13 June 2011

James Hansen 350 Aotearoa

James Hansen gave an interview to 350.org.Aotearoa. during his speaking tour of New Zealand.

What is science telling us about climate change?

Why is 350 parts per million important?

What can we do about climate change?

How much time do we have?

All answered in 7 minutes 25 seconds.

03 June 2011

If you missed James Hansen in NZ

Jim Hansen spoke to over crowded lecture theatres during his recent speaking tour of New Zealand. In Wellington, 600 people listened to him - 300 in person in one lecture theatre and another 300 listened via a video link. I saw him speak twice and it was very much a highlight.

However, the New Zealand government still does not get it and is encouraging offshore oil, gas and lignite extraction.

Hansen more or less gave this talk.

Maths of climate denial

Bob Beale is the former science editor of The Sydney Morning Herald. The other day, 1st June, he gave an excellent explanation of why supposedly small amounts of carbon dioxide really do make a difference to global warming. Its on the Australian National Times web page in post called You are just plain wrong about climate change, Mr Jones.

His target is Alan Jones, an outspoken radio talkback host in Sydney.
Jones has been arguing that the carbon dioxide content of the atmosphere is about 0.04 per cent. Of the emissions of carbon dioxide into the air, 97 per cent comes from natural sources. Therefore humans are responsible for only 3 per cent, and of that, only 1.5 per cent is from Australia.

So, 1.5 per cent times 3 per cent times 0.04 per cent - Australians are responsible for an incredibly tiny 0.000018 per cent of global carbon dioxide.

Beale writes "No, the whole premise of his argument is a crock." and "The silly sums are time-wasting distractions that hinder debate on a complex issue."

"For every 10 million molecules of air, a mere four are ozone, yet thankfully they repel about 97 per cent of the dangerous ultraviolet radiation from the sun."

"Roughly 99 per cent of the atmosphere is not greenhouse gas - the piddling little 1 per cent somehow traps enough heat to make the surface of earth more than 30 degrees warmer than it would otherwise be."

"...carbon dioxide is steadily building up in the atmosphere...Since the start of the industrial revolution the level has risen sharply from 280 parts per million to 390ppm - the highest it has been for a million years. That's not surprising when you consider that last century alone, fossil fuel burning and cement production emitted more than 1.1 trillion tonnes (that's a one followed by 12 zeros) of it.

Beale concludes "Jones and his fellow deniers are headed down the same road as the rest of us, speeding inexorably towards 500ppm - and by then we'll all be well over the limit." Very apt.