Online Discussion with Paul Gilding

James. From what I understand of the data, nuclear doesn't achieve much CO2 reduction until realistically 15 years after you press the "go" button. 10 years to get approvals and build it (if you're lucky) and around 5 years to recover the embedded CO2 in the construction. Some say more, some say less, but around that. So given we've not pressed go, that's 20 years plus in Oz. So it doesn't work for CO2 reduction. They do it because they perceive as good wedge politics, mobilises their base etc.

Yes, some sort of carbon pricing is absolutely inevitable, but I would no longer say a trading scheme is inevitable. But tax or trading and during 2010, I would say yes.

Andrew. Good question and a difficult one. One the one hand, yes, carry on as we are because it DOES build momentum and support. On the other, we need breakthroughs which implies that is not enough. The reason we put the white roofs in there was would that help shift the thinking as well as be practically useful? As per my earlier link to Hansen, he argues we are so far off reality we have to overhaul our approach completely. Hard question but one worth discussing frequently!

Tiernan. Good point and an important one, particularly in light of the numbers we are now seeing with heat stress, disease spread and so on. I think the way we bring all issues to the forefront is by getting the people engaged in an area talking about their area, so farmers talking about ag, business leaders talking about business and in the case you raise, medical professionals talking about health impacts. The numbers for example on coal also show how we need a holistic approach - e.g. not just coal and CO2 but coal and total health and environmental impact. This allows a more reasoned conversation.

Oh yes, it's confusing all right! The short answer is that no one knows for sure on some of these questions (due to the risk of challenge to high court) but the politics will be the key determining factor. Bob Carr wrote an interesting piece on Monday's Oz where he argued the most likely result was a Labor/Green negotiated CPRS. I think it's very hard to call yet and will be heavily influenced by 1) copenhagen and 2) the response to Abbott.

This is a real danger area for Australia. On the one hand we celebrate, correctly, the great advantage we've had with cheap energy. The trouble is our cheap energy is about to become a competitive burden, or more particularly, having the highest CO2 emissions per capita in the OECD, is a cost we can't afford. This argues for greater, faster action as economic reform done suddenly is painful and disruptive, so the early pain is the cheapest form!

This is a tough one. If we knew what conditions we would face, transition would be easier. Because we don't, it's important to build resilience. That means diversity of income sources so communities can adapt to a changing climate. I do think on balance rural communities are in a good position to adapt, more so than urban ones. New forms of energy generation and soil carbon are perhaps the two most interesting new developments. Food will continue to be a global growth area, underpinning rural economic security though.

I think the implications of this week are primarily that we will come to accept that an ETS is a tool in climate policy, not a climate policy. The lack of an ETS will force the government to beef up its other actions, particularly around efficiency but also in the huge area you allude to, of the implications for agriculture