tagged w/ saturation
Excellent presentation by Peter Sinclair on the science of climate change and how it and we are now affecting the globe.
From the video:
"Fantastic TED style talk by Peter Sinclair on climate change at the International Conference on Sustainability, Transition and Culture Change: Vision - Action - Leadership organized by Local Future non-profit and directed by Aaron Wissner.
Sinclair's playlist of videos on climate change and addressing misconceptions are all available at:
Climate Denial Crock of the week is essential in understanding the motivations behind a movement bent on ideology and profit at all costs... even our only home.Excellent presentation by Peter Sinclair on the science of climate change and how it... more
Rising human carbon dioxide emissions may be affecting the brains and central nervous system of sea fishes with serious consequences for their survival, an international scientific team has found.
Carbon dioxide concentrations predicted to occur in the ocean by the end of this century will interfere with fishes' ability to hear, smell, turn and evade predators, says Professor Philip Munday of the ARC Centre of Excellence for Coral Reef Studies and James Cook University.
"For several years our team have been testing the performance of baby coral fishes in sea water containing higher levels of dissolved CO2 - and it is now pretty clear that they sustain significant disruption to their central nervous system, which is likely to impair their chances of survival," Prof. Munday says.
In their latest paper, published in the journal Nature Climate Change, Prof. Munday and colleagues report world-first evidence that high CO2 levels in sea water disrupts a key brain receptor in fish, causing marked changes in their behaviour and sensory ability.
"We've found that elevated CO2 in the oceans can directly interfere with fish neurotransmitter functions, which poses a direct and previously unknown threat to sea life," Prof. Munday says.
Prof. Munday and his colleagues began by studying how baby clown and damsel fishes performed alongside their predators in CO2-enriched water. They found that, while the predators were somewhat affected, the baby fish suffered much higher rates of attrition.
"Our early work showed that the sense of smell of baby fish was harmed by higher CO2 in the water - meaning they found it harder to locate a reef to settle on or detect the warning smell of a predator fish. But we suspected there was much more to it than the loss of ability to smell."
The team then examined whether fishes' sense of hearing - used to locate and home in on reefs at night, and avoid them during the day - was affected. "The answer is, yes it was. They were confused and no longer avoided reef sounds during the day. Being attracted to reefs during daylight would make them easy meat for predators."
Other work showed the fish also tended to lose their natural instinct to turn left or right - an important factor in schooling behaviour which also makes them more vulnerable, as lone fish are easily eaten by predators.
"All this led us to suspect it wasn't simply damage to their individual senses that was going on - but rather, that higher levels of carbon dioxide were affecting their whole central nervous system."
The team's latest research shows that high CO2 directly stimulates a receptor in the fish brain called GABA-A, leading to a reversal in its normal function and over-excitement of certain nerve signals.
While most animals with brains have GABA-A receptors, the team considers the effects of elevated CO2 are likely to be most felt by those living in water, as they have lower blood CO2 levels normally. The main impact is likely to be felt by some crustaceans and by most fishes, especially those which use a lot of oxygen.
Prof. Munday said that around 2.3 billion tonnes of human CO2 emissions dissolve into the world's oceans every year, causing changes in the chemical environment of the water in which fish and other species live.
"We've now established it isn't simply the acidification of the oceans that is causing disruption - as is the case with shellfish and plankton with chalky skeletons - but the actual dissolved CO2 itself is damaging the fishes' nervous systems."
More at the linkRising human carbon dioxide emissions may be affecting the brains and central nervous... more
The devastating string of tornadoes, droughts, wildfires and floods that hit the United States this spring marks 2011 as one of the most extreme years on record, according to a new federal analysis.
Just shy of the halfway mark, 2011 has seen eight $1-billion-plus disasters, with total damages from wild weather at more than $32 billion, according to the National Oceanic and Atmospheric Administration. Agency officials said that total could grow significantly, since they expect this year's North Atlantic hurricane season, which began June 1, will be an active one.
Overall, NOAA experts said extreme weather events have grown more frequent in the United States since 1980. Part of that shift is due to climate change, said Tom Karl, director of the agency's National Climatic Data Center.
"Extremes of precipitation are generally increasing because the planet is actually warming and more water is evaporating from the oceans," he said. "This extra water vapor in the atmosphere then enables rain and snow events to become more extensive and intense than they might otherwise be."
But for some kinds of extreme weather, teasing out a contribution from climate change is more difficult.
The second half of April brought a swarm of tornadoes that leveled parts of the Midwest, including the twister that killed 151 people in Joplin, Mo. So far, 2011 has seen the sixth-highest number of tornado deaths on record, prompting many people to wonder whether climate change has played a role. So far, scientists say there's no good evidence for or against a climate change influence on tornado behavior.
Meanwhile, computer models predict that droughts -- like those that have scorched large swaths of Texas, New Mexico and Arizona this year -- will become stronger and more frequent as climate change continues. But because patterns of drought vary widely from decade to decade, that makes it "very difficult and unlikely that we're going to be able to discern a human fingerprint, if there is one, on the drought record in the foreseeable future," Karl said.
cont.The devastating string of tornadoes, droughts, wildfires and floods that hit the... more
This winter's heavy snowfalls and other extreme storms could well be related to increased moisture in the air due to global climate change, a panel of scientists said on Tuesday.
This extra moisture is likely to bring on extraordinary flooding with the onset of spring in the Northern Hemisphere, as deep snowpack melts and expected heavy rains add to seasonal run-off, the scientists said in a telephone briefing.
As the planet warms up, more water from the oceans is evaporated into the atmosphere, said Todd Sanford, a climate scientist at the Union of Concerned Scientists. At the same time, because the atmosphere is warmer, it can hold onto more of the moisture that it takes in.
Intense storms are often the result when the atmosphere reaches its saturation point, Sanford said.
This year, a series of heavy storms over the U.S. Midwest to the Northeast have dropped up to 400 percent of average snows in some locations, said Jeff Masters, director of meteorology at Weather Underground.
The amount of water in that snowpack is among the highest on record, Masters said.
"If you were to take all that water and melt it, it would come out to more than 6 inches over large swaths of the area," Masters said. "If all that water gets unleashed in a hurry, in a sudden warming, and some heavy rains in the area, we could be looking at record flooding along the Upper Mississippi River and the Red River in North Dakota."
That tallies with projections by the U.S. National Weather Service, which last month said a large stretch of the north central United States is at risk of moderate to major flooding this spring.
Spring floods could be exacerbated by spring creep, a phenomenon where spring begins earlier than previously.
"We've documented in the mountains of the U.S. West that the spring runoff pulse now comes between one and three weeks earlier than it used to 60 years ago," Masters said. "And that's because of warmer temperatures tending to melt that snowpack earlier and earlier."
In the last century, global average temperatures have risen by 1.4 degrees Fahrenheit (.8 Celsius). Last year tied for the warmest in the modern record. One place this warmth showed up was in the Arctic, which is a major weather-maker for the Northern Hemisphere, according to Mark Serreze, director of the U.S. National Snow and Ice Data Center.
One driver of this winter's "crazy weather," Serreze said, is an atmospheric pattern known as the Arctic Oscillation, which has moved into what climate scientists call a negative phase.
This phase means there is high pressure over the Arctic and low pressure at mid-latitudes, which makes the Arctic zone relatively warm, but spills cold Arctic air southward to places like the U.S. Midwest and Northeast.
This negative Arctic Oscillation has been evident for two years in a row, the same two winters that have had extreme storms and heavy snowfalls.
It is possible, but not certain, that the negative Arctic Oscillation is linked to warming of the Arctic, which is in turn influenced by a decrease in sea ice cover throughout the region.
The only underlying explanation for these events is climate warming due to heightened greenhouse gas levels, Serreze said.This winter's heavy snowfalls and other extreme storms could well be related to... more