AT FIRST sight, Ross Garnaut's proposal that Australia should cut its greenhouse gas emissions by 10% from 2000 levels by 2020 looks soft. The scientists tell us the world needs to go on a war footing to avoid catastrophic climate change. Is this war? The European Union has pledged to cut its 2020 emissions to 20% below 1990 levels, and will go to 30% if others do the same. Last year's ministerial conference in Bali floated targets of 25% to 40% for developed countries. Whydon't we aim higher? Maybe it's because Professor Garnaut is an economist, and keenly aware of what things cost in the real world. Maybe it's because he knows that, even with all the new policies, Australia's emissions are still on track to increase 20% from 2000 to 2020. That means he is proposing that, in 10 years once emissions trading starts in 2010, we should use it to cut our emissions from 120% of 2000 levels to 90% of them. That is a big shift, mister. That is a serious policy change.