Climate Articles
Human activity obliterates natural carbon cycle in Brazos River
Lyle Lovett gave the song new wings, but cowboys for generations have been lamenting lost love down by the "quick sandy" Brazos River.
Now a team of Texas geochemists have reported that damming and other human activities have obliterated something else: the natural carbon dioxide cycle in the state's longest river.
The study, published in the journal Biogeochemistry, is the first to document such overwhelming influence of human activity on carbon dioxide in a major river, according to Rice University.
Earth's rivers are thought to absorb and give off about one gigaton of carbon annually - a fraction of the 8.5 gigatons of carbon dioxide humans add to the atmosphere annually through the burning of fossil fuels, but a significant factor in any effort to describe how the atmosphere and biosphere systems exchange carbon dioxide.
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Hot river forces costly cutback for TVA
The Tennessee Valley Authority has lost nearly $50 million in power generation from its biggest nuclear plant because the Tennessee River in Alabama is too hot.
Unless the summer cools down, TVA could lose millions of dollars more, pushing up fuel costs and consumer electric bills even after seven consecutive monthly increases.
The Browns Ferry Nuclear Power Plant near Athens, Ala., has operated at only about half power for most of the past month and could remain at reduced power through September, TVA officials said. The three-reactor plant - TVA's biggest nuclear facility - has been the hardest hit of any of the nation's 104 nuclear plants by thermal concerns over river water, according to the Nuclear Energy Institute and TVA.
"All the radiant heat gets in the river when you have a summer as hot as this has been," TVA President Tom Kilgore said.
Today is expected to be the 40th day since July 8 that TVA has reduced power production at Browns Ferry because of hot water in the river. Last week, TVA violated its permit with the Alabama Department of Environmental Management when the river temperature topped 90 degrees.
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One of many ways climate disinformers mislead
In science, the only thing better than measurements made in the real world are multiple sets of measurements - all pointing to the same answer. That's what we find with climate change. The case for human caused global warming is based on many independent lines of evidence. Our understanding of climate comes from considering all this evidence. In contrast, global warming skepticism focuses on narrow pieces of the puzzle while neglecting the full picture.
What is the full picture? Humans are emitting around 30 billion tonnes of carbon dioxide into the air every year. This is leaving a distinct human fingerprint:
* From space and the Earth's surface, we see more heat being trapped by carbon dioxide
* Nights are warming faster than days
* The upper atmosphere is cooling while the lower atmosphere is warming
Signs of warming are found all over the globe (here are just a few):
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Disaster at the Top of the World
STANDING on the deck of this floating laboratory for Arctic science, which is part of Canada's Coast Guard fleet and one of the world's most powerful icebreakers, I can see vivid evidence of climate change. Channels through the Canadian Arctic archipelago that were choked with ice at this time of year two decades ago are now expanses of open water or vast patchworks of tiny islands of melting ice.
In 1994, the "Louie," as the crew calls the ship, and a United States Coast Guard icebreaker, the Polar Sea, smashed their way to the North Pole through thousands of miles of pack ice six- to nine-feet thick. "The sea conditions in the Arctic Ocean were rarely an issue for us in those days, because the thick continuous ice kept waves from forming," Marc Rothwell, the Louie's captain, told me. "Now, there's so much open water that we have to account for heavy swells that undulate through the sea ice. It's almost like a dream: the swells move in slow motion, like nothing I've seen elsewhere."
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A Mountain in the Stream
It is now possible to imagine the beginning of the end of a ruinous form of mining called "mountaintop removal." Local opposition is growing, and the Environmental Protection Agency is tightening rules and threatening to veto one of the largest projects ever proposed.
Enormous harm has already been inflicted on Appalachia's environment, most acutely in West Virginia. Mountaintop mining involves blasting the tops off mountains to expose subsurface coal seams. The coal is trucked away, but the debris is dumped over the side into the valleys, forests and streams below. As many as 2,000 miles of clear-running streams have been poisoned or buried in this fashion.
The dumping is a clear violation of the Clean Water Act. Regulators during the administration of President George W. Bush willfully looked the other way. The Obama administration is trying to turn things around. First it agreed to review about 80 existing permits. Then it raised the bar for new permits - tightening stream protections and promising a case-by-case analysis of new projects instead of the blanket approvals granted before.
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Limiting Ocean Acidification Under Global Change
ScienceDaily (Aug. 23, 2010) - Largely as a result of human activities such as the burning of fossil fuels for energy and land-use changes such deforestation, the concentration of carbon dioxide in the atmosphere is now higher that it has been at any time over the last 800,000 years. Most scientists believe this increase in atmospheric carbon dioxide to be an important cause of global warming.
Both the peak year of emissions and post-peak reduction rates influence how much ocean acidity increases by 2100. Changes in ocean pH over subsequent centuries will depend on how much the rate of carbon dioxide emissions can be reduced in the longer term.
Largely as a result of human activities such as the burning of fossil fuels for energy and land-use changes such deforestation, the concentration of carbon dioxide in the atmosphere is now higher that it has been at any time over the last 800,000 years. Most scientists believe this increase in atmospheric carbon dioxide to be an important cause of global warming.
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Geoengineering won't curb sea-level rise
Space mirrors and 'volcanic' blasts are not an easy fix for the rise in sea levels.
Unless they involve extreme measures, geoengineering approaches to offset the effects of human-driven climate changes won't do much to combat rising sea levels, an international team of scientists reports in the Proceedings of the National Academy of Sciences1.
That is because sea levels respond slowly to changes in Earth's temperature, says John Moore, a palaeoclimatologist at Beijing Normal University and lead author of the study.
"We've got this 150-year legacy of fossil-fuel [burning], land-use changes, et cetera," he says. "You can't just slam on the brakes instantaneously."
Moore and his team examined two proposed geoengineering schemes: mirrors orbiting in space to reduce incoming sunlight, and sulphates being shot into the upper atmosphere to create a bright, sunlight-reflecting haze - similar to the one produced naturally by the 1991 eruption of Mount Pinatubo in the Philippines. Either scheme could reduce incoming solar energy by about 1-4 watts per square metre, enough to offset the atmospheric warming caused by carbon dioxide build-up until at least 2070.
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If a Country Sinks Beneath the Sea, Is It Still a Country?
Rising ocean levels brought about by climate change have created a flood of unprecedented legal questions for small island nations and their neighbors.
Among them: If a country disappears, is it still a country? Does it keep its seat at the United Nations? Who controls its offshore mineral rights? Its shipping lanes? Its fish?
And if entire populations are forced to relocate -- as could be the case with citizens of the Maldives, Tuvalu, Kiribati and other small island states facing extinction -- what citizenship, if any, can those displaced people claim?
Until recently, such questions of sovereignty and human rights have been the domain of a scattered group of lawyers and academics. But now the Republic of the Marshall Islands -- a Micronesian nation of 29 low-lying coral atolls in the North Pacific -- is campaigning to stockpile a body of knowledge it hopes will turn international attention to vulnerable countries' plights.
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Local Officials: Lack of Oxygen Likely Killing Thousands of Fish in the Gulf
Preliminary tests show that a lack of oxygen in part of the Gulf of Mexico [1] caused thousands of fish to die, according to Louisiana authorities quoted by the Los Angeles Times.
The dead fish were found at the mouth of the Mississippi River, and state officials said the phenomenon-called a "fish kill" in some parts and a "jubilee" in others-was not directly related to the oil from BP's ruptured well, reported the New Orleans Times-Picayune.
"By our estimates there were thousands, and I'm talking about 5,000 to 15,000 dead fish [2]," St. Bernard Parish President Craig Taffaro said in a news release. "Different species were found dead including crabs, sting rays, eel, drum, speckled trout, red fish, you name it, included in that kill."
Dead zones, or areas of depleted oxygen, occur every year in the Gulf because of nutrient runoff from the Mississippi River stimulating oxygen-consuming bacteria. But as we've noted, scientists have predicted a larger than average dead zone [3] this year-raising questions of whether the low-oxygen conditions are being exacerbated by the oil spill.
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A 'Great Fizz' of Carbon Dioxide Was Produced at the End of the Last Ice Age
ScienceDaily (Aug. 26, 2010) - Imagine loosening the screw-top of a soda bottle and hearing the carbon dioxide begin to escape. Then imagine taking the cap off quickly, and seeing the beverage foam and fizz out of the bottle. Then, imagine the pressure equalizing and the beverage being ready to drink.
Rutgers marine scientist Elisabeth Sikes and her colleagues say that something very similar happened on a grand scale over a 1,000 year period after the end of the last ice age -- or glaciation, as scientists call it.
According to a paper published recently in the journal Nature, the last ice age featured a decrease in the amount of atmospheric carbon dioxide and an increase in the atmospheric carbon 14, the isotope that guides scientists in evaluating the rate of decay of everything from shells to trees.
In recent years, other researchers have suggested that some of that carbon dioxide flowed back into the northern hemisphere rather than being entirely released into the atmosphere in the southern hemisphere.
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Spurred by Warming Climate, Beetles Threaten Coffee Crops
Coffee production has long been vulnerable to drought or excess rains. But recently, a tiny insect that thrives in warmer temperatures - the coffee berry borer - has been spreading steadily, devastating coffee plants in Africa, Latin America, and around the world.
The highlands of southwestern Ethiopia should be ideal for growing coffee. After all, this is the region where coffee first originated hundreds of years ago. But although coffee remains Ethiopia's number one export, the nation's coffee farmers have been struggling.
The Arabica coffee grown in Ethiopia and Latin America is an especially climate-sensitive crop. It requires just the right amount of rain and an average annual temperature between 64 degrees Fahrenheit and 70 degrees Fahrenheit to prosper. As temperatures rise - Ethiopia's average low temperature has increased by about .66 degrees F every decade since 1951, according to the country's National Meteorological Agency - and rains become more variable, Ethiopian coffee farmers have suffered increasingly poor yields. Last year was especially bad, with exports dropping by 33 percent. Some have moved their coffee trees to higher elevations, while others have been forced to switch to livestock and more heat-tolerant crops, such as enset, a starchy root vegetable similar to the plantain.
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"Our planet is close to climate tipping points" and it is "clear that needed actions will happen only if the public, somehow, becomes forcefully involved."
Top climatologist launches new website with graphs and analysis
The nation's leading - and most scientifically prescient - climatologist has a new website, Updating the Climate Science: What Path is the Real World Following? It "will present updated graphs and discussion of key quantities that help provide understanding of how climate change is developing and how effective or ineffective global actions are in affecting climate forcings and future climate change."
He also has a new essay, "Activist", for "J. Henry Fair's upcoming book." As an aside I simply can't imagine why Fair titled his book, "The Day After Tomorrow," the dreadful, scientifically inaccurate 2004 climate movie that many folks, like director James Cameron, actually say set back the cause of informing the public about climate science and the dangers of unrestricted greenhouse gas emissions.
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A Climate Change Thought Experiment
It's unfair to call Bjørn Lomborg a climate skeptic even if he did write a book called The Skeptical Environmentalist. He believes in global warming, after all. He just thinks it's not our biggest problem right now, and in any case, we can simply adapt to it when it happens. Here he is a couple of days ago on the possibility of a large rise in sea level over the next century:
Here are the facts. A 20-foot rise in sea levels [...] would inundate about 16,000 square miles of coastline, where more than 400 million people currently live. That's a lot of people, to be sure, but hardly all of mankind. In fact, it amounts to less than 6% of the world's population - which is to say that 94% of the population would not be inundated. And most of those who do live in the flood areas would never even get their feet wet.
That's because the vast majority of those 400 million people reside within cities, where they could be protected relatively easily, as in Tokyo. As a result, only about 15 million people would have to be relocated. And that is over the course of a century. In all, according to Nicholls, Tol, and Vafeidis, the total cost of managing this "catastrophe" - if politicians do not dither and pursue smart, coordinated policies - would be about $600 billion a year, or less than 1% of global GDP.
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Peak Uncertainty, When Will We Run Out Of Fossil Fuels?
Once you know the size of the reserves (R) and production (P), you are just a devision away from the number of years those reserves would last if production wouldn't change. This is called the R/P-ratio. The R/P-ratios at the end of 2009 were:
* Oil: 46 years (depleted in 2055)
* Natural gas: 63 years (depleted in 2072)
* Coal: 119 years (depleted in 2128)
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'Dry Water' Could Make a Big Splash Commercially, Help Fight Global Warming
ScienceDaily (Aug. 26, 2010) - An unusual substance known as "dry water," which resembles powdered sugar, could provide a new way to absorb and store carbon dioxide, the major greenhouse gas that contributes to global warming, scientists reported at the 240th National Meeting of the American Chemical Society.
The powder shows bright promise for a number of other uses, they said. It may, for instance, be a greener, more energy-efficient way of jumpstarting the chemical reactions used to make hundreds of consumer products. Dry water also could provide a safer way to store and transport potentially harmful industrial materials.
"There's nothing else quite like it," said Ben Carter, Ph.D., researcher for study leader Professor Andrew Cooper. "Hopefully, we may see 'dry water' making waves in the future."
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El Niños Are Growing Stronger, NASA/NOAA Study Finds
ScienceDaily (Aug. 27, 2010) - A relatively new type of El Niño, which has its warmest waters in the central-equatorial Pacific Ocean, rather than in the eastern-equatorial Pacific, is becoming more common and progressively stronger, according to a new study by NASA and NOAA. The research may improve our understanding of the relationship between El Niños and climate change, and has potentially significant implications for long-term weather forecasting.
Lead author Tong Lee of NASA's Jet Propulsion Laboratory, Pasadena, Calif., and Michael McPhaden of NOAA's Pacific Marine Environmental Laboratory, Seattle, measured changes in El Niño intensity since 1982. They analyzed NOAA satellite observations of sea surface temperature, checked against and blended with directly-measured ocean temperature data. The strength of each El Niño was gauged by how much its sea surface temperatures deviated from the average. They found the intensity of El Niños in the central Pacific has nearly doubled, with the most intense event occurring in 2009-10.
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From Climate Science to Climate Activism - The Sequel
A couple of years ago, I posted a piece here describing the journey of Richard Somerville, a climatologist a the University of California, San Diego, from a tight focus on research to a role as an advocate for climate action.
It is a journey that comes with costs and compromises. When I taught a seminar at Bard College in 2007 on the role of communication in shaping environmental policy, I had the students split into defenders of two approaches taken by prominent climate scientists.
One group had to defend Susan Solomon, the much lauded atmospheric scientist who, while a co-leader of the 2007 science assessment by the Intergovernmental Panel on Climate Change, staunchly refused to provide her personal view of the implications of global warming research despite the prodding of reporters.
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Shrinking Atmospheric Layer Linked to Low Levels of Solar Radiation
ScienceDaily (Aug. 27, 2010) - Large changes in the sun's energy output may drive unexpectedly dramatic fluctuations in Earth's outer atmosphere.
Results of a new study link a recent, temporary shrinking of a high atmospheric layer with a sharp drop in the sun's ultraviolet radiation levels.
The research, led by scientists at the National Center for Atmospheric Research (NCAR) in Boulder, Colo., and the University of Colorado at Boulder (CU), indicates that the sun's magnetic cycle, which produces differing numbers of sunspots over an approximately 11-year cycle, may vary more than previously thought.
The results, published in the American Geophysical Union journal Geophysical Research Letters, are funded by NASA and by the National Science Foundation (NSF), NCAR's sponsor.
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