Scorched earth an insecure place

The measured prose and bland title of the latest UN report on climate change belie the gravity and significance of its key message: that the earth will soon be a much hotter, drier and stormier place, and there is little doubt our way of life is the cause. This is not a naturally occurring cycle, as a dwindling band of sceptics maintains.

Of particular note is the growing belief among the world's top climate scientists that it will be virtually impossible to keep the rate of temperature increase below 2C, which is widely accepted as the threshold above which managing the risks becomes progressively more difficult and the consequences more dangerous. It is necessary to bear in mind the unprecedented rate at which the planet is heating up.

We have no experience of dealing with such rapid warming. Natural climate shifts of this magnitude typically occur over tens of millennia, not a few centuries. It is critical for governments, business and the public to understand this important difference. There is very little time to make the substantial adjustments necessary to bring down the rate of warming this century so that we can achieve climate equilibrium in the next.

Now that science has given us a better, though still imperfect, appreciation of the challenge ahead, it is time to focus on the consequences we can reasonably predict. The Stern review, published last October, shed much needed light on the economic dimension of climate change, including the cost of fixing the problem and how we might best manage the transition to a low-carbon global economy.

But there has been precious little thought about the foreign policy and security implications of climate change, which are equally profound and inseparable from the economic and environmental aspects.

Energy policy is illustrative. The domestic debate about the ramifications of global warming for Australia's future energy requirements has been far too siloed and parochial. Future policy on nuclear power and the export and processing of uranium should not be determined by environmental and economic considerations alone. We also need to think about our relations with other countries, our commitments to the Nuclear Non-Proliferation Treaty and the risk of proliferation.

The latter has been much exaggerated by opponents of nuclear power, but the point is we need to have a much wider debate about energy and climate change policy that includes, rather than ignores, foreign policy and national security.

There are other, more pressing reasons for taking a holistic approach. Climate change is fast emerging as the security issue of the 21st century, overshadowing terrorism and even the spread of weapons of mass destruction as the threat most likely to cause mega-death and contribute to state failure, forced population movements, food and water scarcity and the spread of infectious diseases.

The Intergovernmental Panel on Climate Change confirms and adds greater certainty to what climate scientists have long predicted: that extreme weather events are set to increase in frequency and intensity. Rising seas, caused by thermal expansion and melting ice, will inundate many low-lying coastal areas, threatening cities and productive agricultural land.

Some small Pacific islands will become uninhabitable but no country will be unaffected, as Hurricane Katrina demonstrated when it devastated New Orleans 18 months ago. Images of the US 82nd Airborne Division patrolling the deserted streets of the city seemed like surreal scenes from a B-grade Hollywood movie at the time, but they are a portent of the future.

Indeed, things could be a great deal worse if some of the more extreme climate forecasts come to pass, such as a further acceleration of glacial and icecap melt and temperature rises above 3C. Although the balance of probabilities suggests that the more manageable mid-range predictions of the IPCC will be borne out, the worst-case scenarios cannot be dismissed, given the lack of serious global action to date and the IPCC's reputation for conservative judgments.

Already, events on the ground are calling into question some of these judgments. While the IPCC forecasts that the north polar icecap is likely to melt by the end of this century, many leading scientists believe this will occur much earlier, perhaps as early as 2040 and certainly by 2060. As greenhouse gases trapped beneath the frozen tundra are released and deforestation and land clearing continue unabated, the resultant carbon imbalance will exacerbate the warming trend, perhaps more than the IPCC allows.