The most frequent false claim about the data is that there has been no warming since 1998. For a long time I’ve wanted to demonstrate explicitly the cherry-picking behind this claim. Now here it is (taking advantage of some free plotting software I recently downloaded, and generating an animated gif at a free online site).
Here is a graph I’ve wanted for a long time. It shows how you can get the answer you want out of the global temperature data series. Just pick the right start and finish point and, presto, the temperature is rising, or falling, or flat.
It’s why denialists keep insisting that global warming stopped in 1998.
[This is a draft. Over the next week or so I will be revising, adding links and making other versions to send to any news outlet that might take them.]
Here is the climate news. The real climate news.
So far the world has warmed about 0.6°C. If currently advised reductions of greenhouse gas emissions were realised there would still be a 90% chance global warming will exceed two degrees Celsius (2°C). 2°C used to be regarded as the threshold of “dangerous” climate change, but new science has shifted that threshold to only 1°C. 2°C is now regarded as the threshold of “extremely dangerous” climate change. At that level, global warming effects would be widespread and severe.
However, somewhere between about 2°C and 4°C lurks a tipping point, beyond which global warming will run beyond human control, driven by natural feedback mechanisms that drive temperatures higher, perhaps to 6°C or 8°C, no-one knows. 4°C would already be “incompatible with an organised global community”. Higher temperatures could result in the extinction half or more of the world’s species and much of the human population.
There’s not much more to say, really, about how we’re dealing with global warming:
“We’re running an epic experiment on global biophysical systems with only the faintest clue what we’re even doing, much less how to manage it. We know things could go rapidly, irreversibly, horribly wrong, but we’re not sure how likely that is, or when it might happen. So we just blunder ahead at top speed. Because coal is cheap.”
[Published on The Drum 20 May]
Recently climate sceptics Anthony Cox and David Stockwell published an opinion piece on the ABC’s The Drum claiming climate scientist James Hansen had “admitted” climate models have been wrong, and that human-caused global warming was therefore in doubt. The article contains basic misrepresentations of Hansen and of the substance and implications of a draft paper by Hansen.
The Hansen paper does not weaken the case that humans are the main cause of global warming. On the contrary, it suggests we have unwittingly and temporarily shielded ourselves from the full effects of our activities.
[I recently spoke to a teachers’ group about the state of the evidence on global warming. Having updated myself, and seen various reports of complacency, confusion or plain arrogant stupidity, I have written a summary here.]
As delegates argue in a Cancun resort on your behalf about who will reduce their greenhouse gas emissions first, what’s your own feeling about global warming? With record rain and floods all over the southeast and a big freeze in Europe, it may seem that global warming has taken a holiday.
[Published by On Line Opinion, 24 August.]
As the national election campaign approaches its climax, with global warming all but ignored by the major parties, the Australian Academy of Sciences has issued a report summarising the current state of climate change science. Its conclusions are clear and concerning. Global warming continues to occur, and the evidence is now strong that human emissions of greenhouse gases are the main cause. The evidence supporting supporting climate sceptics is melting like the Arctic snow.
[21 April: a version of this has been posted at On Line Opinion.]
The committee charged with examining the quality of the climate science conducted at the University of East Anglia has found “absolutely no evidence of any impropriety whatsoever”, according to its Chairperson, Lord Oxburgh.
Accusations of fraud or scientific misconduct have been widespread since emails were illegally hacked from the University of East Anglia’s Climate Research Unit last year. Oxburgh continued “whatever was said in the emails, the basic science seems to have been done fairly and properly”. The committee considered that if there had been misconducted they would very likely have found it.