Christine Milne (Tasmania, Australian Greens) Share this | Hansard source

I rise today to note the report of the House of Representatives Standing Committee on Climate Change, Water, Environment and the Arts, Managing our coastal zone in a changing climate: the time to act is now. I note that at last we have a government committee saying what the Greens have been saying, what the scientists have been saying and what the community has been saying for decades. But the conclusion cannot be drawn that action on the very real threat of climate change to Australia’s coastal communities is going to be addressed by the government’s targets.

This is the most important thing: if we proceed with the Carbon Pollution Reduction Scheme and a national reduction of emissions target of 5 to 25 per cent, we will lock in a high probability that we will see the worst case scenario in this report actually come to pass. That is the critical thing. There is a massive disconnect between what the science is saying and what the government is saying. It is irresponsible in the extreme for anyone to report that the CPRS or the national target will in any way mitigate climate change or avoid the worst case scenarios.

We are talking about the fact that we have in Australia 711,000 addresses within three kilometres of the coast. This is a very real risk to Australia’s coastal areas. We know that with sea level rise we will get thermal expansion of the oceans as a result of increased temperature and increased and rapid melt of the glaciers. At some point we will also run the risk of losing the West Antarctic ice sheet and the Greenland ice sheet. I would remind the Senate that the Greenland ice sheet is equivalent to seven metres of sea level rise and the West Antarctic ice sheet is the equivalent of six metres rise—13 metres in those two ice sheets. No-one is suggesting that they are going to be influencing sea level rise tomorrow by 13 metres; what we are saying is what the scientists are pointing out. I quote Dr John Church:

There is an important issue of thresholds. We are likely to cross a threshold leading to an ongoing disintegration of the Greenland icesheet—and remember that the Greenland icesheet contains the equivalent of seven metres of sea level rise. We could cross that threshold late this century.

This is the key point:

At a 550 ppm CO2 equivalent level there is approximately a 50 per cent risk of crossing that threshold. That is not to say that the Greenland icesheet will disappear as soon as we cross that threshold, but unless we substantially reduce levels below that value there will be an ongoing disintegration of the icesheet …

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and if we cross that threshold there will be major impacts over many centuries or perhaps even millennia.

At 550 parts per million we are running a 50 per cent risk of crossing the threshold and seeing the one-metre sea level rise that we are talking about, with the most conservative science in the IPCC’s fourth assessment report, and we are running a 50 per cent risk of crossing that threshold. At 550 parts per million, that is precisely what the Rudd government is talking about. When it goes to Copenhagen with its targets, it is talking about 550 parts per million or more, and the scientists tell us that we should be aiming for 350 parts per million.

Do not let anyone be under any illusion when we have a minister stand up in here, note the report from the House of Representatives and say, ‘That’s why five to 25 is what we need to do.’ No, it is not what we need to do. As we already know, the great fear for Copenhagen is that we will end up with Copenhagen agreeing to 550 parts per million or more, and that is going to be locking in that kind of sea level rise. What we will then see is a tremendous risk to Australia’s coastline. Let me talk about some of the impacts of global warming on the coastline. Starting with the Great Barrier Reef, scientists are now very afraid of reaching a tipping point on ocean acidification. The CRC in Hobart talks about 450 parts per million as being the tipping point for ocean acidification. If you lose those structures in the Great Barrier Reef that hold the corals together, the corals are going to disintegrate and weaken, and when they are hit by a cyclone you will get a lot of destruction of the reef.

Let us look around the Australian coastline. We have Brisbane, which is incredibly low and vulnerable. The report of the House of Representatives Standing Committee on Climate Change, Water, Environment and the Arts says that in Tasmania 20 per cent of the coastline is already vulnerable. That is the kind of response we see. Looking around the whole country, it is not just coastlines but also estuaries. We are going to see flooding in those estuarine areas all around Australia. We have this suggestion that the federal government is in some way taking leadership on issues related to climate change and sea level rise, but I want to come back to Professor Steffen, who said:

Mitigation, as vigorously and rapidly as we can, is the best insurance against the worst of the projected coastal impacts. Obviously this is a global task, but as a country with a very high percentage of population and infrastructure in the coastal zone, it should be a high priority for Australia that the international community achieves an effective mitigation strategy at Copenhagen.

The government is running up the white flag on Australia’s coastline and the 711,000 residences on that coastline. For every metre of sea level rise, you can talk about up to 100 metres of incursion in vulnerable coastal areas. Australians must take notice of the House of Representatives committee report but they must then come back and say to the Prime Minister and to Minister Wong, ‘You cannot look us in the eye and tell us that your targets are in any way going to mitigate this outcome.’