It would be unlikely for the chief scientific adviser to the British Government to be a crackpot, one whose opinions could be dismissed as frivolous? You would have thought so. And Professor Beddington wasn't alone in the general tenor of his views, was he? No. He was not. Two weeks ago, four CSIRO scientists — while stressing they did not speak for the CSIRO — appeared before the Senate inquiry into carbon emissions. Not only did they say the Australian response was inadequate, one of their number, Dr Michael Raupach, said: "Well, I think that the scientific community as a whole, including every climate scientist that I know in CSIRO, is of the view that first, climate change is a very serious problem, and second, that global strategies at the moment are inadequate." And so, says the voice from a future that has seen Professor Beddington's prediction come true, what did you do? The answer, for most of us, is pretty much nothing.

By now, some readers of this article are screaming: what if Professor Beddington and those like him are wrong? They will be citing scientists supporting their own view and I can't argue with their science any more than I can argue with Professor Beddington's. There'll always be an expert with another view. Does that mean I have no voice at all when (a) I do have a voice and (b) I am no less qualified than many of those already participating vigorously in the debate. What do I know? I know that 25 years ago, when I came to live in Victoria, it sold itself as the Garden State. Look at the garden state now. In December, I went to Lake Bolac in western Victoria, passing a relatively new sign on the edge of town saying "home of aquatic sports" and other relatively new signs telling you where to back your boat in — but there was no water in the lake. I hear voices saying that maybe the lake has been dry before. Maybe it has. But in the past three years, Lake Bolac has also had its highest and lowest temperatures ever recorded there, plus its first tornado, which left wheat silos lying about like crunched-up beer cans.

Driving around Victoria over the past decade, I have seen it getting drier and drier. Then, on February 7, we had the fires. I have had it put to me that the Victorian bushfires of 1851 were worse. Maybe, in some respects, they were, and there are all sorts of reasons for that. But, more saliently, when the bushfire of 1851 occurred, was the top half of Australia inundated with record flooding rains? Were there reports coming in from around the world of corresponding climate abnormalities? This month, we have again had the debate over asylum seekers. To date, it has seemed remarkably like the debate that swept the Howard government to a second term. But if Professor Beddington is correct, if countries such as India and China experience significant shortages of food and water, we could, within a decade, have a world in which hundreds of millions of people are on the move. Current political debate would also suggest that the idea of growth economics is still a political virtue. As a reality, it may already be in the past.

The potential issues now facing us are almost unimaginable in their range and complexity. The political problems are immense. If you accept that the burning of fossil fuels on a massive daily scale is the principal agent of climate change, you are then confronted with the fact that this practice is intertwined with an enormous range of contemporary human activities, ranging from industry to sport, from medicine to housing. That's a lot of people with an interest in the status quo and, in consequence, a lot of political inertia and obfuscation. British law is ultimately based on the notion of the reasonable man. I think a reasonable man would conclude from the data now appearing before him from around the globe that he has serious cause for concern about the environment. Most people, in my experience, now admit that something is "going on" with the weather. Asked if they think dramatic changes are on the way, they say: "Maybe, but not in my lifetime."

But what sort of an attitude is that? I have a granddaughter who will be 21 in 2030. What am I going to give her for her 21st? Only this, perhaps. Before I speak on the climate change, I will remind myself that this is not a media game, that there is a high seriousness to this debate now, that I am — we all are — answerable to the future.