When a film about climate change featuring Al Gore, An Inconvenient Truth, was shown in Parliament House in Canberra on Monday night, even the enviro-sceptics and climate change flat-earthers were shocked. Climate change requires determined government action and a change in the way we live that goes well beyond the next electoral cycle.

The film examines some of the effects of climate change: extreme weather - droughts, floods, cyclones; the potential displacement of millions of environmental refugees as water levels rise; extinction of plant and animal species. It shows that last year was the hottest year on record, and the 10 hottest years have been in the past 14. Category 4 and 5 cyclones and hurricanes have doubled in the past 30 years.

Gore's film focuses mostly on US science, but the Australian context is just as scary. By 2030, the CSIRO says, Sydney's water supply will drop by 25 per cent, as will rainfall in the Murray-Darling Basin. Domestic food supply and agricultural exports will be affected. NSW is experiencing its worst drought ever. Wetlands such as Kakadu face permanent change and warmer oceans threaten the coral that builds our Great Barrier Reef.

It's not just environmentalists who recognise climate change as a major threat. Businesses are ahead of the Government in understanding the need for urgent action to cut soaring greenhouse pollution. Business needs the investment certainty that comes from a long-term target to reduce emissions.

The report of the Australian Business Roundtable on Climate Change says Australia can deliver significant reductions at an affordable cost. Furthermore, the longer we delay acting, the more expensive it becomes for businesses and for the wider Australian economy. They argue for early action to minimise economic damage through a gradual adjustment, and to maximise opportunities to develop and export low-emission technologies to the likes of China.

Australia has more endangered animal and plant species than any other continent - numbering hundreds - with 54 animal species and 61 plant species already extinct. Climate change will speed their demise. The number of bird and animal species listed as extinct, endangered or vulnerable rose by 41 per cent in the 10 years to last year.

Mountain pygmy possums provide just one example. In winter these possums live in the relatively warm pocket of air created between the ground and the snow-covered gorse and heath of the Kosciuszko National Park. They are protected against cold that would otherwise be lethal. Because of global warming snow falls are declining. Instead of a blanket of snow the possums are getting only rain, which melts what little snow has fallen. Without the protective blanket of snow, the mountain pygmy possums are likely to be among our earliest casualties from global warming. It's probably too late for this species, but with determined action we may be able to save others.

The respected international biodiversity expert Professor Norman Myers has warned the world is facing the largest mass extinction in 65 million years. Myers told the National Press Club in March that Australia's conservation efforts would be brought to nought unless we tackled climate change. There was little point trying to protect individual species, he said, without tackling global warming.

The Environment Minister, Ian Campbell, recently blocked an electorally unpopular $220 million wind farm project in the marginal Victorian seat of McMillan. The wind farm would have reduced Australia's greenhouse emissions by 435,000 tonnes a year, the equivalent of taking 100,000 cars off the road. The reason given was that one endangered orange-bellied parrot might get killed every 1000 years.

We can't pick and choose the environmental science that suits our political purposes. Unarguably climate change is happening, although uncertainty exists about the pace of change - it could be that disaster is approaching faster than we thought. Australia needs a long-term target for cutting greenhouse gases and a serious plan for how to reach that target.

The Prime Minister should listen to business, the CSIRO, the Australian Greenhouse Office and the majority of Australians who agree that climate change is a major threat. He might also benefit from being strapped to a chair for 90 minutes and forced to watch Al Gore's film.

Tanya Plibersek is a federal Labor member of Parliament.

Copyright © 2006. The Sydney Morning Herald

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