Climate Articles
Updates to model-data comparisons
It's worth going back every so often to see how projections made back in the day are shaping up. As we get to the end of another year, we can update all of the graphs of annual means with another single datapoint. Statistically this isn't hugely important, but people seem interested, so why not?
For example, here is an update of the graph showing the annual mean anomalies from the IPCC AR4 models plotted against the surface temperature records from the HadCRUT3v and GISTEMP products (it really doesn't matter which). Everything has been baselined to 1980-1999 (as in the 2007 IPCC report) and the envelope in grey encloses 95% of the model runs
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Greenhouse Gases: Who's Cheating?
The amounts of carbon in the atmosphere are out of whack with predictions and reported output
As the world gets serious about fighting climate change, a huge question looms: Are countries and companies really reducing their greenhouse gas emissions as much as they claim? The answer is crucial not just for the planet, but for business. The tighter the limits on emissions, the higher the price companies have to pay to pollute-and, conversely, the more profits some companies will reap by releasing less gas and monetizing the reductions under the umbrella of cap and trade. Considering the billions of dollars at stake, "can we really trust what's reported?" asks Pieter P. Tans, senior scientist at the National Oceanic & Atmospheric Administration's Earth System Research Laboratory in Boulder, Colo.
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The hottest decade ends and since there's no Maunder mininum - sorry deniers! - the hottest decade begins
2009 ends with a "sunspot surge" as solar cycle 24 revs up, though the sun is increasingly a bit player in the global warming trend
The 2000s were the hottest decade in recorded history by far - even though we're at "the deepest solar minimum in nearly a century." The 2000s were a full 0.2oC warmer than the 1990s, which of course had been the hottest decade on record, 0.14oC warmer than 1980s (according to the dataset that best tracks planetary warming). Hmm. It's almost like the warming is accelerating.
There's little doubt the 2010s will be the hottest decade on record, barring multiple supervolcanoes. Yet when the anti-science crowd isn't perversely spending their time trying to stop all efforts to cut global warming pollution that might slow warming, they are perversely trying to convince the public and policymakers we're not warming at all. That's why many of them have been rooting for this deep solar minimum to become a Maunder Minimum, to mute the warming signal and hence the motivation for action for a few more years. Yes, they have a self-destructive streak.
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How aircraft emissions contribute to warming
Aviation contributes up to one-fifth of warming in some areas of the Arctic.
The first analysis of emissions from commercial airline flights shows that they are responsible for 4-8% of surface global warming since surface air temperature records began in 1850 - equivalent to a temperature increase of 0.03-0.06 oC overall.
The analysis, by atmospheric scientists at Stanford University in Palo Alto, California, also shows that in the Arctic, aircraft vapour trails produced 15–20% of warming.
The results of this analysis are likely to be studied widely as nations attempt to address the impact of commercial aviation on global warming. There are around 35 million commercial airline flights every year. Studies have been conducted in Europe, with airlines coming under increased pressure as European Union leaders consider levying a carbon tax on aircraft emissions. But little research has been conducted on the topic in the United States.
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AGU stunner: Aircraft Vapor Trails Responsible for 15-20% of Arctic Warming
"If black-carbon emissions from aircraft could be reduced 20-fold, warming would be halted and a slight cooling would occur from plane-created vapour trails."
Nature (subs. req'd) reports on an analysis presented by Stanford's Mark Jacobson to the American Geophysical Union's annual meeting last week:
The first analysis of emissions from commercial airline flights shows that they are responsible for 4–8% of surface global warming since surface air temperature records began in 1850 - equivalent to a temperature increase of 0.03–0.06 oC overall.
The analysis, by atmospheric scientists at Stanford University in Palo Alto, California, also shows that in the Arctic, aircraft vapour trails produced 15–20% of warming.
This study is yet more strong evidence that we need a high priority global strategy to sharply reduce black carbon:
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Copenhagen: Things Fall Apart and an Uncertain Future Looms -- by bill mckibben
The Copenhagen summit turned out to be little more than a charade, as the major nations refused to make firm commitments or even engage in an honest discussion of the consequences of failing to act.
It's possible that human beings will simply never be able to figure out how to bring global warming under control - that having been warned about the greatest danger we ever faced, we simply won't take significant action to prevent it. That's the unavoidable conclusion of the conference that staggered to a close in the early hours of Saturday morning in Copenhagen. It was a train wreck, but a fascinating one, revealing an enormous amount about the structure of the globe.
Let's concede first just how difficult the problem is to solve - far more difficult than any issue the United Nations has ever faced. Reaching agreement means overcoming the most entrenched and powerful economic interests on Earth - the fossil fuel industry - and changing some of the daily habits of that portion of humanity that uses substantial amounts of oil and coal, or hopes to someday soon. Compared to that, issues like the war in Iraq, or nuclear proliferation, or the Law of the Sea are simple. No one really liked Saddam Hussein, not to mention nuclear war, and the Law of the Sea meant nothing to anyone in their daily lives unless they were a tuna.
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Finally, the truth about the Hadley/CRU data: "The global temperature rise calculated by the Met Office's HadCRUT record is at the lower end of likely warming."
And the falsehoods about the Russian Institute of Economic analysis are exposed
Everybody but the anti-science disinformers have known for a long time that the Hadley/CRU (Climatic Research Unit) temperature data UNDERestimates - not OVERestimates - the recent global temperature rise. I've repeatedly written about how this data excludes "the place on Earth that has been warming fastest" (see "Why are Hadley and CRU withholding vital climate data from the public?" and "What exactly is polar amplification and why does it matter?"). So has NASA's James Hansen (for years) among others.
The disinfomers - people like the Competitive Enterprise Institute – have been trumpeting yet more ass-backwards disinformation on this, spun from the Russian Institute of Economic Analysis (but debunked by Tim Lambert aka Deltoid and others). Now the Met Office has buried them with a new analysis, published Friday on their website:
New evidence confirms land warming record
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Global warming hike may be steeper
Global temperatures could rise substantially more because of increases in carbon dioxide in the atmosphere than previously thought, according to a new study by U.S. and Chinese scientists released Sunday.
The researchers used a long-term model for assessing climate change, confirming a similar British study released this month that said calculations for man-made global warming may be underestimated by between 30 and 50 percent.
The new study published online by Nature Geoscience focused on a period three to five million years ago-the most recent episode of sustained global warming with geography similar to today's, a Yale University statement said.
This was in order to look at the Earth's long-term sensitivity to climate fluctuation, including in changes to continental icesheets and vegetation cover on land.
More common estimates for climate change are based on relatively rapid feedback to increases in carbon dioxide, such as changes to sea ice and atmospheric water vapour.
Using sediment drilled from the ocean floor, the scientists' reconstruction of carbon dioxide concentrations found that "a relatively small rise in CO2 levels was associated with substantial global warming 4.5 million years ago."
They also found that the global temperature was between two and three degrees C (3.6 and 5.4 degrees F) higher than today even though carbon dioxide levels were similar to the current ones, the statement said.
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In must-see AGU (American Geophysical Union) video, Richard Alley explains "The Biggest Control Knob: Carbon Dioxide in Earth's Climate History"
I'd strongly recommended it to anybody who wants to understand why scientists are so certain that CO2 is such a big driver of our climate. It is for an audience of geophysicist types, but is probably the most understandable science lecture on the subject you are likely to watch.
Here's how Easterbrook summarizes it:
By way of introduction, he pointed out how many brains are in the room, and how much good we're all doing. Although he characterizes himself as not being an atmospheric scientist, except perhaps by default, but as he looks more and more at paleo-geology, it becomes clear how important CO2 is. He has found that CO2 makes a great organising principle for his class on the geology of climate change at Penn State, because CO2 keeps cropping up everywhere. So, he's going to take us through the history to demonstrate this. His central argument is that we have plenty of evidence now (some of it very new) that CO2 dominates all other factors, hence "the biggest control knob" (later in the talk he extended the metaphor by referring to other forcings as fine tuning knobs).
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That Tap Water Is Legal but May Be Unhealthy
The 35-year-old federal law regulating tap water is so out of date that the water Americans drink can pose what scientists say are serious health risks - and still be legal.
Only 91 contaminants are regulated by the Safe Drinking Water Act, yet more than 60,000 chemicals are used within the United States, according to Environmental Protection Agency estimates. Government and independent scientists have scrutinized thousands of those chemicals in recent decades, and identified hundreds associated with a risk of cancer and other diseases at small concentrations in drinking water, according to an analysis of government records by The New York Times.
But not one chemical has been added to the list of those regulated by the Safe Drinking Water Act since 2000.
Other recent studies have found that even some chemicals regulated by that law pose risks at much smaller concentrations than previously known.
However, many of the act's standards for those chemicals have not been updated since the 1980s, and some remain essentially unchanged since the law was passed in 1974.
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California, Nevada Lakes Warming Rapidly
Recent climate variability is causing a number of large lakes in California and Nevada to warm rapidly, according to a new NASA study.
Thermal infrared imagery from NASA's Moderate Resolution Imaging Spectroradiometer on board NASA's Terra and Aqua satellites and from the European Space Agency's series of Along-Track Scanning Radiometers were used to quantify changes in the thermal behavior of six large lakes in California and Nevada (Lake Tahoe, Mono Lake, Pyramid Lake, Walker Lake, Lake Almanor, and Clear Lake). The results found that between 1992 and 2008, the average nighttime temperatures of these lakes during the months of July, August and September increased at an average rate of 0.11 Kelvin (0.2 degrees Fahrenheit) per year. Results were validated against direct, ground measurements made at Lake Tahoe, on the California/Nevada border. Such rapid warming is expected to have a significant impact on lake ecosystems.
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Black Carbon Deposits on Himalayan Ice Threaten Earth's "Third Pole"
Black soot deposited on Tibetan glaciers has contributed significantly to the retreat of the world's largest non-polar ice masses, according to new research by scientists from NASA and the Chinese Academy of Sciences. Soot absorbs incoming solar radiation and can speed glacial melting when deposited on snow in sufficient quantities.
Temperatures on the Tibetan Plateau -- sometimes called Earth's "third pole" -- have warmed by 0.3oC (0.5oF) per decade over the past 30 years, about twice the rate of observed global temperature increases. New field research and ongoing quantitative modeling suggests that soot's warming influence on Tibetan glaciers could rival that of greenhouse gases.
"Tibet's glaciers are retreating at an alarming rate," said James Hansen, coauthor of the study and director of NASA's Goddard Institute for Space Studies (GISS) in New York City. "Black soot is probably responsible for as much as half of the glacial melt, and greenhouse gases are responsible for the rest."
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Major Groundwater Loss in California's Heartland
PASADENA, Calif. - New space observations reveal that since October 2003, the aquifers for California's primary agricultural region -- the Central Valley -- and its major mountain water source -- the Sierra Nevadas -- have lost nearly enough water combined to fill Lake Mead, America's largest reservoir. The findings, based on data from the NASA/German Aerospace Center Gravity Recovery and Climate Experiment (Grace), reflect California's extended drought and increased rates of groundwater being pumped for human uses, such as irrigation.
In research being presented this week at the American Geophysical Union meeting in San Francisco, scientists from NASA and the University of California, Irvine, detailed California's groundwater changes and outlined Grace-based research on other global aquifers. The twin Grace satellites monitor tiny month-to-month changes in Earth's gravity field primarily caused by the movement of water in Earth's land, ocean, ice and atmosphere reservoirs. Grace's ability to directly 'weigh' changes in water content provides new insights into how Earth's water cycle may be changing.
Combined, California's Sacramento and San Joaquin drainage basins have shed more than 30 cubic kilometers of water since late 2003, said professor Jay Famiglietti of the University of California, Irvine. A cubic kilometer is about 264.2 billion gallons, enough to fill 400,000 Olympic-size pools. The bulk of the loss occurred in California's agricultural Central Valley. The Central Valley receives its irrigation from a combination of groundwater pumped from wells and surface water diverted from elsewhere.
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Alarm as Gulf waters warm up
KUWAIT CITY // The seawater temperature in Kuwait Bay has been increasing at three times the global average rate since 1985, putting local fish stocks under pressure, a study by a researcher at the National Oceanography Centre in Southampton, England has found.
Thamer al Rashidi, 38, who carried out the four-year study for his doctorate in physical oceanography, said the temperature in Kuwait Bay is rising at an average rate of 0.62oC every decade. The intergovernmental Panel on Climate Change estimates the world average to be around one third of that figure.
Although the study focused on Kuwait Bay, the body of water to the north of Kuwait City, temperatures in the rest of the Gulf are also increasing at an alarming rate.
Mr al Rashidi said: "Temperature in the Arabian Gulf is increasing at 0.52oC per decade, and if you go closer to the shoreline, you will find it's higher."
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ICE MELTING FASTER EVERYWHERE
From the Arctic sea ice to the Antarctic interior and the mountainous peaks of Peru, Alaska, and Tibet, ice is melting at an alarming rate. The accelerating loss of ice sheets, sea ice, and glaciers is one of the most powerful and striking indicators of a warming climate.
The most notable ice loss in recent years has been the shrinking of sea ice in the Arctic Ocean. From the beginning of the satellite record in 1979 through 1996, ice area decreased at a steady rate of 3 percent per decade in response to rising temperature. In the following decade, ice area decreased by 11 percent, reaching a dramatic minimum in 2007. In September of that year, sea ice occupied only 3.6 million square kilometers, an area 27 percent smaller than the previous record low (in 2005) and 38 percent smaller than the 1979–2007 average. Summer sea ice coverage has increased slightly in the last two years, but it is still far below the long-term average.
Declines in ice thickness and volume are just as dramatic. The combination of these trends has led to a decrease in the amount of ice that persists in the Arctic through multiple seasons. Multiyear ice is more stable and less susceptible to break-up than the thin, short-lived seasonal ice that forms each winter. Between 1987 and 2007, the amount of ice at least five years old has plummeted from 57 to just 7 percent. Drastic changes in sea ice cover have led scientists from the University of Washington and the National Oceanic and Atmospheric Administration to predict that the summer of 2037 could see the first ice-free Arctic in a million years. Other scientists have predicted a largely ice-free summertime Arctic as early as 2015.
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7 Tipping Points That Could Transform Earth
When the Intergovernmental Panel on Climate Change issue its last report in 2007, environmental tipping points were a footnote. A troubling footnote, to be sure, but the science was relatively new and unsettled. Straightforward global warming was enough to worry about.
But when the IPCC meets in 2014, tipping points - or tipping elements, in academic vernacular - will get much more attention. Scientists still disagree about which planetary systems are extra-sensitive to climate shifts, but the possibility can't be ignored.
"The problem with tipping elements is that if any of them tips, it will be a real catastrophe. None of them are small," said Anders Levermann, a climate physicist at the Potsdam Institute for Climate Impact Research in Germany.
Levermann's article on potential disruptions of South Asia's monsoon cycles was featured in a series of tipping element research reviews, published December 8 in the Proceedings of the National Academy of Sciences.
Also discussed were ocean circulation, polar icecaps, Amazon rainforests, seafloor methane deposits and a west African dustbowl. Each is stressed by rising planetary temperatures. Some are less likely than others to tip; some might not be able to tip at all. Ambiguities, probabilities a limited grasp of Earth's complex systems are inherent to the science. But if any tip, it will be an epic disaster.
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Gauging Climate Change: How Fast Is the Earth Shifting?
There are many units by which to measure the impact of climate change: degrees of increasing temperature, feet of rising sea level, dollars needed to adapt to a warming world. But a group of scientists in California have put forth an intriguing new unit of measurement: kilometers per year.
Writing in a paper published Wednesday in Nature, scientists describe what they call the velocity of climate change, or more specifically, the speed of Earth's shifting climatic zones. As global temperature rises over the next century, the scientists argue, Earth's habitable climatic zones will start moving too, generally away from the Equator and toward the poles. That means many species of plants and animals will also have to move in order to survive. Whether or not they do will depend on several factors, but two of the most important are how fast a species can adjust its habitat range, and how quickly that range is moving out from under it.
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With warming trend, ice forming later in Adirondacks
ALBANY -- Ice is forming this week on picturesque Mirror Lake in the Adirondacks, weeks later than it once did as scientists continue to document a century-long warming trend.
"The weather is so variable, and the data sets are so few or incomplete, the ice cover is the one thing that stands out above everything else," said Curt Stager, professor of natural sciences at Paul Smith's College. "It's the most obvious, irrefutable sign of climate change in the North Country."
Stager and three other scientists co-authored a recent paper in the Adirondack Journal of Environmental Studies plotting regional climate changes since data collection began in the early 1900s. The data showed ice on Mirror Lake forming 14 or 15 days later and melting three or four days earlier than it did then, consistent with records from several other high-elevation Adirondack lakes.
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Study: Sea-level rise quickening along East Coast
Looking deep into the geologic past, researchers at the University of Pennsylvania have learned that along the Atlantic Coast, including New Jersey, sea level rose three times faster during the 20th century than it did during the previous 4,000 years.
At one location in North Carolina, they fixed the date of the rapid acceleration to between 1879 and 1915, after the Industrial Revolution had taken deep hold, lending credence to the connection between the rising temperatures that occurred then and rising sea levels.
"If that happened in the past, it gives you strong confidence that the predictions of increased sea-level rise in the 21st century are true," said lead researcher Benjamin P. Horton, a professor in Penn's sea-level research laboratory.
Scientists predict sea levels will rise as a result of global warming, "but by how much, when, and where it will have the most effect is unclear," Horton said.
"Lots of people are looking at the future," he said. "The problem is, they've been looking at the future without having the information to understand the past."
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