’m tramping through damp, long grass in the wake of two poodles,” Chris Packham tells me, over the phone, at nine in the morning, from his home near Southampton. “One of the joys of the UK is this rich, verdant colour at this time of year, so green that it’s almost blinding.” The naturalist’s voice, compelling and contemplative, draws you in and slows you down, to the point where you are concentrating hard enough to see what he describes, even when you can’t. Generally, of course, you can see it: Springwatch has been back on screens, packed with the images – baby birds with their gaping maws, treecreepers blinking – we have always cherished and lately come to rely on. Packham, 59, has such a natural, contagious sincerity in his enthusiasm that he should be in the “national treasure” class, one of those rare figures who unites the country and is immune from politics. But he determinedly is not – he won’t, today, talk about grouse, hen harriers or any of those bird-cruelty issues that have brought him death threats of the most lurid kind (dead birds hung up by his gatepost, Twitter abuse too awful to detail). The BBC, I am given to understand, would prefer him not to speak on these topics. But in January he fell foul of the neutrality police in another way: while promoting his documentary about the global population, he said that, for the sake of the planet, people should consider having fewer children (he has no biological children). Packham admits the idea is controversial, but “I approach things as a pragmatic biologist”, he says, calmly. “There’s not a racist cell in my body; I don’t think of humans as being different.” That was not my question, although he has been accused – nefariously, he says – of singling out countries such as Nigeria, and therefore pointing the finger at sub-Saharan Africa, when “the real problem is what you and I are consuming”. “Ultimately, we are all the same species, in the same place, at the same time, with the same problem, and if we don’t start thinking collectively to sort it out, then we won’t do it,” he says. “A global conversation about how many people the planet can sustain is something that has to happen.” I happen to disagree – if you look at the recent work of the social geographer Danny Dorling, it shows that birth rates are already in decline worldwide; we are entering a natural slowdown. What we have not managed to slow down is rich people’s consumption. But, in a way, this makes me admire Packham all the more: there is enough to contest in these choppy waters that he could avoid them altogether and still hold his head high as a passionate defender of the natural world. He does not play it safe, nor does he skirt the largest, most uncomfortable implications of his analysis. He worries constantly – about the IPCC’s warning that we have 10 years to solve the climate crisis, about the strongman politics dominating the world stage, about the loss of biodiversity and the long-term impact that will have on harvests – but he does not sound worried. He sounds like a man telling you that your boiler is broken, but he knows how to fix it. So, we don’t need only to have fewer children; we also need to stop eating meat. “The reason why Jair Bolsonaro [the president of Brazil] and his henchmen are ravishing the Amazon is that they want it for agricultural land. They want to grow soy there, and beef, and that’s because people eat it. If meat consumption were cut, we could sustain more people.” We need better leaders, given that we are living under “undoubtedly the worst portfolio of politicians that we could possibly have imaged in our lifetime”, and we need to “shape a new world” after the pandemic, with the environment at the centre of our decision-making. On reflection, we all know how to fix this boiler, just as we all enjoy the sight of a ladybird, but it is soothing and exciting to hear it described. Packham always says of his early life, growing up in Hampshire, that he was a bit difficult, emotionally adrift, until he took a baby kestrel from its nest when he was 14 and fell violently in love with it. This led to a zoology degree, at the University of Southampton. He got into TV not via presenting, but in production, for the BBC’s 1984 series The Living Planet. His career as a presenter started with The Really Wild Show, in 1986, when he electrified the nature scene with his Gary Rhodes hair and his apparently effortless fluency. He has an endearing Dr Dolittle quality; the defining images of his career capture him cuddling an animal or bird that does not like to be cuddled. Here he is with an owl, now with a badger. He is much more evangelist than showman. “I probably got as much joy out of other people reconnecting with nature as I have got from reconnecting with nature myself,” he says of the lockdown period. “It’s been an absolute joy to see people posting pictures with ladybirds on their fingers and frogs in their ponds and birds singing in their gardens, but they will now have to join our ranks and remember what they took from that, because we do have to fight for it.” As the pandemic confined us all to our homes, he and his 25-year-old stepdaughter, Megan McCubbin, launched The Self-Isolating Bird Club: half an hour a day of guerrilla twitching, broadcast on Facebook every morning. “People seemed to like it,” he says (7.8 million of them tuned in). He and McCubbin have since taken their double act to Springwatch. “The producers of Springwatch liked our on-screen rapport. I call it bickering, they call it on-screen rapport.” He is keen to stress that McCubbin is a good, sound zoologist in her own right: “She knows her stuff, she likes science and understanding things. She loves finding out things that I don’t know and she does that very easily.” You would struggle to say who is the straight man of the double act – they are both incredibly, winningly geeky. McCubbin is the daughter of Packham’s ex-partner, Jo McCubbin. They split up years ago, but Packham remained a large and influential part of her life – she came to zoology partly thanks to time she spent at the Isle of Wight zoo run by Packham’s partner, Charlotte Corney. He describes these relationships as “a relatively confused – but not too unusual, these days – family setup.” They all get on very well. “Charlotte goes to Jo’s parties; I don’t. I’m not a party sort of person.” (I am reminded of the joke about the doctor, the lawyer and the mathematician who are each asked whether it is better to have a wife or a mistress. The doctor says it is better for your health to be married. The lawyer says it is better for your finances to be unmarried. The mathematician says: “It is better to have a wife and a mistress – then they can chat and you can go off and do maths.”) He is relatively equanimous about the restrictions of the pandemic, as you might imagine of a person who does not like parties. But he is deadly serious about Covid-19. “Speaking entirely biologically, what the whole, horribly harsh, tragic lesson of the virus has taught us is that we are part of nature; we’re not there to hold dominion over it, we’re not above it. “We’ve always been exposed to pathogens – everything from smallpox to bubonic plague. We’ve beaten them through our advances in science and I’m not regretting that. But we are an organism, living on a planet, and the way we were living was unsustainable. We were overcrowded, we were eating animals that we’d shipped alive from one part of the world to another, and we’re paying a terrible price for it.” This is not a million miles away from the putative Extinction Rebellion (XR) stickers, disavowed by the group as fake, that read “Corona is the cure, humans are the virus”. But he reiterates that he is not against medical advances; he is very much in favour of people living long and healthy lives. Nevertheless, he does not situate the plight of mankind at the centre of his thinking; we are no more than one part of an infinitely precious ecosystem – and we are the part causing the problems. This is the kernel of his radicalism – and no broadcaster’s duty of impartiality will make him disavow it, nor his support for XR and similar movements. “That’s the most positive thing that we’ve seen – Extinction Rebellion, Fridays for Future. All those young people have taken to the streets, in an informed way and in a peaceful way. That’s been absolutely heartening. That gives me a sense of hope. “And again, in the last week, we’ve seen all of these demonstrations because of continued racism. Some of them have been violent. I never support violence, but a lot of people are very, very angry. When people reach that tipping point, they no longer sit in bars; they take to the streets and demand their rights. We need to be demanding a right to a healthy environment and I think we’ve started to do that.” (I spoke to Packham before the Bristol protest at which the statue of Edward Colston was torn down, so this should not be taken as a comment on that, but my impression is that his heart is with the angry protesters, rather than those bemoaning the civil unrest.) In his sentiment and his delivery – quietly passionate, unabashed by what is and is not considered acceptable – Packham is very like Greta Thunberg, who often says that she thinks her Asperger’s is part of what makes her the activist she is. She is not affected by convention or “the Overton window” (the range of policies deemed politically acceptable by the mainstream), but rather tells the truth as she sees it. Packham was diagnosed with Asperger’s in 2005 and has spoken openly about it since, although he does not describe it in terms of upsides. “I struggled terribly when I was younger. Not as a young child, but later, when I was an adolescent and going in to my 20s. And my hope in speaking about it openly was that young people wouldn’t suffer in the same way. Because if they had a better understanding, and the people around them had a better understanding, life would be a lot easier. And it’s been quite heart-rending; more people come up to me and talk about autism than do about natural history.” His job, though, is the same in both cases – to explain things, he says, in relatively simple ways. “I don’t mean that in a patronising way. I just mean speaking frankly and plainly.” The last time I interviewed Packham was five years ago. Back then, while powerfully exercised about animal cruelty, he was much more comfortable on the territory of other species, patiently explaining why he preferred birds to mammals (“I like feathers better than fur; I think eggs are neater than placental matter; I like things that fly rather than things that walk; and – this is a subjective thing – they’re a more beautiful organism”). But the geopolitical intensity of the world we are in now draws him back constantly to our species. “Let’s be honest: a lot of the governments that have mishandled the corona crisis are not going to survive it. I sincerely hope that there will be a huge peaceful shake-up and people will start moving in the right direction.” While he is careful about which governments he means, he is resolute about the right direction: away from fossil fuels and flying; away from careless consumption; away from considering the natural world a resource to exploit. We are good at solutions, but only under pressure. “One of the stats that I’m always drawn to is that, when Pearl Harbor was attacked, in 1941, 7 December, America was producing 4m cars a year. From that point until the end of the war, they only produced 141. That’s how powerful our ability to respond to problems is. They used that capacity to produce weapons.” I am surprised by the parable – it does not feel like humanity at its finest, that, when push comes to shove, we will throw everything we have at killing each other better. But he is not a sentimentalist – whether or not we are capable of great change, we are certainly capable of huge change – and that is what the world needs. I thought I detected a note of optimism, but he had returned to his house and was eating toast, so it may have been blood sugar. Springwatch is on BBC Two at 8pm every night until Friday; previous episodes from this season are available to stream on BBC iPlayer