Alan Titchmarsh: Climate scientists should stick to the facts and not use guesswork

We live on a volatile planet. The very term 'climate change' is tautological in that that is what climate does – change. It would be a great story indeed if there was no shift in the climate at all.

By Alan Titchmarsh Published: 9:30AM GMT 31 Jan 2010

But as anybody who's lived for more than 50 years knows, things seldom carry on happening at the same rate for very long.
If you look back, there have been times in the planet's distant past – long before any human intervention – during which it has been very warm indeed. But nowadays, if you say this kind of thing, you're immediately branded as a climate change denier, which I find frustrating, particularly when it comes from scientists, who should be prepared to put all the facts on the table.
There's probably no doubt that our activity on the planet, and our current population numbers, are exacerbating global warming. But this does not take into account the warming and cooling that has happened before. There's barely a mention of previous types of global warming. Whenever it is brought up, it's quickly knocked down with an "Oh yes, but it's never happened at this speed before." That phrase is used to suggest that if we carry on warming at the current rate, then such-and-such will happen in X years.
But the danger of conversations such as this is that scientists extrapolate more and more, rather than look at the facts. There's a danger when guesswork starts to take the place of science – which is how the confusion surrounding the melting of Himalayan glaciers came about.
Now, I'm no scientist and no expert on climate change; I'm just the man on the street – perhaps one with a slightly informed opinion from working with the environment for the past 45 years. But whenever scientists are badgered for pronouncements – about future changes in climate or even weather patterns – they employ a degree of clairvoyance.
I think that's dangerous as they're backed into a corner and forced to make pronouncements about which they cannot be 100 per cent certain. I've already heard predictions that this coming summer is going to be a wet one – presumably exactly as wet as last summer was a barbecue summer.
As the man on the street, I need a balanced view, an informed opinion, to help me to decide for myself. I'm not at all denying the fact that we shouldn't be much more careful about and cautious about our carbon emissions – all of that I'm entirely in accordance with – but I think they do themselves a disservice when they enter the realm of what you might call Old Moore's Almanack predictions. Scientists should have the integrity to refuse to make predictions that they cannot back up with accuracy.
Now, this is not a scientist talking, but a practical gardener. And I can tell you that the seasons have certainly shifted. When I was younger, they used to recommend sowing parsnips outdoors in February. Certainly in the past 20 to 30 years there has been no way that you could sow parsnips outdoors in February, because winters have been wetter rather than colder, and you don't sow seeds in cold, wet soil.
Our seasons seemed to have slid imperceptibly into one another, rather than there being a dramatic change. Autumn lasts longer than it used to, so I find it rather heartening that just suddenly out of the blue you get a proper winter. It's been nice that these past two years we've had proper winters.
I've been gardening on the box and on the radio since the mid 70s, so for 35 years, and every spring without fail I'll get a phone call from a newspaper saying that the daffodils are either terribly early or terribly late, and what's going to happen. And it happens every year. Daffodils have an enormous capacity for waiting.
It's the same with snowdrops this year. They sat quietly and waited until the snow went and now they're coming up – it's not going to affect them badly by coming up later than usual. In fact, they'll probably do better because they'll be flowering at a time when the weather's more conducive to pollination, meaning the bumblebees will feed better too.
Birds' migratory patterns are also in a constant state of flux. The lines where how far north migrating birds from the south come, and ditto how far south the northern ones come, are always on the move. The danger is that we read too much into this.
I've spent my working life being concerned for the environment, so I'm not saying it's all fine, changes don't matter. It's just that we need to be a bit less headless chicken about it and have a more considered opinion.
When people are constantly harangued about what they shouldn't be doing to improve the environment, that's wrong. They begin to feel powerless to make a difference and just switch off and they do nothing. Most people are aware of all the "don'ts" now – they know they should drive their car less, they know they should insulate their loft.
I'd far rather they got some joy out of what they did in a positive way and did something that can improve their environment for themselves – by planting a tree, starting an allotment, or just making use of parks and outdoor spaces. There's so much pleasure to be had in taking care of the environment, it's not just an onerous task.