Matt Ridley's new article in the WSJ – a dose of pragmatism about revelations from the new IPCC report

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Climate Forecast: Muting the Alarm

Even while it exaggerates the amount of warming, the IPCC is becoming more cautious about its effects.

The United Nations’ Intergovernmental Panel on Climate Change will shortly publish the second part of its latest report, on the likely impact of climate change. Government representatives are meeting with scientists in Japan to sex up—sorry, rewrite—a summary of the scientists’ accounts of storms, droughts and diseases to come.

But the actual report, known as AR5-WGII, is less frightening than its predecessor seven years ago.

The 2007 report was riddled with errors about Himalayan glaciers, the Amazon rain forest, African agriculture, water shortages and other matters, all of which erred in the direction of alarm. This led to a critical appraisal of the report-writing process from a council of national science academies, some of whose recommendations were simply ignored.

Others, however, hit home. According to leaks, this time the full report is much more cautious and vague about worsening cyclones, changes in rainfall, climate-change refugees, and the overall cost of global warming.

It puts the overall cost at less than 2% of GDP for a 2.5 degrees Centigrade (or 4.5 degrees Fahrenheit) temperature increase during this century. This is vastly less than the much heralded prediction of Lord Stern, who said climate change would cost 5%-20% of world GDP in his influential 2006 report for the British government.  (See WUWT report about Stern who gets asked some tough questions by Australia’s ABC)

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In climate science, the real debate has never been between “deniers” and the rest, but between “lukewarmers,” who think man-made climate change is real but fairly harmless, and those who think the future is alarming. Scientists like Judith Curry of the Georgia Institute of Technology and Richard Lindzen of MIT  have moved steadily toward lukewarm views in recent years.

Even with its too-high, too-fast assumptions, the recently leaked draft of the IPCC impacts report makes clear that when it comes to the effect on human welfare, “for most economic sectors, the impact of climate change will be small relative to the impacts of other drivers,” such as economic growth and technology, for the rest of this century. If temperatures change by about 1C degrees between now and 2090, as Mr. Lewis calculates, then the effects will be even smaller.

Indeed, a small amount of warming spread over a long period will, most experts think, bring net improvements to human welfare. Studies such as by the IPCC author and economist Professor Richard Tol of Sussex University in Britain show that global warming has probably done so already. People can adapt to such change—which essentially means capture the benefits but minimize the harm. Satellites have recorded a roughly 14% increase in greenery on the planet over the past 30 years, in all types of ecosystems, partly as a result of man-made CO2 emissions, which enable plants to grow faster and use less water.

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I liked this part the best:

Almost every global environmental scare of the past half century proved exaggerated including the population “bomb,” pesticides, acid rain, the ozone hole, falling sperm counts, genetically engineered crops and killer bees. In every case, institutional scientists gained a lot of funding from the scare and then quietly converged on the view that the problem was much more moderate than the extreme voices had argued. Global warming is no different.

Full article here:

http://online.wsj.com/news/articles/SB10001424052702303725404579460973643962840?mg=reno64-wsj&url=http%3A%2F%2Fonline.wsj.com%2Farticle%2FSB10001424052702303725404579460973643962840.html

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Indeed, so many environmental scares have gone the way of the dodo, and yet here we are again, watching some people freak out about another one, and with wholesale planetary warming not cooperating as predicted, they are starting to see climate bogey-men in every weather event. It seems the fear of weather from the dark ages has returned to the mindset of some irrational thinkers.

This one little fact though is a deal breaker for alarm:

It puts the overall cost at less than 2% of GDP for a 2.5 degrees Centigrade (or 4.5 degrees Fahrenheit) temperature increase during this century.

Hang on to that thought, James Delingpole  writes:

Previous reports – notably the hugely influential 2006 Stern Review – have put the costs to the global economy caused by ‘climate change’ at between 5 and 20 percent of world GDP.

But the latest estimates, to be published by Working Group II of the IPCC’s Fifth Assessment Report, say that a 2.5 degrees Celsius rise in global temperatures by the end of the century will cost the world economy between just 0.2 and 2 percent of its GDP.

If the lower estimate is correct, then all it would take is an annual growth rate of 2.4 percent (currently it’s around 3 percent) for the economic costs of climate change to be wiped out within a month.

Ouch. Game over for climate alarm.