Source: BBC2: The Daily Politics
URL: N/A
Date: 27/09/2013
Event: XXXX
Credit: BBC2
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Jo Coburn: Good afternoon, welcome to the Daily Politics. It's almost certain that human activity is responsible for global warming, says an international panel of scientists, despite global temperatures barely rising for the past 15 years. But can an increasingly sceptical public be persuaded?
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Jo Coburn: Scientists on the Intergovernmental Panel on Climate Change have today published the first part of their Fifth Assessment Report, setting out the current state of scientific knowledge about climate change. The panel's fourth report, which came out in 2007, was undermined by incorrect projections about how quickly glaciers would melt and controversy over the apparent exclusion of scientists who challenged the mainstream consensus.
But the IPCC insists it has learned lessons. Scientists are now more confident than ever that climate change is happening and that people are largely to blame. They say there is a 95% chance that human activity is responsible for more than half the observed changes since the 1950s. The culprit is the emission of greenhouse gases - the concentration of carbon dioxide in the atmosphere is 40% higher than in the pre-industrial era.
The report says that global surface temperatures will increase by the end of this century - on almost all scenarios for the future rate of greenhouse gas emissions, the average temperature will rise by more than 1.5 degrees Centigrade relative to the period 1850 - 1900. And, if emissions continue at a high rate, that is likely to exceed 2 degrees. However, the expected range of temperature increase this century is lower than in the previous report. The IPCC now suggests it will be between 0.3 and 4.8 degrees. That compares with a range of 1.1 to 6.4 degrees in the Fourth Assessment. This shift follows an observed and unpredicted hiatus in atmospheric warming since the late 1990s. One explanation for the pause could be that more of this energy is being absorbed by the oceans.
And on sea-level rise, the IPCC is now more pessimistic than before. The report says they will go up by between 26 cm and 82 cm by the turn of the century, a higher range than previously thought.
Well, with us now is the Conservative peer Matt Ridley, and the Climate Change Minister Greg Barker also joins us - welcome to the programme. Matt Ridley first of all - scientists are more certain than ever about climate change. We have to act, to limit the effects.
Matt Ridley: Well, what this report is effectively saying is that both extremes were wrong - people who say it's definitely not happening are clearly wrong, but people who say that we're in for catastrophe are also completely wrong. Because what this has effectively done is lower the range of likely projections to about 1 to 2.5 degrees over this century, most of which will be beneficial. In other words, it's going to be 70 years before we see any harm from climate change, and meanwhile we're seeing quite a lot of harm from climate policies -
Jo Coburn: But -
Matt Ridley: - so, you know, the models have clearly got things wrong, over the last 20 or 30 years. They didn't predict this pause, they didn't predict the climate change would be as slow as it has. And they're got to be revisited.
Jo Coburn: Right, but you do accept that climate change is happening, and they are pretty certain humans are to blame.
Matt Ridley: Well, what they say is that more than half of the climate change since 1950 is man-made, and I think just about everybody I know among the sceptical side of the argument as well as on the alarmist side of the argument accepts that - I certainly accept that, have all along.
Jo Coburn: But, when you say that climate change policies are doing more harm, are you saying it's better to live with the consequences of climate change than to take policies now that will actually do something to mitigate them?