There used to be a hardback book at home called The Coming War Between Russia and China by Harrison E Salisbury. I used to stare at the spine gloomily in the 1970s, my anxious little brow would furrow and I would worry how this armageddon would affect me when it happened, which it obviously would – otherwise why would a grown-up write such a massive book?

The book is long out of print and its gloomy prognosis never came to pass. But the conflict it projected is merely one of myriad disasters that James Lovelock, the first prophet of environmental destruction, is predicting for us over the next few decades. (He says that as the world gets hotter the Chinese will have to move north into Siberia and the Russians won’t like it – ergo that war.)

There is lots more in that vein. Lots. Indeed, his outlook for the human race is frankly so poor that it makes you wonder whether there’s any point at all in going on, because what he seems to be saying is that we are all doomed. Sorry.

In this month’s Rolling Stone magazine Lovelock, the man who came up with the Gaia theory – that Earth and the atmosphere is a living super-organism – reveals his view that by 2100 the world’s population will be as few as 500m, down from 6.6 billion today.

In other words, that by the end of this century about six billion people will die – after mass migrations and pandemics caused by global warming. By 2020, he believes, droughts and extreme weather will be the norm (not the scattered showers so dear to our forecasters), the Sahara will be moving into Europe, Berlin will be as hot as Baghdad, populations will live off man-made comestibles such as Quorn because there will be no land to grow food and, oh yes, London will be under water.

Before you rush to buy your G-Wiz electric car or order your low-voltage light bulbs in a fit of eco-panic, just hold on. Lovelock also thinks it’s too late to cut greenhouse gases and that ethical shopping is a scam. “Green is the colour of mould and corruption,” he says.

Is it? Should we really be listening to the views of one man just because they are eye-catchingly more dramatic than the consensus (of which more in a second)? I hope not. I think it’s irresponsible. If Lovelock is right, well then it is all over, hard cheese, but if he’s wrong then he is telling people that nothing can be done, just at the point when there’s still one last chance to prevent the doomsday scenario that he lays before us with something bordering on relish. And since he, at 88, isn’t going to be around for the denouement, he is rather free to say what he likes and hang the consequences.

As I write, the Intergovernmental Panel on Climate Change (IPCC) is meeting in Valencia and is about to release its critical fourth assessment report. This report will confirm the theory that Lovelock first posited in the late 1960s: that global warming is man-made and irreversible (the Saudis and the Americans didn’t like it, but let it pass). But crucially the IPCC – after four years’ work, the collection and analysis of 29,000 data sets and input from thousands of scientists (600 scientists write the report, but 4,000 are nominated peer reviewers) – is also set to conclude that there are still “options” and it’s not too late to save the planet.

Next up there’s a United Nations meeting in Bali in December where presumably – if world leaders felt it was worth doing something to save the planet rather than the far more important business of getting themselves reelected – there is so much that could be done.

For example, since as much as 25% of global CO2 emissions come from the destruction of tropical forests, countries such as Indonesia, Brazil and Congo could be paid not to cut them down. Almost half of all life on Earth exists in forest canopies, which also play a vital role in maintaining the world’s climate, so this is win-win in a big way.

World leaders could also pour money into technology to jack up the carbon absorptive capacity of the Southern Ocean, and they could encourage China to invest in carbon capture techniques if it does insist on opening a coal-fired power station every 20 days. They could commit to doing something that has long fallen off the environmental agenda – reducing global population growth. There’s still everything to play for.

I understand where Lovelock is coming from. He argues in his latest book, The Revenge of Gaia, that the Earth is heading towards the “tipping point” when it comes to warming and there may be no going back. But Lovelock is surely overplaying his hand by insisting that the end of the world as we know it is a virtual fait accompli when it’s not, according to the consensus. Not yet anyway.

It’s as if, aged 88, with his reputation as a scientist assured and his “new natural habitat” of 35 wooded acres in Devon, he can afford to remove hope from the bottom of Pandora’s box for our descendants, just when they need it most.

Who will be Christmas No 1 – the First Emperor or Tutankhamun? I haven’t seen the new Tut exhibition at the former Millennium Dome, but I did queue for what felt like the Cretaceous period to see the 1972 version at the British Museum and my money’s on Qin Shihuangdi.

One, the British Museum has housed the terracotta army on a false floor above the reading room, so you can acquaint yourself with the man who unified China while standing over the desk where Karl Marx wrote, which is a trip.

Two, the BM is just steps away from the coin shops of Bloomsbury rather than in – er, let me just Google the dome – oh, north Greenwich. Three, the BM is hushed, serene and awe-inspiring while the dome or 02 Arena whatever, with its multiplexes and pizza parlours, is as quiet as Gatwick during a half-term baggage handling strike. Four – and above all four – the Chinese win in Qin v Tut because the Egyptians ruined it all when they showed us the pharaoh’s face.

Until that point I had been as fascinated as anyone else by the 3,000-year-old boy king, with his kohl-rimmed eyes and serpent coiled on his forehead, but mainly because he wore a mask. It seemed plain to me that removing it would not only be sacrilegious but also silly. Whatever lay underneath couldn’t fail to be a let-down. And so it proved. As my eyes fell on the blackened visage of Freddie Mercury after he’d been in a bad house fire, the allure that had lasted for three millenniums vanished in an instant.

Meanwhile, the First Emperor still lies in his massive burial mound in Xi’an, protected by mountains and forests and his vast terracotta army. Clearly the First Emperor wasn’t expecting company because, according to one account, he ordered rivers and seas of mercury to course through his mausoleum. Not surprisingly the Chinese – who invented feng shui – aren’t keen to mess with these well laid arrangements.

The Chinese seem to understand the point about daylight and magic, and also the equation that once curiosity is satisfied, something much more precious is lost for ever.

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