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The latest disaster film The Day After Tomorrow pursues the theme of disastrous climate change associated with political denial driven by economics and patronage. How realistic is this theme? DR DAVID BUTCHER The latest disaster film The Day After Tomorrow pursues the theme of disastrous climate change associated with political denial driven by economics and patronage. How realistic is this theme? Abrupt, non-linear climate change is now widely accepted by scientists, it has happened before and the causes are slowly unravelling. The film is a dramatisation of the science with time-lines short enough to meet the requirements of the plot rather than the facts. A slowing or even cessation of the Gulf Stream, the ocean current that makes the Northern parts of Europe and North America habitable for humans, is central to the film. Without the Gulf Stream, Britain, for instance might have a climate similar to Macquarie Island. The major currents of our oceans are called the Conveyor Belt. The surface of the Pacific Ocean is warmed, displaced by up-welling colder currents, then flows between the South East Asia mainland and the Island of New Guinea into the Indian Ocean where it continues to be warmed. This warm surface current flows around Southern Africa into the Atlantic, continuing to warm until it becomes the Gulf Stream of the North Atlantic where a combination of evaporation and heat loss increases the water’s density causing it to drop to the ocean floor. Flowing as a deep, cold current said to be 30 to 40 times the volume of the Amazon River, it passes back around Southern Africa, south of Australia and then back into the Pacific where as the cold upwelling it recommences the conveyor belt. Ice ages are triggered by whole range of events but one that lasted a few thousand years occurred about 14,000 years ago as the world was coming out of the Pleistocene. Large amounts of Northern Ice melted suddenly overlaying the Northern part of the Atlantic. Fresh water and salt water don’t mix very easily, so the fresh water, being less dense, overlaid the warm Gulf Stream, stopping the Conveyor Belt or at the very least slowing it down. Loss of the warm current flow allowed the Northern hemisphere to cool rapidly, producing a ‘mini Ice Age’. Could this happen again? With 40 per cent loss of the Artic ice cap, rapid melting of Greenland and the Tundra of North America, it is certainly possible. Sounds a bit of a tenuous argument! Maybe, but there are plenty of examples of abrupt non-linear changes, even here in Australia. A couple of editions ago, I wrote about the Southern Vortex and our growing knowledge about the anthropogenic effect upon its action. The climate of Southern Australia is certainly changing with noticeable reductions in rainfall over the last 40 years. Inflows to Perth’s water supply are accurately recorded and have been for around 100 years. In 1974, inflows fell by 50 per cent. Since then, the average inflow has remained at that level, indeed there has not been one year in the last 30 that has reached the pre-1974 average. Even worse, since 1995 it seems to have dropped again. Certainly there were some unfortunate land clearing decisions made in the 1960’s but these cannot explain such an abrupt and catastrophic drop. While The Day After Tomorrow will remain a highly dramatised disaster film, the under-pining climate change theme must be treated seriously. WWF and the insurance group IAG brought together eight of Australia’s leading scientists to look at the issues of climate change, propose solutions Australia could pursue and determine whether we could make a difference. The paper ‘Climate Change – Solutions for Australia’, see www.wwf.org.au, is an excellent introduction to the issues and proposes some straight forward solutions, not easy admittedly, but ones that can lower the risk and which need to be addressed and accepted immediately. 1. REDUCE Australia’s political leaders must work with business and the community to take immediate action to cut our greenhouse gas emissions by 60 per cent by 2050. 2. TRADE Establish market mechanisms to trade greenhouse gas emissions, providing the business sector with a powerful tool to meet reduction targets. 3. ACT Encourage all Australians to take responsibility for their own role in reducing greenhouse gas emissions by using energy more wisely. 4. ADAPT Put in place measures to minimise the impacts of climate change, from building improvements to deal with more intense storms, to investing in new agricultural industries which require less fresh water. 5. INNOVATE New business opportunities must be developed and implemented as the rest of the world moves to low carbon energy futures. 6. LEAD A leadership role must be taken to identify and implement solutions to reduce the impacts of human- induced climate change. As one of the wealthiest and best-educated nations in our region, we can share our innovations and technologies with nations of the Asia Pacific. There will be those that say that even if we do our best in Australia, we are too insignificant to have an effect on global issues and indeed global emissions. There are three answers I would give. Firstly, Australians are one of the highest emitters of greenhouse gas per head. We can set a clear example to the rest of the world. While a reduction of 50 per cent would have less than a 1 per cent effect upon global emissions the solutions we would develop and put in place to do so would be sought by other countries. Secondly, Australia has always punched well above its weight. We excel in international fora and are leaders in the formulation and implementation of good ideas. We are one of the world’s largest exporters of fossil fuels. There is, therefore, a responsibility on the Australian Government and suppliers to work with those industries we supply to, to improve their efficiency and develop technologies, such as geo-sequestration, that can remove the threat. Thirdly, the development of new solutions and technology including geo-sequestration, which captures CO2 produced from coal and pumps it deep into subterranean aquifers. This is already being carried out in the natural gas industry with good results. There are many questions to answer and models to be developed and Australia has a vested interest in the resulting solutions. But time is of the essence and economies in energy production from coal must be the immediate priority. The earth is over-heating and the risks of us losing the natural systems that we take for granted and the way of life we currently enjoy are very real. The lack of knowledge and the potential paradoxes are great threats. What of the current information which shows that the sun’s powers have been diminished slightly over that last 50 years and yet the earth is still over-heating? Would the current effects be worse if the sun was not in a dim cycle? What will happen if the sun cycle changes and it starts to heat up again? Twenty years ago, what I have just related would have been treated as science fiction, but today it is science fact that is surrounded by a desperate scramble to find the missing pieces of the puzzle. The very fact that the insurance industry is concerned should give us pause for thought. Australia can be part of solving this global threat that risks the future of all living things around the world, but we will need bold leadership not just from politicians, business leaders and scientists but from every one of us. |
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