At what point will you consider that this danger is past(for the foreseeable future)?

Unfortunately I don’t have easy access behind the GRL paywall these days; I’d be interested in the comments of anyone who does on Lean and Rind’s methodology.

So through our global warming experiment we should discover what 130 times the current background levels will do to the planet as the century rolls along.

Kind regards
Tim

Thanks for trying to get us some audio, for the photo and your narrative on the ‘dramatic moment’ – gives those of us who couldnt be there a sense of what went on.

Fang – Mike Seyfang

I did attend the session and did not enjoy some of the arguments and the way they were presented.

Ian Plimer’s style is to use a series of bits of arguments to disprove the anthropogenic climate change as a hypothesis, and then to climate change must always be due to something else.

There were silly suggestions such as asserting that climate models cannot predict past volcanic events and past El Nino cycles etc., that actually occurred. Barry answered this by suggesting that the models predict the frequency and nature of such cycles, but not an exact point in time as to when these would occur. In the same way, I don’t know if February 4th next year will be raining or sunny, but I can be prety sure that we are likely to have more hotter sunny days in February than we experience in July.

There were many other partial facts which seemed to be presented as factual global events and I have read many line by line responses to such arguments.

The question that Ian Plimer did not answer and will not answer as far as I can tell is, ‘at what point?’ will he consider that there is enough evidence to support a global risk management response to the problem of climate change.

We are all in violent agreement that climate changes, has always changed and will always change. The IPCC suggests that the human cause can add onto and trigger stepped changes that may result in 2 degrees warming to over six degrees by the end of the century and with such change our home won’t be a pretty picture for human settlements and current ecosystems.

I can only assume that Ian Plimer would not change his view even if the planet is tripped into global warming of 3 degrees by 2050. The same arguments and the disregard for the work of many climate scientists can still prevail. I really do hope that Ian Plimer is right and the buffering features of the planet will soften the impact of positive feedback loops, but this is hope and not science. I am puzzled by Ian Plimer’s approach that human forcing cannot have an impact when he acknowledges that many other forces frequently change climate. For insight, my reading of his logic is that volcanoes release such large volumes of carbon dioxide that the human signature is trivial in comparison. Whilst I am sure that in geological time this is true, I would be keen to again see the context (and numbers) of human greenhouse emissions against volcanic emissions over the last 4 million years (Barry or someone?).

As a policy officer (not a climate scientist) my decisions will be based on the IPCC advice, and assessments of how humans are behaving in terms of their emissions. I am happy to adjust my role in managing risks as the science is updated.

So what does it take to motivate others to manage the risk? Would it be a current IPCC Assessment report?, 1 further degree of change?, 3 degrees change?, 6 degrees change with no new climate forcing agent identified?, 1-2 metres of sea level rise?

My kids are being placed in a planet that is a bit like an airplane to the future. Planes crash every so often but in this case, the Climate Scientists are advising that the plane is not airworthy. Just because planes have crashed in the past, it does not mean that safety is not important now.

Guess who gets front-page billing (although only #7 in the list)?