We Speak For Earth
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mohandasgandhi Mohandas Gandhi -
realcleverscience Real Clever Science -
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perscientiamlibertas A Matter of the Most Pleasant Fraternal Confidence
Recent Global Warming Slowed by Volcanoes
Global average temperatures have been rising in recent years, but not as much as they might have, thanks to a series of small-to-moderate-sized volcanic eruptions that have spewed sunlight-blocking particles high into the atmosphere. That’s the conclusion of a new study, which also finds that microscopic particles derived from industrial smokestacks have done little to cool the globe.
Between 2000 and 2010, the average atmospheric concentration of carbon dioxide — a planet-warming greenhouse gas — rose more than 5%, from about 370 parts per million to nearly 390 parts per million. If that uptick were the only factor driving climate change during the period, global average temperature would have risen about 0.2°C, says Ryan Neely III, an atmospheric scientist at the University of Colorado, Boulder. But a surge in the concentration of light-scattering particles in the stratosphere countered as much as 25% of that potential temperature increase, he notes.
According to satellite data, a measure of the light-scattering ability of the stratospheric particles, called aerosols, rose on average between 4% and 7% each year between 2000 and 2010. (The more incoming sunlight is scattered back into space, the stronger the cooling effect.) But researchers have strongly debated the source of those aerosols, Neely says. While many teams have suggested that the aerosols came from small-to-mid-sized volcanic eruptions, a few others have proposed that they originated in Asian smokestacks. Their rationale: Emissions of sulfur dioxide in India and China grew about 60% during the decade, and atmospheric convection associated with the region’s summer monsoon provides a way for watery droplets containing that gas to reach the stratosphere then diffuse around the world.
Former University of Michigan graduate student Katy Keller with a hand on eroded and melting permafrost near Toolik Lake, Alaska. The gully erosion seen here is a type of thermokarst failure, formed when ice-rich, permanently frozen soils are warmed and thawed. Image: George Kling
Ancient carbon trapped in Arctic permafrost is extremely sensitive to sunlight and, if exposed to the surface when long-frozen soils melt and collapse, can release climate-warming carbon dioxide gas into the atmosphere much faster than previously thought.
University of Michigan ecologist and aquatic biogeochemist George Kling and his colleagues studied places in Arctic Alaska where permafrost is melting and is causing the overlying land surface to collapse, forming erosional holes and landslides and exposing long-buried soils to sunlight.
They found that sunlight increases bacterial conversion of exposed soil carbon into carbon dioxide gas by at least 40 percent compared to carbon that remains in the dark. The team, led by Rose Cory of the University of North Carolina, reported its findings in an article to be published online Feb. 11 in the Proceedings of the National Academy of Sciences.
“Until now, we didn’t really know how reactive this ancient permafrost carbon would be — whether it would be converted into heat-trapping gases quickly or not,” said Kling, a professor in the U-M Department of Ecology and Evolutionary Biology. EEB graduate student Jason Dobkowski is a co-author of the paper.
“What we can say now is that regardless of how fast the thawing of the Arctic permafrost occurs, the conversion of this soil carbon to carbon dioxide and its release into the atmosphere will be faster than we previously thought,” Kling said. “That means permafrost carbon is potentially a huge factor that will help determine how fast the Earth warms.”
Tremendous stores of organic carbon have been frozen in Arctic permafrost soils for thousands of years. If thawed and released as carbon dioxide gas, this vast carbon repository has the potential to double the amount of the heat-trapping greenhouse gas in the atmosphere on a timescale similar to humanity’s inputs of carbon dioxide due to the burning of fossil fuels.
That creates the potential for a positive feedback: As the Earth warms due to the human-caused release of heat-trapping gases into the atmosphere, frozen Arctic soils also warm, thaw and release more carbon dioxide. The added carbon dioxide accelerates Earth’s warming, which further accelerates the thawing of Arctic soils and the release of even more carbon dioxide.
Recent climate change has increased soil temperatures in the Arctic and has thawed large areas of permafrost. Just how much permafrost will thaw in the future and how fast the carbon dioxide will be released is a topic of heated debate among climate scientists.
In lakes and streams, fish and insects can help protect aquatic plants that gobble up greenhouse gas
Climate scientists note that Earth will suffer excessive warming if levels of carbon dioxide and other greenhouse gases in the atmosphere get much higher. That’s why scientists have been looking for ways to encourage living organisms to act like a sponge, mopping up and storing much of that carbon dioxide. These carbon-storing species include trees, grasses and algae.
The Microbial Communities of the Future
The world, it turns out, is getting warmer. The extent and precise contours of climate change may never be forecastable, but many scientists are working to test the repercussions of a warmer atmosphere, in order to both inform policy discussions and instigate difficult discussions about adaptation strategies.
Nicholas Bouskill, an ecologist at the University of California at Berkeley, is one such scientist. Through a carefully designed study of jungle floor patches in Puerto Rico, Bouskill and his team are hoping to determine how the microbial make-up of soil changes in response to repeated periods of dryness. “These locations are likely to experience changes in the magnitude of rainfall, with increased drought and longer dry periods,” he writes in a recent edition of the ISME Journal.
It wasn’t necessarily clear how a drier environment would impact the microbial community since soil moisture is a double edged sword: Too much of it, and the diffusion of important gases in and out of the soil is limited; too little, and nutrients might not reach the microbes in sufficient quantities. So how, and how quickly, might soil-based microbial communities change in response to less water? Bouskill sought answers by tracking diversity shifts in plots of soil cut off from rain throughfall for the first time and those experiencing a second artificial drought.
Black Carbon is No. 2 Man-Made Global Warming Culprit
Black carbon is the second largest man-made contributor to climate change and its influence on the environment has been greatly underestimated, according to the first quantitative and comprehensive analysis of this issue.
Key findings of a new study include:
Black carbon has a much greater (twice the direct) climate impact than reported in previous assessments.
Black carbon ranks “as the second most important individual climate-warming agent after carbon dioxide.”
Cleaning up diesel engines and some wood and coal combustion could slow the warming immediately.
Read more: http://www.laboratoryequipment.com/news/2013/01/black-carbon-no-2-man-made-global-warming-culprit
(via scinerds)
Global warming has caused monthly records for heat to increase fivefold in frequency, according to a study by scientists in Germany and Spain, published on Monday.
In parts of Europe, Africa and southern Asia, the frequency of months with record-breaking heat has surged tenfold, it said.
The evidence comes from an analysis of 131 years of monthly temperature data, monitored at 12,000 points around the world, which are stored in a NASA database.
If man-made warming is stripped out of the equation, 80 percent of the records for hottest-ever months would not have occurred, it said.
“The last decade brought unprecedented heatwaves, for instance in the US in 2012, in Russia in 2010, in Australia in 2009 and in Europe in 2003,” said Dim Coumou of the Potsdam Institute for Climate Impact Research near Berlin.
On current trends for global warming, the number of new monthly heat records will be 12 times higher in 30 years than today, the researchers said.
“This doesn’t mean there will be 12 times more hot summers in Europe than today—it actually is worse,” Coumou said in a press release issued by PIK.
“To count as new records, they actually have to beat heat records set in the 2020s and 2030s, which will already be hotter than anything we have experienced to date.”
The study, which was co-authored by scientists at the Complutense University of Madrid, appears in the journal Climatic Change.
(c) 2013 AFP
(via scinerds)
Nina Berman: “This image is part of a project I’ve been doing on shale-gas drilling and fracking. The picture shows contaminated water from a kitchen faucet in Bradford County, Pennsylvania. The water is discolored and is bubbling methane. It’s undrinkable. Many people in shale-gas country have experienced contaminated drinking water following drilling and fracking operations. This so-called clean energy, billed by energy companies as an environmentally sound solution to heat trapping fossil fuels, is actually very dirty to obtain and transport. I like the purple nail polish and that the cup is plastic. In my mind, these elements speak to the connection between polluting energy and our own lifestyles, which are enabled through petroleum based products.”
Click-through for a slideshow looking at photographers and other visual artists who are challenging viewers to consider the dangers of inaction by capturing the effects of extreme weather and a warming world: http://nyr.kr/UCR7Jh
Harvard Scientist Proposes a Way to Refreeze the Arctic to Combat Possible Global Warming Disaster
The amount of ice in the Arctic Ocean shrunk to an all time low in September, with the area covered now only half of what it was in the 1980s. This alarming development along with the global community’s inability to come to a consensus about cutting CO2 emissions has led Harvard professor of applied physics David Keith to look at a technological solution to reversing the warming of the Arctic. In a paper published in Nature Climate Change and an affiliated study in the Environmental Research Letters, Keith proposes a way to refreeze the Arctic through geoengineering.
Injecting reflective particles into the high atmosphere could reduce the amount of sunlight reaching the Earth’s surface, counteracting the greenhouse gas effect. High CO2 levels would continue to trap heat in the atmosphere, but with less energy coming in, temperatures on the surface would go down. Keith suggests using the method for a regional correction to restore the ice cover in the Arctic. In his paper, he claims that “with an average solar reduction of only 0.5%, it is possible to recover pre-industrial sea ice extent.” A separate paper shows that this could all be done with a few modified Gulfstream jets and is estimated to cost around $8 billion, which is about the price of a installing a major oil pipeline.
But large-scale geoengineering like what Keith is suggesting is banned by the United Nations Convention on Biological Diversity because it could result in disastrous unintended consequences. Even Keith acknowledges that manually refreezing the arctic is not the right way to solve the larger problem of global warming. He thinks that this level of geoengineering would only be appropriate to consider in states of emergency such as a sudden collapse of ice sheets or a killing drought. But first, we need to cut our greenhouse gas emissions and he warns that “if we do this and we do not cut emissions, we just walk further and further off the cliff, like Wile E. Coyote.”
(via ikenbot)
Mars Curiosity & James Cameron: Largest Earth Science Meeting Set to Begin
Thousands of Earth scientists are descending on San Francisco this week for the annual meeting of the American Geophysical Union, the largest geosciences meeting of the year, where new findings on topics ranging from Mars to volcanoes to global warming will be presented.
Advance press releases for the 2012 AGU meeting, held at the Moscone Center, have touted findings in numerous areas, including climate change and Martian geology, and include briefings from some big-name scientists like Mars rover principal investigator, Steve Squyres, and Jane Lubchenco, the administrator of the National Oceanic and Atmospheric Administration.
Another big name that will be present at the meeting is James Cameron, who will be talking about his deep-sea dive to the bottom of the Mariana Trench, the deepest spot on Earth, last year, and what he saw while he was down there.A briefing on the latest results from the Mars Curiosity rover mission that will be conducted at the meeting has been the subject of rampant speculation in the press, and NASA has tried to manage expectations, saying that the findings aren’t earth shattering.
Scientists will be presenting findings in hundreds of talks and posters throughing the duration of the meeting, which runs from Monday, Dec. 3, through Friday, Dec. 7. Press conferences from the meeting will be webcast live — you can see a full schedule and watch them here. You can also follow along with news from the meeting by checking out the hashtag #AGU12.
According to an exhaustive review by Prof. James Lawrence Powell, only 0.17 percent of thousands of peer-reviewed papers question global warming or whether rising emissions are the cause. Yup.
