The long pause in warming confirmed

20/10/2011

Climate Change – News and Comments

Nice research, curious rhetoric

Just dis-embargoed at noon PST (8 pm BST) on 20 October are a press release and associated papers from the Berkeley Earth Surface Temperatures (BEST) project. A team led by Richard A. Muller has been asking whether the histories of land surface temperatures from the likes of NOAA, NASA and the Hadley Centre are to be trusted. Clever statistics glean and process raw data from 39,000 weather stations world wide – more than five times as many as used by other analysts.

The short answer is that the other histories are broadly validated, as seen in this graph from one of the new papers.

If your eye can trace the black line of the BEST study, based on a random selection of weather stations, you’ll see that the average temperatures of the land correspond quite well with the other series.

What’s very odd is the rhetoric of the press release. It begins:

Global warming is real, according to a major study released today. Despite issues raised by climate change skeptics, the Berkeley Earth Surface Temperature study finds reliable evidence of a rise in the average world land temperature of approximately 1°C since the mid-1950s.

Global warming real? Not recently, folks. The black curve in the graph confirms what experts have known for years, that warming stopped in the mid-1990s, when the Sun was switching from a manic to a depressive phase.

Elsewhere the press release first begs the question by calling the past 50 years “the period during which the human effect on temperatures is discernible” and then contradicts this by saying, What Berkeley Earth has not done is make an independent assessment of how much of the observed warming is due to human actions, Richard Muller acknowledged.”

Let me say there is interesting stuff in the material released today, particularly in the paper on Decadal Variations, tracing links with El Niño and other regional temperature oscillations” — a subject I may return to when I have more time.

It hasn’t escaped my attention that BEST is today gunning mainly for Anthony Watts and his Surface Stations project in the USA, but he’s well capable of answering for himself. See wattsupwiththat.com/2011/10/20/the-berkeley-earth-surface-temperature-project-puts-pr-before-peer-review/

Added 21 October: See this rather uneasy comment from Judith Curry, a member of the Berkeley teamhttp://judithcurry.com/2011/10/20/berkeley-surface-temperatures-released/

And later: New Scientist quotes me saying something similar to what’s above – followed of course by the usual grossly biased and poorly informed attempt at a put-down http://www.newscientist.com/article/dn21074-sceptical-climate-scientists-concede-earth-has-warmed.html

References

The BEST home page, with downloadable press release and papers, is here www.BerkeleyEarth.org

The graph shown above is Fig. 1 in “Decadal Variations in the Global Atmospheric Land Temperatures,” Richard A. Muller et al., unpublished


Amazon rainforest

19/07/2010

Predictions Revisited and Climate Change: News and Comments

Will the Amazon rainforest survive?

A flurry of stories about the rainforests confirms that the proper concern about tropical deforestation has been thoroughly confused by improper attempts to invoke man-made global warming. Before turning to thunderstorms felling trees,  let’s start with the big picture of expectations, past and present, for the Amazon rainforest. For more than 30 years, large-scale assessments have been based on satellite imagery, despite the problem that much of the forest is covered with clouds at any one time. Brazil’s own Instituto Nacional de Pesquisas Espaciais, INPE, has played a leading part.

In a forecast that proved wrong even more rapidly than The Population Bomb (see the previous post) an ecologist Philip Fearnside declared in 1982 that the Amazon forest was vanishing at an accelerating rate, with more than 40% to be gone by 1988. I told the tale in my 1991 book about remote sensing, Spaceship Earth, after visiting INPE in São Paulo.

During the 1980s Brazil found itself at war on two fronts. At home, the government tried to moderate the rate of clearances in the Amazonian forest, and police a frontier region as gun-happy as the old Wild West of the USA. Internationally, they had to deal with a rising chorus of criticism about the rate at which the forest was disappearing. In 1982, on the basis of INPE’s figures, predictions by an American scientist P.M. Fearnside amounted to a forecast that 44 per cent of the Amazonian forest would be lost by 1988.

The Brazilians greeted such estimates with frank disbelief. There then followed a contest between calculation and remote sensing to try to establish the true facts. …

In 1989, the World Bank published estimates indicating that 12 per cent of Legal Amazonia was already deforested by 1988. This was based on calculations from the state of affairs in 1980. By this time the Brazilians were growing very angry. Although the figure was far less than the Fearnside estimate, the fact that it came from the World Bank secured it a place in international environmental folklore. The Brazilians appealed again to the umpires in space: the unblinking instruments of the remote-sensing satellites.

At INPE, Roberto Pereira da Cunha decided to make a ‘wall-to-wall’ assessrnent of the deforestation in Legal Amazonia. As he remarked, ‘No one wants to do the dirty work of gathering the data. It is a very trivial task for scientists.’ Trivial, but not unlaborious. Pereira’s team assembled 234 Landsat scenes and selected for close interpretation 101 images that showed evidence of deforestation. From colour composites of three wavelength bands the scientists outlined the deforested patches, and used a grid to measure their areas. Images for different years established rates of deforestation.

The most important conclusion was that there was no acceleration: deforestation was proceeding at a more or less steady rate. As for the total recent deforestation up till the end of 1988, INPE’S answer was 5 per cent of the area of Legal Amazonia. Meanwhile, Fearnside had changed his forecast. His new figures indicated 7 per cent deforestation of Legal Amazonia by 1989 – a far cry from his 44 per cent figure of just 7 years earlier, and almost in line with INPE’s figure. In 1990 Jim Tucker and Chris Justice of NASA broadly confirmed the Brazilian result by a similar large-scale use of Landsat imagery, but with a different technique, using only a single infra-red channel.

So what do the umpires in space say now, two decades later?

Read the rest of this entry »


Fierce stellar black hole

07/07/2010

Pick of the pics

A fierce stellar black hole

To get this X-ray image, to be published in Nature tomorrow, NASA’s Chandra satellite stared at a galaxy 13 million light-years away in the Sculptor Constellation for a total of 14 hours. The tartan pattern of pixels is a symptom of the great distance. A stellar black hole, or microquasar, seen location-wise in blue (X-rays of 2-8 keV), is throwing out two huge jets of hot gas reaching to the yellow-red hot-spots (X-rays of lesser energy). The contour lines are for emissions from hydrogen atoms measured by the Cerro Tololo Inter-American Observatory. Other observations by the European Southern Observatory help to confirm that we’re seeing an exceptionally massive and greedy microquasar shedding much of its energy in the form of long jets of hot gas. From one jet end to the other is about 300 parsecs or 1000 light-years – roughly the distance from the Solar System to the bright stars of Orion.

Nigel Calder comments: Apologies for two brief “Pick of the pics” in a row. I’ve been busy with writing unrelated to this blog.

Reference

Manfred W. Pakull, Roberto Soria and Christian Motch, “A 300 parsec long jet-inflated bubble around a powerful microquasar in the galaxy NGC 7793”, Nature, 466, pp. 209–212, 8 July 2010. The text of the paper is available here: http://www.eso.org/public/archives/releases/sciencepapers/eso1028/eso1028.pdf


Planck’s whole sky

05/07/2010

Pick of the pics

Planck’s first overview of the cosmos

Credit: ESA / LFI and HFI Consortia

Microwaves from the entire sky, surveyed by Europe’s Planck spacecraft since August 2009, are here mapped in galactic coordinates. The centre of the Milky Way Galaxy, in Sagittarius, is in the middle. The ribbon of the Milky Way (the flat disc of the Galaxy) extends horizontally across the map, with Cygnus conspicuous towards the left and Orion towards the right. Streamers above and below the disc are regions of star formation. The more subtle mottled regions top and bottom show the cosmic microwave background, from the formation of the first atoms 400,000 years after the Big Bang. The strong microwaves from the Galaxy will have to be gauged and subtracted to reveal hidden parts of that background. Crucial for making the distinction is Planck’s range of nine different microwave frequencies, 30 to 850 Ghz, and its ability to measure the temperature of the sky to one-sixth of a degree.

In Magic Universe I call it “looking for the pattern on the cosmic wallpaper”. Named after the quantum theory pioneer, Planck is the successor to NASA’s WMAP mission. In 2003 WMAP returned wonderful information about the cosmic microwave background but did not quite pin down the theory of the Big Bang that best fits the facts. Maybe Planck will do that, and there seems little point in updating Magic Universe about the cosmic wallpaper until the full Planck results are in, after four surveys of the whole sky, in 2012.

George Efstathiou of Cambridge, the Planck Survey Scientist, says “It has taken sixteen years of hard work by many scientists in Europe, the USA and Canada, to produce this new image of the early Universe. Planck is working brilliantly and we expect to learn a lot about the Big Bang and the creation of our Universe.”

Reference for Efstathiou quote: UK Space Agency press release 5 July 2010.