Governments can unite a whole nation under threat of war because the evidence of the danger is so clear. There is nothing like an armed enemy to concentrate attention and stimulate strategies for protection and counter attack.

One of the reasons the debate about climate change is so divisive and spawns as many sceptics as converts is that the evidence for and against is so hard to pin down. The “enemy” is not clearly in sight.

Since the mid 20th century, temperatures in Australia have risen by 1 degree centigrade on average. Heat waves have increased in frequency and intensity, frosty mornings and very cold days have decreased in number.

Rainfall in the northwest of the continent has increased markedly in the past 50 years and declined over much of eastern Australia and the far southwest.

These are persuasive statistics yet they don’t quite overcome the objection that such has always been the case. Australia is a land of heatwaves and sparse rains, of marginal lands and fickle seasons. That’s always been the story and extremes either way come in cycles - or so the sceptical argument goes.

But perhaps the bigger picture is also the most worrying.

The melting of the Arctic ice is proceeding faster than ever before and much faster than scientific predictions. If carbon emissions stopped this very instant, it would be fifteen years before the full effect would be seen. So an Arctic ice melt-down is not the stuff of science fiction: it’s a real possibility.

Such an event would massively alter the interglacial balance - that is the balance that has prevailed on the planet over the past ten thousand years, the time during which civilisations evolved, agriculture was established, and so on. The time when the world as we know it took shape.

As scientists, meteorologists and conservationists are claiming with growing urgency, scepticism about this phenomenon has now become a luxury we can’t afford. In our own environment in the beautiful Clare Valley as much as anywhere else in the country, we need to be receptive to the strategies that will arrest climate change – before the world as we know it loses its shape.