Friday, April 6, 2012

Sea levels rose 15 times faster 14,600 years ago

According to a paper just published in Nature, global sea levels rose between 14 to 18 meters over a period of not more than 340 years during the last deglaciation from 14,650 to 14,310 years ago. This equates to ~0.47 m/yr or 47 mm/yr, an entirely natural change more than 15 times faster than the 3.1 mm/yr rate of global sea level rise reported since 1993.

Global Warming In 12,000 B.C.

By News Account

Created Apr 6 2012 - 5:00pm

A dramatic sea-level rise occurred at the onset of the first warm period of the last deglaciation, known as the Bølling warming, approximately 14,600 years ago. This event, referred to as Melt-Water Pulse 1A (MWP-1A), corresponds to a rapid collapse of massive ice sheets 14,600 years ago and resulted in global sea-level rise of ~14 m.

The Tahiti Sea-Level Expedition 310 of the Integrated Ocean Drilling Program (IODP) was carried out in 2005 by the European Consortium for Ocean Research Drilling (ECORD) and the ECORD Science Operator (ESO) on behalf of IODP.

Using uranium-thorium(U-th) dating of coral samples obtained from cores drilled in the Tahiti coral reefs, the researchers were able to reconstruct sea-level rise over the last deglaciation because coral is extremely sensitive to sea-level changes and fossilized corals are therefore an excellent indicator for sea-level changes over time.

They found that most of the melting water that contributed to MWP-1A was sourced from the Antarctic ice sheet, highlighting dynamical behaviour of this ice sheet in the past. The authors note that further research is needed using cored fossilized corals to better understand the sequence of events related to ice sheet collapse during the last deglaciation. Today, half of world's population, approximately 3.2 billion people, lives within 200 km of coastline, and a tenth of the population lives less than 10 meters above sea level.

Don't let the Yankees cap detract from the quality of the study.

"Corals are outstanding archives to reconstruct past sea-level changes as they can be dated to within plus or minus 30 years stretching back thousands of years. Moreover, Tahitian reefs are ideally located to reconstruct the deglacial sea-level rise and to constrain short-term events that are thought to have punctuated the period between the Last Glacial Maximum and the present days. Tahiti is located at a sufficiently considerable distance from the major former ice sheets to give us close to the average of sea levels across the globe, as a non-volcanic island it is also subsiding into the ocean at a steady pace that we can easily adjust for." said Pierre Deschamps of CEREGE (UMR Aix-Marseille Univ. - CNRS - IRD - College de France), first author of the study. "Insights into past sea-level changes may help to better constrain future changes. Our work sheds light onto an extreme event of rise in global sea levels in which ice-sheet collapse coincided with a rapid warming. Whether the freshwater pulse was a result of an already warming word or helped to warm the climate is currently unclear. However, our finding will help scientists currently modeling future climate change scenarios to factor in the dynamic behaviour of major ice sheets and finally to provide more reliable predictions of ice sheet responses to a warming climate".

The dynamics of sea-level change in response to massive water discharge - and if that will even happen - contains a lot of unknowns. IODP Expedition 310 helped international scientists shed light on one of the most important climate event of the last deglaciation, the MWP-1A event.

Citation: Pierre Deschamps, Nicolas Durand, Edouard Bard, Bruno Hamelin, Gilbert Camoin, Alexander Thomas, Gideon Henderson, Jun’ichi Okuno, Yusuke Yokoyama, 'Ice-sheet collapse and sea-level rise at the Bølling warming 14,600 years ago', Nature 483, 559–564 (29 March 2012) doi:10.1038/nature10902

Ice-sheet collapse and sea-level rise at the Bølling warming 14,600 years ago

Nature 483, 559–564 (29 March 2012) doi:10.1038/nature10902

Received
Accepted
Published online

Abstract

Past sea-level records provide invaluable information about the response of ice sheets to climate forcing. Some such records suggest that the last deglaciation was punctuated by a dramatic period of sea-level rise, of about 20 metres, in less than 500 years. Controversy about the amplitude and timing of this meltwater pulse (MWP-1A) has, however, led to uncertainty about the source of the melt water and its temporal and causal relationships with the abrupt climate changes of the deglaciation. Here we show that MWP-1A started no earlier than 14,650 years ago and ended before 14,310 years ago, making it coeval with the Bølling warming. Our results, based on corals drilled offshore from Tahiti during Integrated Ocean Drilling Project Expedition 310, reveal that the increase in sea level at Tahiti was between 12 and 22 metres, with a most probable value between 14 and 18 metres, establishing a significant meltwater contribution from the Southern Hemisphere. This implies that the rate of eustatic sea-level rise exceeded 40 millimetres per year during MWP-1A.

Gore's Current TV now claims its former anchor 'specialized in pounding the table' without facts on his side

Olbermann Trades Lawsuits, Insults With Gore's Current TV

Friday, April 6, 2012

(Updates with countersuit in second paragraph.)

April 6 (Bloomberg) --Keith Olbermann and former Vice President Al Gore's Current TV LLC filed lawsuits against each other after the anchor's firing last month from the progressive political cable channel.

Olbermann, 53, filed a breach-of-contract complaint yesterday in Los Angeles Superior Court, saying he "was disheartened to discover Al Gore, Joel Hyatt, and the management of Current are no more than dilettantes portraying entertainment industry executives." Current TV filed a countersuit today.

Olbermann clashed with producers at the channel this year, refusing to anchor election segments and taking himself off the air. Current TV said on March 30 that it had dismissed Olbermann because he no longer represented the channel's values.

"Current's sudden and public termination of Olbermann was the latest in a series of increasingly erratic and unprofessional actions undertaken by Current's senior management," according to the former anchorman's complaint, which seeks unspecified damages.

In its breach-of-contract complaint, filed in the same court, Current TV said that on April 3 the former anchor appeared on the "Late Show with David Letterman" where he said that his termination was "my fault" and that "I screwed up." Such admissions appear nowhere in his lawsuit, Current TV said.

'Falsehoods and Distortions'

Olbermann's complaint is "riddled with falsehoods and distortions in which he refused to take any responsibility whatsoever for that termination," according to Current TV.

"Current seeks a determination that it is no longer obligated to pay a dime to Mr. Olbermann who, having already been paid handsomely for showing up sporadically and utterly failing to keep his end of the bargain, now seeks to be paid tens of millions more for not working at all," the channel said in its complaint.

The channel replaced Olbermann with former New York Governor Eliot Spitzer on a new show, "Viewpoint with Eliot Spitzer."

Current TV has 68.5 million subscribers and estimated net operating revenue of $127 million for 2012, according to researcher SNL Kagan.

Suspension Over Donations

Olbermann, who left MSNBC in 2011 after serving a two-day suspension over political donations, received equity in New York-based Current Media, according to a statement at the time.

"As the old adage says: 'When the law is on your side, you argue the law. When the facts are on your side, you argue the facts. When neither the law nor the facts are on your side, you pound the table,''' Laura Nelson, a Current TV spokeswoman, said in a statement yesterday. ''It is well established that over his professional career Mr. Olbermann has specialized in pounding the table.''

Olbermann's lawyer, Patricia Glaser, said today in a phone interview that Current TV's lawsuit had no merit and posed no problem for her client.

In a post on Twitter, Olbermann wrote: "After reading the @Current filing my attorneys and I think it should be subtitled 'How to Try To Pound The Table...And Miss.'"

Olbermann's case is Olbermann Broadcasting Empire v. Current TV; the cross-complaint is Current TV, LLC v. Olbermann Broadcasting Empire, BC482335, California Superior Court (Los Angeles).

New paper finds Arctic Ocean warming is from geothermal heat

A paper published today in Geophysical Research Letters titled "The Arctic Ocean warms from below" finds that geothermal heat at the bottom of the Arctic Ocean caused slight warming of 0.004C per year from 1993-2010. The authors find a temperature inversion with higher temperatures at the bottom of the ocean than the interior, which indicates the heat had to arise from geothermal sources; the opposite temperature profile would be expected if the Arctic Ocean was heating from above due to greenhouse gases. Other than the fact that heat rises, the paper throws more water on Trenberth's claim that his 'missing heat' allegedly from greenhouse gases has sunken to the bottom of the ocean.

GEOPHYSICAL RESEARCH LETTERS, doi:10.1029/2012GL050890

The Arctic Ocean warms from below

Key Points

The deep water is warming at a measurable rate of ~ 0.0004 {degree sign}C yr-1
This heating is not escaping along the basin perimeter
A greater fraction of the heat escapes vertically than previously thought

Authors:

Eddy C Carmack

William James Williams

Sarah Zimmermann

Fiona A. McLaughlin

The old (~450-year isolation age) and near-homogenous deep waters of the Canada Basin (CBDW), that are found below ~2700 m, warmed at a rate of ~0.0004 {degree sign}C yr-1 between 1993 and 2010. This rate is slightly less than expected from the reported geothermal heat flux (Fg ~ 50 mW m-2). A deep temperature minimum Tmin layer overlies CBDW within the basin and is also warming at approximately the same rate, suggesting that some geothermal heat escapes vertically through a multi-stepped, ~300-m-thick deep transitional layer. Double diffusive convection and thermobaric instabilities are identified as possible mechanisms governing this vertical heat transfer. The CBDW found above the lower continental slope of the deep basin maintains higher temperatures than those in the basin interior, consistent with geothermal heat being distributed through a shallower water column, and suggests that heat from the basin interior does not diffuse laterally and escape at the edges.

Thursday, April 5, 2012

Paper: Temperature records show 'predominantly natural fluctuations'

Published this week in the NIPCC Report:

One Hundred Years of Global Temperature Change

Reference: Ludecke, H.-J., Link, R. and Ewert, F.-K. 2011. How natural is the recent centennial warming? An analysis of 2249 surface temperature records. International Journal of Modern Physics C 22: 10.1142/S0129183111016798.

Working with 2249 globally-distributed monthly temperature records covering the period 1906-2005, which they obtained from NASA's Goddard Institute for Space Studies, Ludecke et al. (2011) evaluated "to what extent the temperature rise in the past 100 years was a trend or a natural fluctuation."

According to the authors, "the mean of all stations shows 0.58°C global warming from 1906 to 2005," but they say that "if we consider only those stations with a population of under 1000 and below 800 meters above sea level, this figure drops to 0.41°C." In addition, they note that "about a quarter of all records show falling temperatures," which in itself, in their words, "is an indication that the observed temperature series are predominantly natural fluctuations," where the word natural means that "we do not have within a defined confidence interval a definitely positive anthropogenic contribution." And continuing to explore this aspect of their analysis, they evaluated - with a confidence interval of 95% - the probability that the observed global warming from 1906 to 2005 was a natural fluctuation, finding that probability to lie "between 40% and 70%, depending on the station's characteristics," while "for the period 1906 to 1955 the probabilities are arranged between 80% and 90% and for 1956 to 2005 between 60% and 70%."

Based on their several findings, the authors write in the final sentence of the abstract of their paper that the strongest statement they can make on the subject is that "only a marginal anthropogenic contribution cannot be excluded," which suggests to us that if there is a CO2-induced warming signal hidden somewhere in the global temperature data of the Goddard Institute for Space Studies, it must be relatively small, as is suggested by the observation-based analyses of Idso (1998), Lindzen and Choi (2009, 2011) and Scafetta (2012).

Additional References

Idso, S.B. 1998. CO2-induced global warming: a skeptic's view of potential climate change. Climate Research 10: 69-82.

Lindzen, R.S. and Choi, Y.-S. 2009. On the determination of climate feedbacks from ERBE data. Geophysical Research Letters 36: 10.1029/2009GL039628.

Lindzen, R.S. and Choi, Y.-S. 2011. On the observational determination of climate sensitivity and its implications. Asia-Pacific Journal of Atmospheric Sciences 47: 377-390.

Scafetta, N. 2012. Testing an astronomically based decadal-scale empirical harmonic climate model versus the IPCC (2007) general circulation climate models. Journal of Atmospheric and Solar-Terrestrial Physics: 10.1016/j.jastp.2011.12.005.

European carbon prices tumble to record low

As Carbon Prices Sink, Unease Rises

By SELINA WILLIAMS And ALESSANDRO TORELLO WSJ.COM 4/5/12

LONDON—The market for carbon emissions is running out of gas.

Prices of emission allowances, which award the holder the right to release carbon dioxide into the atmosphere, have tumbled this week to a record low. They are down 11% from the start of the year and now trade at less than one-fourth of their July 2008 value.

The latest blow came Monday, when the European Union released preliminary data showing its carbon emissions fell by a larger-than-expected amount last year. While decreasing amounts of pollution out of Europe are a boon for the environment, it raises questions about the viability of a market that was hailed as a forerunner for the rest of the world.

"The price level reflects a lack of confidence in the tool," said Emmanuel Fages, head of power, gas, carbon and coal research at Société Générale Commodities in Paris.

The decline in prices comes as investors continue to retrench from the market. Hopes that other nations, such as the U.S., would adopt the EU model have been dashed, and international climate talks have made slow progress on a global consensus. Trading desks have been scaled back, and banks, which previously had been big players in the market, are no longer making big bets.

Under a system known as "cap and trade," the European Union in 2005 launched trading in these allowances after putting a cap on the amount of carbon dioxide or similar gases that certain sectors, such as utilities, could emit. The idea was to encourage investment in clean-energy technologies and cleaner-burning fuels. Companies that came in below their caps could sell their allowances on the open market and make a profit.

But lately, things haven't been going according to plan. As Europe's economy has contracted, big emitters such as power plants have been operating at slower rates and releasing less gas. With less demand for these allowances, a glut in supply has emerged, driving prices down. On Wednesday, prices for allowances on ICE Futures Europe finished 2.2% lower, at €6.21 ($8.22) a metric ton of carbon dioxide after sliding as low as €5.99. Prices are down about 65% over the past year.

The collapse in prices has cast doubt on whether the system can withstand a prolonged economic slump and about whether the EU can muster the political will to bolster prices. Some analysts expect the supply glut to worsen. Deutsche Bank boosted its estimate of the oversupply by 2020 by more than 50%, to 1.063 billion allowances.

"The magnitude of this projected surplus out to 2020 underlines the urgent need for action to be taken by the EU authorities to re-establish scarcity" in the emissions-trading system, known as ETS, said Mark Lewis, head of energy research at Deutsche Bank.

The move is gaining ground in Brussels, with the European Commission, the European Parliament and a number of industrial companies in favor of actions to prop up prices. The most probable option would be the withdrawal of permits from the ETS, effectively causing a shortage to boost prices. That action essentially would have the effect of pushing some companies to develop clean-energy technologies.

Some companies that favor intervention have drafted strategies around the ETS and need to get a return on their investments. Others, like Royal Dutch Shell PLC, promote clean technologies that have a future only with high emission-allowance prices. "The economic crisis has significantly impacted the effectiveness of the EU ETS," said David Hone, Shell's climate-change adviser. "The [carbon dioxide] price is currently too low to drive the development of low-carbon technologies. For the EU to meet its longer-term climate-change goals, the [carbon dioxide] price in Europe today needs to be strengthened."

To be sure, there still are some signs of life. CME Group Inc. said Tuesday that it would buy out its partners in the Green Exchange, which runs emissions-trading platforms in Europe and the U.S. Trading volumes in Europe are up this year as utilities and other businesses buy allowances ahead of a change in the rules that foresees fewer handed out free next year. Under an overhaul of the ETS scheduled for 2013, more industrial sectors, such as producers of petrochemicals, ammonia and aluminum, would be required to comply with emissions caps.

But there are some who are opposed to changing the trading system. Action "would create a risky precedent in trying to manipulate a market-based mechanism," said William Garcia, executive director for energy at Cefic, an EU chemicals lobby group in Brussels, adding that it would undermine the credibility of the system. "The ETS is not broken, it's delivering what's supposed to."

The fall in prices has created incentives for burning more coal for electricity generation in Europe. According to the U.K.'s natural gas and power network operator, National Grid PLC, coal accounted for 46% of generation in the first quarter of this year compared with 26% for natural gas. That is a higher percentage for coal compared with previous quarters.

Analysts say carbon prices would need to be at about €15 a ton to encourage the switch out of coal into natural gas. Market observers are awaiting a June 15 Council of Energy Ministers meeting to see if the EU is serious about withdrawing allowances in order to drive up prices.

Poland recently vetoed nonbinding goals that would lead the EU to meet an agreed target of cutting carbon dioxide emissions by at least 80% by 2050.

"This year is the most legitimate opportunity to fix the market, but the window of opportunity is rapidly closing," said Damien Morris, senior policy adviser for U.K.-based climate group Sandbag.

Wednesday, April 4, 2012

New paper finds climate variation due to tilt & rotation of Sun & Moon

A paper published today in the Journal of Geophysical Research associates climate variation, such as the El Niño–Southern Oscillation [ENSO], "with the obliquity [tilt] and revolution velocity of the Sun and Moon; the speed of geophysical fluids; and the latitude, radius, and rotation velocity of Earth." The authors find climate cycles lasting from days to years may be related to this natural mechanism.

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 117, D07102, 20 PP., 2012
doi:10.1029/2011JD016967

Sun-Moon gravitation-induced wave characteristics and climate variation

Key Points

Sun-Moon gravitation drives nonlinear motions of geophysical fluids
The motions demonstrate the climate variations with abundant periods
Earth's rotation helps fluids remember and accumulate momentum on multiple time scales

Zhiren Wang et al

Understanding periods associated with climate variations has been challenging and has attracted scientific study. In the work presented here, we establish a theoretical dynamical model driven by Sun-Moon gravitation (SMG) and present basic SMG wave characteristics and SMG-induced nonlinear motions for geophysical fluids. As compared to observations, waves and motions demonstrate climate variations associated with abundant structures and climatic rhythms, including the 30–60 day oscillation, seasonality, El Niño–Southern Oscillation–like interannual variation, etc. In our work, periods depended upon the obliquity and revolution velocity of the Sun and Moon; the speed of geophysical fluids; and the latitude, radius, and rotation velocity of Earth. The rotation of Earth helps fluids remember and accumulate momentum in geophysical fluids that are provided by the SMG on multiple time scales, which may contribute to multiperiods of climate oscillations. The speed-dependent periods of SMG-induced flow are of a broad spectrum (i.e., faster speeds, shorter periods). SMG-induced flow in an atmosphere of faster flow tends to have shorter (e.g., seasonal and annual) periods, while an ocean of slower flow tends to have longer (e.g., annual and interannual) periods.

How to 'look cool' by supporting climate fraudster Michael Mann

The Climate Science Legal Defense Fund is now hawking t-shirts and even a signed hockey stick to support climate fraudster Michael Mann. For a $25 donation you can score a "cool" t-shirt saying "100% dolphin-safe coal-fired power plant" or "I Sulfur when you Argon." A $300 donation proffers a hockey stick signed by the Mann himself.

Support Climate Scientists & Look Cool Doing So!

'Cool" Items

Help the Climate Science Legal Defense Fund (CSLDF) raise money to cover the costs of Dr. Mann’s legal defense as well as other scientists who face similar challenges. To help raise money and reward those that contribute, we have rounded up some cool designs and gifts. CSLDF thanks Nicole Martinez and Lunchbreathwho were kind enough to donate their designs for this fundraiser.

$25 gets you one of our t-shirts. They will be delivered a couple weeks after the fundraiser is over. We will check in with you about which design you want and what size.

$50 gets two of the t-shirts.

$75 gets all three of the t-shirts and our true gratitude.

$150 gets you all three of the t-shirts and a copy of Climate Change: Picturing the Science signed by Joshua Wolfe (www.picturingclimatechange.com)

$300 gets you a hockey stick signed by Mike Mann.

$1000 gets you a 16×20 signed silver gelatin print by Joshua Wolfe.

FOR MORE INFORMATION AND TO GET THESE COOL ITEMS PLEASE VISIT: http://www.rockethub.com/projects/6884-help-cover-mike-mann-s-legal-bills

Cheap synthetic fertilizer, a boon to agriculture, is allegedly causing global warming

A report today alleges increased use of inexpensive and highly-effective synthetic fertilizer, which has boosted "food production all over the world" due to its high nitrogen content, could be "to blame for global warming." The press release from UC Berkeley proclaims, “limiting [use of the high nitrogen content synthetic fertilizer] can buy us a little more time in figuring out how to reduce CO2 emissions," which along with nitrogen is the primary source of plant nutrition.

Is Fertilizer To Blame For Global Warming?

April 4, 2012

Chemists from the University of California, Berkeley have discovered evidence of a link between increased fertilizer use and a rise in atmospheric nitrous oxide, a major greenhouse gas.

Climate scientists have long assumed the cause of rising nitrous oxide levels in the atmosphere was due in part to nitrogen-based fertilizers. Such fertilizers are used to stimulate microbes in the ground to convert nitrogen to nitrous oxide at a faster rate.

Published in the April issue of the journal Nature Geoscience, the new study uses nitrogen isotope data to pinpoint direct blame on these nitrogen rich fertilizers.

“Our study is the first to show empirically from the data at hand alone that the nitrogen isotope ratio in the atmosphere and how it has changed over time is a fingerprint of fertilizer use,” said study leader Kristie Boering, a UC Berkeley professor of chemistry and of earth and planetary science, according to a Berkeley press release.

“We are not vilifying fertilizer. We can’t just stop using fertilizer,” she added. “But we hope this study will contribute to changes in fertilizer use and agricultural practices that will help to mitigate the release of nitrous oxide into the atmosphere.”

Nitrous oxide is the most potent of the greenhouse gasses, trapping heat and contributing to global warming. Nitrous oxide has also been found to destroy the stratospheric zone, which protects the Earth from ultraviolet rays.

These levels have been dramatically increased in the past 50 years, according to the study. Part of this increase coincided with the new “green” movement of the 1960s. As global population increased, cheap and synthetic fertilizers became widely available, boosting food production all over the world.

Boering and colleagues, former UC Berkeley graduate students Sunyoung Park and Phillip Croteau, gathered their samples from Antarctic ice, or “firn air,” dating from 1940-2005 as well as at an atmospheric monitoring station at Cape Grim in Tasmania.

Analysis of this data revealed a previously discovered seasonal cycle. What surprised these researchers, however, were the isotopic measurements found by a sensitive isotope ratio mass spectrometer. The measurements also discovered a seasonal cycle, something the spectrometer had not done before. At Cape Grim, the seasonal cycle is due in part to the circulation of air returning from the stratosphere, where nitrous oxide is destroyed after an average of 120 years, and seasonal changes in the ocean.

“The fact that the isotopic composition of N2O shows a coherent signal in space and time is exciting, because now you have a way to differentiate agricultural N2O from natural ocean N2O from Amazon forest emissions from N2O returning from the stratosphere,” Boering said. “In addition, you also now have a way to check whether your international neighbors are abiding by agreements they’ve made to mitigate N2O emissions.”

Using these results, the UC Berkeley students are suggesting a limiting of nitrous oxide emissions, like those found in fertilizer, could be a first step in reducing greenhouse gasses and the effects of global warming.

According to a Berkeley press release about these findings, Boering said, “Limiting N2O emissions can buy us a little more time in figuring out how to reduce CO2 emissions.”

Source: redOrbit (http://s.tt/18Nza)

Scheme to fix hoax CO2 problem would 'require the largest industry ever'

According to "back of the envelope" calculations presented at a conference last week, scrubbing the atmosphere of the trace, harmless, life-sustaining gas CO2 would require an industry "1000 times larger than any existing industry" and could deprive an additional 53 million people of water. According to the report in New Scientist, "some schemes to save the Earth just might cost the Earth."

Stripping CO₂ from air requires largest industry ever

04 April 2012 New 'Scientist'

SOME schemes to save the Earth just might cost the Earth. Back-of-the-envelope calculations suggest that scaling up proposals to scrub the atmosphere of carbon dioxide would mean creating the biggest industry there has ever been.

You can strip CO₂ from the air with chemical filters or by boosting reactions occurring as rocks weather. Colin Axon of Brunel University in Uxbridge, UK, and Alex Lubansky at the University of Oxford estimated what it would take to remove the 30 gigatonnes of CO₂ we emit every year.

That would mean processing 75,000 Gt of dry air. Scaling up proposals to filter air would use 180 Gt of clean water per year, depriving 53 million people of water, on top of the 66 per cent of the world's population who will face water shortages by 2025.

Enhancing rock weathering is no better. It would call for 100 Gt of olivine, a common mineral. This is 12,500 times more than is produced worldwide. To deal with 30 Gt of CO₂ we would need to spread the olivine 1 centimetre thick over 3.6 billion square kilometres of dry land, 1000 times more than Earth has available.

Axon says his calculations are rough. "Still, I'm confident that a CO₂ removal scheme would have to be in the order of 1000 times larger than any existing industry." He presented the estimates at the Planet Under Pressure conference in London last week.

New paper finds significant, natural decrease in cloudiness over past 50 years

A paper published last week finds that cloud cover over China significantly decreased during the period 1954-2005. This finding is in direct contradiction to the theory of man-made global warming which presumes that warming allegedly from CO2 'should' cause an increase in water vapor and cloudiness. The authors also find the decrease in cloud cover was not related to man-made aerosols, and thus was likely a natural phenomenon, potentially a result of increased solar activity via the Svensmark theory or other mechanisms. As climatologist Dr. Roy Spencer has pointed out his book,

"The most obvious way for warming to be caused naturally is for small, natural fluctuations in the circulation patterns of the atmosphere and ocean to result in a 1% or 2% decrease in global cloud cover. Clouds are the Earth’s sunshade, and if cloud cover changes for any reason, you have global warming — or global cooling."

Ann. Geophys., 30, 573-582, 2012
www.ann-geophys.net/30/573/2012/
doi:10.5194/angeo-30-573-2012

Significant decreasing cloud cover during 1954–2005 due to more clear-sky days and less overcast days in China and its relation to aerosol

X. Xia
LAGEO, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China

Abstract. An updated analysis of cloud cover during 1954–2005 in China was performed using homogeneous cloud cover data from 314 stations. Long-term changes in frequencies of different cloud cover categories and their contributions to long-term changes in cloud cover were assessed. Furthermore, aerosol effects on cloud cover trends were discussed based on comparison of cloud cover trends in polluted and mildly polluted regions. Frequencies of clear sky (cloud cover <20%) and overcast days (cloud cover >80%) were observed to increase by ~2.2 days and decrease by ~3.3 days per decade, respectively, which accounts for ~80% of cloud cover reduction. Larger decreasing trends in cloud cover due to larger increase in clear sky frequency and larger decreases in overcast frequency were observed at stations with lower aerosol optical depth. There is no significant difference in trends regarding cloud cover, clear sky frequency, and overcast frequency between mountain and plain stations. These results are inconsistent with our expectation that larger decreasing trends in cloud cover should have been observed in regions with higher aerosol loading where more aerosols could lead to stronger obscuring effect on ground observation of cloud cover and stronger radiative effect as compared with the mildly polluted regions. Aerosol effect on decreasing cloud cover in China appear not to be supported by this analysis and therefore, further study on this issue is required.

Full Article (PDF, 2756 KB)