour leader, Keir Starmer, “You had to wait over an hour to get anything on climate and it felt like it was one issue among many that needed to be addressed. It wasn’t the context within which all of those other announcements and decisions were being situated.” The government’s messaging is all over the place, says Lucas. In the summer, the Cop26 spokesperson, Allegra Stratton, was mocked for saying people should take small steps to combat climate change (she acknowledged it was not the whole answer) such as not rinsing dishes before putting them in the dishwasher. Lucas laughs, incredulous. “It insulted people’s intelligence – people know that the actions we need have to be commensurate to the scale of the crisis. You cannot say that this is the greatest threat to humanity, and then [advise] not rinsing dishes before you put them in the dishwasher. It’s the inconsistency that is so debilitating.” When Lucas boards the train to Glasgow this week, she says it will cost her four times more than if she were to take a cheap flight. “Lots of people aren’t in the privileged position I’m in to be able to say, ‘OK, in spite of that, I’ll go for that option.’ So let’s make it easier for people to do the right thing.” Does she think there will be a Green government in her lifetime? She smiles. “Yes, I do. Because if there isn’t, then unless there’s a Damascene conversion of the other parties, the future is looking pretty grim. I’m not saying that the Green party is the only party that has the answers, but we’ve been asking the right questions for a hell of a lot longer.” The party is hampered by the voting system: “Clearly, a change in the voting system is what is necessary before Greens can take the position I would say we should rightfully have, if you look at the level of support for the party.” But it’s also a party with divisions over issues such as gender, as well as its frequent leadership changes – Lucas, who was leader between 2008 and 2012, is still probably its only recognisable face – and complicated internal democracy. It had record local election results this year, but the Green party still looks far from a meaningful power. What does she think of Insulate Britain’s tactics? Last week, the protest group, which is campaigning to insulate all British homes by 2030, blocked roads on to the M25. “I think the tactics have become the story, so actually, we spend much less time talking about the need to insulate Britain and more time about whether or not it’s legitimate to take the actions they are doing,” says Lucas. “Although I’m absolutely a supporter of peaceful direct action, and have been arrested and acquitted myself for doing the same thing [in 2013 during a protest against fracking], I would feel more comfortable protesting on the issue of insulation outside the Treasury where they’ve got the money to be putting into those programmes, rather than on the M25 where motorists don’t have a lot of say over what policies get rolled out.” One of the biggest lessons from her decades of environmental activism, she says, “is that change can sometimes happen very suddenly and in unpredictable ways”. Sometimes, change is almost overnight. One recent example was the government’s U-turn over sewage spills last week, placing a legal duty on water companies to reduce sewage discharges into rivers and the sea from storm overflows. “We were told it was absolutely impossible to change, that it will cost far too much and, in any case, the government’s policy was just fine. Then, within a matter of days, that changed. The thing that keeps you going is the idea that things can happen fast and sometimes you don’t know what will bring about that breakthrough.” Change, says Lucas, doesn’t have to be slow. Which is just as well.