Lockwood and Frolich state that from 1985, there is a discrepancy between solar activity, which decreased, and the global temperature, which increased. Hence, solar activity cannot explain the observed warming. This conclusion, however, is flawed for several reasons.

To begin with, L & W write that solar activity decreased after 1985. This may almost be correct for the sunspot number (which remained the same) and perhaps correct for other solar activity proxies, but this is not correct for the cosmic rays. The 1990 solar maximum caused a larger decrease in the cosmic ray flux, which implies that the temperature should have been higher in the 1990’s than in the 1980’s. This leaves a discrepancy between the solar maximum of 2001 which was weaker than the solar maximum of 1990, and the observed temperature increase.

So why has the temperature continued increasing even though the solar activity diminished? This has to do with the second point, which is very important, but totally ignored by L & F.

L & F assume (like many others before) that there should be a one-to-one correspondence between the temperature variations and solar activity. However, there are two important effects which should be considered and which arise because of the climate’s heat capacity (predominantly the oceans). First, the response to short term variations in the radiative forcings are damped. This explains why the temperature variations in sync with the 11-year solar cycle are small (but they are present at the level which one expects from the observed cloud cover variations… about 0.1°C). Second, there is a lag between the response and the forcing. Typically, one expects lags which depend on the time scale of the variations. The 11-year solar cycle gives rise to a 2 year lag in the 0.1°C observed temperature variations. Similarly, the response to the 20th century warming should be delayed by typically a decade. Climatologists know this very well (the IPCC report, for example, include simulation results for the many decades long response to a “step function” in the forcing, and climatologists talk about “global warming commitment” that even if the CO2 would stabilize, or even decrease, we should expect to see the “committed warming”, e.g., Science 307), but L & F are not climatologists, they are solar physicists, so they may not have grasped this point to the extent that they should have.

See whole blog here.

One tainted export from China can’t be avoided in North America—air. An outpouring of dust layered with man-made sulfates, smog, industrial fumes, carbon grit and nitrates is crossing the Pacific Ocean on prevailing winds from booming Asian economies in plumes so vast they alter the climate. These rivers of polluted air can be wider than the Amazon and deeper than the Grand Canyon.

This MODIS satellite image shows a larg area of dust over the Bo Hai Bay and Yellow Sea extending into Korea. It is likely from the Gobi Desert.

“There are times when it covers the entire Pacific Ocean basin like a ribbon bent back and forth,” said atmospheric physicist V. Ramanathan at the Scripps Institution of Oceanography in La Jolla, Calif.

Over the Pacific itself, the plumes are seeding ocean clouds and spawning fiercer thunderstorms, researchers at Texas A&M University reported in the Proceedings of the National Academy of Sciences in March.

The influence of these plumes on climate is complex because they can have both a cooling and a warming effect, the scientists said. Scientists are convinced these plumes contain so many cooling sulfate particles that they may be masking half of the effect of global warming. The plumes may block more than 10% of the sunlight over the Pacific. But while the sulfates they carry lower temperatures by reflecting sunlight, the soot they contain absorbs solar heat, thus warming the planet.

See full story here.

June 2007 was the coldest June recorded in Australia in the post?1950 period. It was also a notably wet month in most of northern Australia, as well as along many parts of the east coast. A number of unseasonable cloudbands affected the tropics, and the month was also notable for four major east coast lows forming off the coast of New South Wales and eastern Victoria during the month, bringing heavy rain to much of the region.

Maximum temperatures were particularly low in the tropics due to the influence of increased cloud cover, with both Queensland (anomaly ?3.01°C) and the Northern Territory (anomaly ?3.40°C) breaking regional records by substantial margins. There was an especially exceptional cold episode from 17?22 June which saw vast areas of tropical Queensland and the NT experienced their coldest day on record, with single-digit maxima as far north as Tennant Creek (8.0°C) and Mount Isa (9.4°C). It was also unusually cold further south in Queensland with a state record low maximum for June (4.9°C) set at Applethorpe.  See full report here.

The cold has continued into July with new records set. See Queensland breaks cold weather record.

Nigel Calder, former editor of The New Scientist and author of innumerable books and articles on science, including The Chilling Stars, in conversation with Pan Pantziarka.

London Book Review:
How do you respond to the paper by Lockwood and Froehlich, which claims to comprehensively ‘settle the debate’ on the cosmic ray hypothesis you describe in The Chilling Stars?

Nigel Calder:
How often we’ve heard it before, that the debate has been settled! But this is an interesting case because these scientists accept that the Sun has played a big part in climate change over hundreds and thousands of years, just as we explain in the book. They even allow that it was involved in the warming in much of the 20th Century. And when Lockwood and Froehlich go on to say that the intensification of solar activity seen in the past hundred years has now ended, we don’t disagree with that. We part company only when they say that temperatures have gone on shooting up, so that the recent rise can’t have anything to do with the Sun, or with cosmic rays modulated by the Sun. In reality global temperatures have stopped rising. Data for both the surface and the lower air show no warming since 1999. That makes no sense by the hypothesis of global warming driven mainly by CO2, because the amount of CO2 in the air has gone on increasing. But the fact that the Sun is beginning to neglect its climatic duty—of batting away the cosmic rays that come from ‘the chilling stars’—fits beautifully with this apparent end of global warming.

Read whole interview here.

According to the headlines last week, the sun is not to blame for recent global warming: mankind and fossil fuels are. So Al Gore is correct when he said, “the scientific data is in. There is no more debate.” Of that the evangelical BBC had no doubt. There was an air of triumphalism in its coverage of the report by the Royal Society.

But there is a deeper and more worrying issue. Last week’s research is a simple piece of science and fundamentally flawed. Nobody looked beyond the hype; if they had, they would have reached a different conclusion.  The report argues that while the sun had a significant effect on climate during most of the 20th century, its influence is currently dwarfed by human effects. It says that all known solar influences since about 1990 are downward and because global temperature has increased since then, the sun is not responsible.

No. The research could prove the contrary. Using the global temperature data endorsed by the Inter-national Panel on Climate Change, one can reach a completely different conclusion.  Looking at annual global temperatures, it is apparent that the last decade shows no warming trend and recent successive annual global temperatures are well within each year’s measurement errors. Statistically the world’s temperature is flat. The world certainly warmed between 1975 and 1998, but in the past 10 years it has not been increasing at the rate it did.

My own view on the theory that greenhouse gases are driving climate change is that it is a good working hypothesis - but, because I have studied the sun, I am not completely convinced. The sun is by far the single most powerful driving force on our climate, and the fact is we do not understand how it affects us as much as some think we do. So look on the BBC and Al Gore with scepticism. A scientist’s first allegiance should not be to computer models or political spin but to the data: that shows the science is not settled. See full story here.