You’ve heard the good news on climate: after a century or more of continuous rise, U.S. CO2 emissions have finally begun to decline, due largely to changes in the energy sector. According to the Energy Information Agency (EIA), energy-related CO2 emissions in 2015 were 12% below their 2005 levels. The EIA says this is “because of the decreased use of coal and the increased use of natural gas for electricity generation.”
Is the EIA right in making natural gas the hero of the CO2 story? Hardly. Sure, coal-to-gas switching is real. But take a look at this graph showing the contributors to declining carbon emissions. Natural gas displacement of coal accounts for only about a third of the decrease in CO2 emissions.
By far the biggest driver of the declining emissions is energy efficiency. Americans…
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Is Climate Change an Urban Legend?
By Willis Eschenbach – Re-Blogged From http://www.WattsUpWithThat.com
So we were sitting around the fire at the fish camp on the Colombia a few days ago, and a man said “Did you hear about the scientific study into meat preservatives?” We admitted our ignorance, and he started in. The story was like this:
“A few years ago there was a study done by some University, I can’t remember which one, but it was a major one. What they did was to examine the corpses of people who had died in Siberia, and those that had died in Washington State. Now of course the people in Siberia weren’t eating meat preservatives during their lives, and the Washington people were eating them. And when they dug up the graves and looked at the bodies, guess what they found?”
Urban Legend: The Killer In The Back Seat SOURCE
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The natural gas leak from a storage facility in the hills above Los Angeles is shaping up as a major ecological disaster as it vents large amounts of methane, a potent greenhouse gas.
Sourced through Scoop.it from: www.washingtonpost.com
” […] A runaway natural gas leak from a storage facility in the hills above Los Angeles is shaping up as a significant ecological disaster, state officials and experts say, with more than 150 million pounds of methane pouring into the atmosphere so far and no immediate end in sight.
The rupture within a massive underground containment system — first detected more than two months ago — is venting gas at a rate of up to 110,000 pounds per hour, California officials confirm. The leak already has forced evacuations of nearby neighborhoods, and officials say pollutants released in the accident could have long-term consequences far beyond the region.
Newly obtained infrared video captures a plume of gas — invisible to the naked eye — spouting from a hilltop in the Aliso Canyon area above Burbank, like smoke billowing from a volcano. Besides being an explosive hazard, the methane being released is a powerful greenhouse gas, more potent than carbon dioxide in trapping heat in the lower atmosphere.
Scientists and environmental experts say the Aliso Canyon leak instantly became the biggest single source of methane emissions in all of California when it began two months ago. The impact of greenhouse gases released since then, measured over a 20-year time frame, is the equivalent of emissions from six coal-fired power plants or 7 million automobiles, environmentalists say. […]
The warming effects of aircraft vapor trails could be eased with fewer night flights, especially during winter, the report says.
Sourced through Scoop.it from: news.nationalgeographic.com
Nicola Stuber, first author of the study, to be published in tomorrow’s edition of the journal Nature, suggests that contrails’ overall impact on climate change is similar in scope to that of aircrafts’ carbon dioxide (CO2) emissions over a hundred-year period.
Aircraft are believed to be responsible for 2 to 3 percent of human CO2 emissions. Like other high, thin clouds, contrails reflect sunlight back into space and cool the planet.
However, they also trap energy in Earth’s atmosphere and boost the warming effect, the study says. […]
Contrails are artificial clouds that form around the tiny aerosol particles in airplane exhaust.
They appear only in moist, very cold (less than 40ºF/4ºC) air—usually at altitudes of 5 miles (8 kilometers) or higher.
Some contrails can last for a day or longer, though they gradually disperse and begin to resemble natural clouds.
Contrails Mystery Scientists disagree about the extent of contrails’ climate impact.
“The jury is out on the impact of contrails,” said Patrick Minnis, an atmospheric scientist at NASA’s Langley Research Center in Langley, Virginia.
David Travis, a climatologist at the University of Wisconsin-Whitewater, notes that some recent studies suggest that contrails have little impact on global climate change but have a greater regional warming impact.
“I prefer to think of contrails as a regional-scale climate problem, as they are most common in certain regions of the world, such as western Europe, eastern and central U.S., and parts of eastern Asia,” he said.
“This is due to a combination of dense air traffic in these areas and favorable atmospheric conditions to support contrail persistence once they form.”
Because of their locations and short life spans, contrails are a difficult study subject.
“The greatest impediment to understanding the contrail impacts on weather and climate is the poor state of knowledge of humidity in the upper troposphere [3.8 to 9.3 miles/6 to 15 kilometers in altitude],” NASA’s Minnis said.
“Until we can measure it properly and extensively, and model it and its interaction with cirrus clouds and contrails, we will continue to have large uncertainties about the effect of contrails.”
Winter is Contrail Season
At the high altitudes favored by commercial airlines, the air is much more humid in winter, so contrails are twice as likely in that season, study co-author Stuber said.
“We also found that flights between December and February contribute half of the annual mean climate warming, even though they account for less than a quarter of annual air traffic,” she said of her U.K.-based research.
Study leader Piers Forster, of England’s University of Leeds, suggests that contrails’ current impact on the atmosphere is likely to increase as air traffic grows. […]”<