Planet Gore

Why Is the Glass Always Half Empty?

Bjørn Lomborg in the Japan Times today, wondering why climate reporting never looks at the bright side of life:

Have you noticed how environmental campaigners almost inevitably say that not only is global warming happening, but that what we are seeing is even worse than expected?

This is odd, because any reasonable understanding of how science proceeds would expect that, as we refine our knowledge, we find that things are sometimes worse and sometimes better than we expected, and that the most likely distribution would be about 50-50. Environmental campaigners, however, almost invariably see it as 100-0.
If we are regularly being surprised in just one direction, if our models get blindsided by an ever-worsening reality, it does not bode well for our scientific approach. Indeed, one can argue that if the models are constantly inaccurate, it is probably because the models are wrong. And if we cannot trust our models, we cannot know what policy action to take if we want to make a difference.
Yet, if new facts constantly show us that the consequences of climate change are getting worse and worse than expected, high-minded arguments about the scientific method appear to carry little weight. Certainly, this seems to be the prevailing bet in the spin on global warming. It is, again, worse than we thought, and despite our failing models, we will gamble on knowing just what to do: Cut CO2 emissions dramatically.
But it is simply incorrect to claim that climate data are systematically worse than expected; in many respects, they are spot on, or even better than expected. That we hear otherwise is an indication of the media’s addiction to worst-case scenarios, but that makes a poor foundation for smart policies.
The most obvious point about global warming is that the planet is heating up. It has warmed about 1 degree Celsius over the past century, and is predicted by the U.N. climate panel (IPCC) to warm 1.6 to 3.8 C during this century, mainly owing to increased CO2. An average of all 38 available standard runs from the IPCC shows that models expect a temperature increase in this decade of about 0.2 C.
But this is not at all what we have seen. And this is true for all surface temperature measures, and even more so for satellite measures. Temperatures in this decade have not been worse than expected; in fact, they have not even been increasing. They have actually decreased by between 0.01 and 0.1 C per decade. When it comes to temperature development, one of the most important indicators of global warming, we ought to be hearing that the data are actually much better than expected.

Likewise, and arguably much more importantly, measurements have shown that the heat content of the world’s oceans has also been dropping for the past four years. Whereas energy in terms of temperature can disappear relatively easily from the light atmosphere, it is unclear where the heat from global warming should have gone — and certainly this is again much better than expected.

We constantly hear how the Arctic sea ice is disappearing faster than expected, and this is true. But most serious scientists also allow that global warming is only part of the explanation. They also take into account the so-called Arctic Oscillation of atmospheric pressure over the Arctic Ocean, which is now in a state that prevents buildup of old ice and creates winds that immediately flushes most ice into the North Atlantic.
In 2007, The Associated Press, along with many other news outlets, told us that the “Arctic is screaming” and that the Northwest Passage was open “for the first time in recorded history.” Yet the BBC reported in 2000 that the fabled Northwest Passage was already without ice.
We rarely hear that the Antarctic sea ice is not in decline or that it is above average for the past year. IPCC models would expect declining sea ice in both hemispheres, but in fact where the Arctic is doing worse than expected, Antarctica is doing better.
Instead, we are inundated with stories of how sea levels will rise, and how one study after another finds that it will be much worse than what the IPCC predicts. Most models, however, find results within the IPCC range of a sea-level increase of 18 to 59 centimeters this century. This is of course why the thousands of IPCC scientists projected that range. Studies claiming one meter or more, however, obviously make for better headlines.
Since 1992, we have had satellites measuring the rise in global sea levels, and they have shown a stable increase of 3.2 mm — spot on the IPCC projection. Moreover, over the last two years, sea levels have not increased at all — actually, they have shown a slight drop. Should we not be told that this is much better than expected?
Hurricanes were the stock image of Al Gore’s famous film on climate change, and certainly the United States took a battering in 2004 and 2005, which lead to wild claims of ever stronger and costlier storms in the future. But in the two years since, the damage has been well below average, virtually disappearing in 2006. That is definitely better than expected.
Gore quoted MIT hurricane researcher Kerry Emmanuel to support an alleged scientific consensus that global warming is making hurricanes much more severe. But Emmanuel has now published a new study showing that even in a dramatically warming world, hurricane frequency and intensity may not substantially rise during the next two centuries. That conclusion did not get much exposure in the media.
Of course, not all things are less bad than we thought. But one-sided exaggeration is not the way forward. We urgently need balance if we are to make sensible choices.


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