News | 6th Nov, 2010

Wrong to dismiss the dirt on Hazelwood

Saturday, 6 November 2010
David Karoly, The Age

One hundred years from now, when rising sea levels are forcing millions of people in low-lying regions of Bangladesh, the Pacific islands and the Nile delta from their homes, who will they blame?

For some, it will be fair to point the finger at wealthy carbon-guzzling nations such as Australia, and at particular coal-fired power stations such as Hazelwood, and say: ''You did this.''

It is the harsh reality the next generation is likely to face and that big coal companies, such as Hazelwood owner International Power, should be very concerned about.

We often hear that Australia emits only a small fraction of the world's greenhouse gases, and so what we do makes little difference. But when the impacts of climate change are so huge, even a small share of the responsibility is a heavy burden to bear.

We can't say we didn't know. It is now almost 20 years since the world's governments signed the UN Framework Convention on Climate Change, agreeing to reduce greenhouse gas emissions to prevent dangerous climate change. Since then, the science has grown much stronger, confirming that burning fossil fuels such as brown coal increases the concentration of greenhouse gases in our atmosphere, leading directly to a warming of the climate.

These are general global findings, but is it possible to join the dots between the emissions from a coal-fired power plant such as Hazelwood through to tangible climatic and human impacts in the future?

Carbon dioxide is the single largest factor contributing to human-induced climate change. Burning coal is the largest source of human-related emissions of carbon dioxide. And the worst part is that it takes a very long time, more than 1000 years, for the earth's system to return to normal after extra carbon dioxide has been added.

The fingerprints of extra carbon dioxide in the atmosphere have been found in the observed increase in average temperatures, and this rise in temperature has been shown to lead directly to sea level rise.

According to the UN Intergovernmental Panel on Climate Change's best estimate for all future greenhouse gas emission scenarios, global sea level is expected to rise by at least 40 centimetres by the end of the century as a result of human-induced global warming. Assuming no changes in the level of coastal protection, more than 100 million extra people will be subject to coastal flooding by 2100. Many experts say this is an underestimate and that the likely sea level rise by century's end will be more than 80 centimetres.

The Hazelwood power station began operating in 1971 and since then has emitted about 600 million tonnes of carbon dioxide. Without policy intervention, the power station is expected to operate until about 2031 and emit a further 320 million tonnes. Over its lifetime, the emissions from this one power station will be more than the cumulative emissions of many small nations of the world.

Global greenhouse gas emissions are expected to grow rapidly but, even so, emissions from Hazelwood will contribute 0.01 per cent of total global emissions from 1970 to 2100.

Given the direct link from emissions of greenhouse gases to climate change and sea level rise, the emissions from Hazelwood can be pinpointed as a partial contributor to future sea level rise.

Since the rise is conservatively expected to affect 100 million people by 2100, Hazelwood's 0.01 per cent contribution will cause the annual flooding of more than 10,000 people somewhere in the world.

Who will these people be? Whose homes are we flooding if we allow Hazelwood to keep operating? It's impossible to know, but we can be sure that many people will suffer as a result of our actions, or our failure to act, in the face of such strong scientific evidence.

Reducing the emissions from the Hazelwood power station would reduce the risk of future climate change and reduce the risk of future sea level rise by a small but important amount.

In the Victorian state election campaign, there is now serious debate about replacing Hazelwood in the next term of government. While it is not our only polluting power station, it is arguably the least efficient power station in Australia.

Replacing all of Hazelwood would be an important symbol to Australia and the world that we are prepared to take action to clean up our energy supply. But it would be more than a symbol. It would also reduce future climate change and reduce the numbers of people impacted by flooding resulting from sea level rise.

David Karoly is a professor in the school of earth sciences at Melbourne University. He was a lead author on the Fourth Assessment Report of the Intergovernmental Panel on Climate Change in 2007. This is an edited version of a speech he will make at the Replace Hazelwood Rally at the State Library at 1pm today.