dinsdag 9 september 2014

Global Warming 4

From Pine Beetles to Disappearing Glaciers, NASA Scientists Tell of "Dramatic" Planetary Changes

Monday, 08 September 2014 10:31By Dahr JamailTruthout | News Report
Trees turning red in forests that have been attacked by the mountain pine beetle near a wildfire site in Montana, July 7, 2011. Some scientists are increasingly worried that as the warming accelerates, trees themselves could become climate-change victims on a massive scale. (Josh Haner/The New York Times)Trees turning red in forests that have been attacked by the mountain pine beetle near a wildfire site in Montana, July 7, 2011. Some scientists are increasingly worried that as the warming accelerates, trees themselves could become climate-change victims on a massive scale. (Josh Haner/The New York Times)Until very recently, popular thinking assumed that anthropogenic climate disruption (ACD) was in a "slow" period. However, last year, a study published in Geophysical Research Letters showed that the planet had experienced more overall warming in the 15 years leading up to March 2013 than it had in the 15 years before that. In case there was any doubt that the planet is warming more quickly than previously thought, a study publishedin the August 22, 2014 issue of Science has verified this.
Another study from July addressed how regional climate systems were synchronizing, after which "the researchers detected wild variability that amplified the changes and accelerated into an abrupt warming event of several degrees within a few decades." Shortly thereafter, yetanother study showed that rapid warming of the Atlantic waters, most likely due to ACD, has "turbocharged" the Pacific Equatorial trade winds. Whenever that phenomenon stops, it is highly likely we will witness very rapid changes across the globe, including a sudden acceleration of the average surface temperature of the planet.
The vast majority of the myriad studies generating our present data on ACD paint a dire picture of what our CO2 emissions, and now massive methane releases, have done to the climate of Earth.
Truthout recently spoke with several NASA-affiliated scientists about what they are seeing.
One of them, Dr. Phil Townsend, a professor of Forest and Wildlife Ecology who helps train astronauts in spotting ACD indicators as they look down from the International Space Station (ISS), noted that we must ready ourselves to confront "a planet that looks quite a bit different."
"The planet will survive," Townsend told Truthout, "But things we valued or were interested in preserving because we like them, like White Bark Pine Tree and Grizzly Bears, are things we don’t want to lose. But we have to be prepared for something that might look completely different and may not have things that we value."
"The Planet Is Changing a Lot."
Townsend, who specializes in the use of remote sensing (from satellites and the ISS) to identify how ecosystems respond to all manners of change, is particularly interested in the chemistry and physiology of ecosystems and how they work.
"I like to describe it as the heartbeat and lung capacity of ecosystems," he said. "The same things humans need to do that indicate the health of an ecosystem are important to vegetation as well."
According to Townsend, there are several major types of changes happening to Earth right now.
"At one level, there is large-scale land use change, and we can see this," he explained. "It's the most dramatic in places like the Amazon and other rainforest areas that were previously not easy to access but are now more accessible and provide a source for wood and other materials. These are very visible and have a dramatic impact on you when you see them."
NASA scientist Dr. William Stefanov is the associate ISS program scientist for earth observations, as well as the lead scientist with the Earth Science and Remote Sensing Unit at the Lyndon B. Johnson Space Center in Houston, Texas. He works with the international partners and instrument science/operation teams to coordinate collection, distribution and analysis of remotely sensed data from the ISS in response to catastrophic events such as volcanic eruptions, earthquakes and flooding, in addition to using remote sensing data to study ACD impacts, which is where Townsend gets some of his data.
"We have cameras taking very high resolution . . . visual imagery of the land surface, so you can look at that over time to observe things like changes to shorelines due to perhaps rising sea level, you could look at changes in vegetation cover resulting from droughts or wildfires," Stefanov told Truthout. "You could also look at changes to urban growth patterns, as that relates to changing local to regional climate around urban centers. Other sensors will look at atmospheric patterns, like circulation changing as temperature informs atmospheric interactions."

"Things we valued or were interested in preserving because we like them, like White Bark Pine Tree and Grizzly Bears, are things we don’t want to lose. But we have to be prepared for something that might look completely different and may not have things that we value."

The second main change Townsend is witnessing is the number of disturbances occurring on the planet. We often hear about average temperature changing a degree or two, but even these "small" changes in temperature are causing more extreme climates around the globe, which in turn have a dramatic impact on humans.
"The planet is changing a lot," Townsend said. "Less frequent but heavier rainstorms, more frequent and heavier drought. Some of these are natural cycles, but some are more exaggerated and occurring more frequently . . . what when we look from space is the level of disturbances that are occurring."
In addition to droughts and floods, other disturbances Townsend and the astronauts can see from space include fires, insect outbreaks and more direct human impacts like excessive logging.
But what Townsend is focusing on most now is insects.
"Mountain Pine Beetle damage to pine forests has extended way further to the north into Alberta and British Columbia than we've noted in historical times since people started keeping records 150 years ago," he said. "And now it's at higher elevations in the southern Rockies than it's ever been, and this is a consequence of not necessarily changes in the average temperatures but changes in the minimum temperatures."
Prior to the level of impacts from ACD we are seeing now, temperatures of negative 40° F in the higher elevations of the Rocky Mountains during winter were common. These low temperatures were enough to kill off 99 percent of the beetle larvae that were "over-wintering" at the higher elevations. "But we haven't had temperatures that have gotten that low in 25 or 30 years, and so still a lot of the larvae get killed off, but maybe it's only 90 percent of the larvae that get killed off," Townsend  said - and that seemingly small shift has major consequences.
Whereas previously less than 1 percent of the mountain pine beetle larvae survived winters, keeping them in check, now 10 percent survive. Over time, this is leading to dramatically large increases in their populations, augmented by the fact that now they can persist and expand into climate zones where they previously weren't able to live.
Townsend describes this change as "amazing." He added: "So if you look at the satellite imagery and look down at the planet, you see these huge areas, there are large parts of Colorado, Wyoming and Montana, just the extent of the mountain pine beetle, this really changes the ecosystem. The mountain pine beetle has always been there, but the changes of large areas much more rapidly than in the past. It used to be spread out in time and space, and now you just see these huge areas."
This means that forests can no longer hold snow through the season because so many trees have been defoliated, causing snow to melt faster and run off faster, leading to less water being available in the summer.
This also impacts the higher elevation forests, which are critical habitat for the Grizzly Bear.
Shockingly, mountain pine beetles have destroyed 10 times the amount of area, in order of magnitude, than fire, in any one year, according to Townsend - and the monetary damage they've caused is eight to 10 times greater than fires, because the area they are impacting is so vast.
Stefanov and his group are also monitoring desertification in certain areas of the globe, like the southwestern United States.
"Virtually every climate model predicts that the US southwest is going to become hotter and drier, with less precipitation in general," he said. "One could predict the southwest might see more desertification as well, and even more so in areas that do get relatively high amounts of precipitation - like the Sonoran desert is becoming even drier and with changes to the biota there and stresses on the water supply and power supplies for people living in those areas."
He is also seeing higher levels of deforestation due to direct human influence, as is Townsend.
"Indonesia, the Amazon, a lot of that is due to direct human influence," said Stefanov. "People clearing forest areas, changing land use for short-term agricultural gain instead of long term preservation of the forests there."

Shockingly, mountain pine beetles have destroyed 10 times the amount of area, in order of magnitude, than fire, in any one year

Stefanov is also teaching the astronauts to spot changes in vegetation cover or health, such as tree death caused by mountain pine beetles. "In the US you are seeing a lot of effects on pine forests from bark beetles, and some of this is related to the increasing temperatures making it more favorable for the bark beetles to attack, and stressing the trees at the same time, while decreasing their ability to combat the invading insects," he said. "Those are two other things that lead to more local scale deforestation."
Like Stefanov, another massive issue Townsend is watching are wildfires.
"Especially high latitude fires such as in the Arctic, appear to be much more frequent," he explained. "They are much warmer, they are burning off much of the organic soils that are up there, which is releasing carbon into the atmosphere. It is changing the system pretty dramatically and drying it out and burning it off."
A "No-Analog" Situation
As dramatic as the changes he's seeing from land use and the mountain pine beetle are, the change Townsend is perhaps most concerned about involves planetary vegetation, which takes a long time to respond to climatic changes. Remote-sensing imagery now allows scientists to view some of those changes, which can take forms that sometimes contradict each other: He notes there are "earlier springs, longer growing seasons in some places, but in other places an earlier fall, and it's drier and not enough water."
Townsend refers to this as "asynchrony": "That is, things that were previously synchronous and occurring at the same time, don't anymore. So an example would be an earlier spring, where there might be birds or insects or animals that are tied to when things green up, and if things are greening up, and if vegetation sources that birds or animals rely upon for food become available at a different time than they are used to, then this can have a big effect on animals and other things that we don't necessarily see."

"There's a reason why the IPCC [UN Intergovernmental Panel on Climate Change] keeps getting more and more adamant about what they are seeing."

It's these less obvious changes that concern Townsend, because a decade or three down the road we may be shocked at the dramatic changes stemming from these. He sees ecological shifts that are occurring slowly over time, and while visible in the imagery collected from space, worries that we are not paying enough attention to these changes.
Hence, we find ourselves in a position of not knowing what is coming next since we have altered the climate and physical landscape as dramatically as we have in such a short period of time.
"Now you put us in a situation which us sciency types call a 'no analog situation,' which is to say that we don't know necessarily what is next," he said.
It's the combination of such vast areas of the planet changing so rapidly due to direct human activity, coupled with major climatic changes that give Townsend pause.
"That means the environment, after a disturbance has occurred, for a new generation of plants to come in there may be completely different from what was there before," he said.
"So think of it. Trees get established over hundreds of years, then climate may change, but once they are established they can survive a whole range of conditions. But if conditions change all of the sudden, and at the same time you remove the ecosystems that have been there, the ecosystems that come back may in fact not at all look like the ecosystem that was there originally."
Townsend said the effects of climate change and the way they are compounding has really become obvious in the last 10 to 15 years.
"People call scientists alarmists but we are looking at this stuff every day and seeing the changes," he warned. "There's a reason why the IPCC [UN Intergovernmental Panel on Climate Change] keeps getting more and more adamant about what they are seeing, because it is getting more dramatic because of the compounding of all of these different things that are coming into play now." 
The Vanishing West Antarctic Ice Sheet
Robert Bindschadler, NASA emeritus scientist. (Photo: Robert Bindschadler)Robert Bindschadler, NASA emeritus scientist. (Photo: Robert Bindschadler)NASA emeritus scientist Robert Bindschadler, who worked for 35 years as a glaciologist at NASA Goddard Space Flight Center, has sounded the warning loud and clear about collapsing ice sheets and rising sea levels. In an interview with Truthout, Bindschadler warned that he expects to see a three- to four-meter sea level rise by 2200.
Like Townsend and Stefanov, Bindschadler used updated satellite data to track what was happening in the Antarctic.
"We were seeing changes on the time scale of a decade," he explained. "These ice streams could switch on and off, sometimes very suddenly. The time frame of change was growing shorter and shorter.  We had thought millennia to centuries, but now we're seeing it in decades, and then we started seeing changes of even a few percent of speed in just a year or two. So we were reeling from one season's discoveries to the next."
Bindschadler said that he and his scientific colleagues all began to watch what happened before on geologic time scales now occurring on human time scales.
"Everybody was starting to see this faster pace of change. Especially driven by the increase in greenhouse gases, CO2 really was driving the system faster," he said. "We were driving the system hard, and it was responding on observable time frames. We continued to see more dramatic changes happening in shorter time scales, and this was reflected in the series of IPCC reports."
According to Bindschadler, it would be "irresponsible" for the scientific community to give the public "false hope" that we won't see a one-meter sea level rise by 2100, and warned that we should plan for this, although he added that "It might even be worse."
He spent decades studying the West Antarctic Ice Sheet, the only marine-based ice sheet left on the planet.
"If we were to see the West Antarctic Ice Sheet go, we would expect to see dramatic retreat, thinning at the margins, production of large icebergs, initial stages of episodic retreats, that's what we think it would look like," he said about the potential collapse of this massive body of ice.
A large number of studies have corroborated exactly what Bindschadler said, the most recent and perhaps best known being that published in May, which showed that West Antarctic glaciers are in "irreversible" decline.
"So when you compare that list of characteristics with what we have observed, it's just a one-to-one match," Bindschadler said of the possibility of a collapsed West Antarctic Ice Sheet. "That's exactly what we see happening. So there is every reason to think that our view of how this irreversible retreat would manifest in the early stages, there is every reason to think that that is what is happening, because that is what we are observing."
When asked if he believed it was possible for the West Antarctic Ice Sheet to collapse in rapid fashion, his response was a blunt "Yes." And the consequences, by any measure, would be dramatic. If all the ice sheets and glaciers melted in Antarctica, the Arctic, and Greenland, there is enough ice in all of them to raise sea levels by an astounding 80 meters globally.
"Greenland itself has enough ice to raise sea levels five meters, and West Antarctica about the same size," Bindschadler added.
Stefanov and his group are also tracking the recession in some of the larger ice bodies on the planet.
"Glacier volume is one of the main things we're monitoring around the world, and we're seeing glaciers reducing in volume, for the most part they are receding, and the most common culprit is increasing temperatures in the regional areas that are causing the glaciers to lose volume," he said.
These observations link to other researcher's work on monitoring global sea level rise. Stefanov said of the increasing temperature: "Also global temperature - climate scientists also have been able to measure that, and we know that is increasing. There may be year-to-year fluctuations, where you may have an anomalously cold or hot year, but long-term trends are upwardly trending."
Stefanov noted that Arctic ice in particular has been decreasing in summer months.
"Previous years there was enough ice pack to cover that area throughout the summer, but now it regularly diminishes, and some climate scientists predict that soon there'll be open sea lanes," he said.  
 Overall, the prognosis of the general scientific community is that we must brace ourselves for more change, more extreme weather events and the likelihood of massive changes that used to occur in geologic time happening on a human time scale.
Stefanov has seen these trends occurring in tandem with the ever-growing expansion of the human footprint on Earth.
"Most of my career I've looked at urban areas, so I've seen a trend of general expansion of the human footprint over the planet, and that of course brings its attendant changes to local climate," he said. "So you have people becoming more prone to extreme heat events; you're seeing changes to biodiversity. When the human footprint expands, some species seem to be perfectly fine living in human-engineered environments, while others just can't take it so they move to different areas."
Yet, as the multiple onslaught of drought, wildfires, increasing temperatures and mountain pine beetles shows, there are less and less "different areas" for species to run.
Founded in late 2007 by philanthropist Sara Miller-McCune, Miller-McCune is a nonprofit print and online magazine harnessing hard data and breaking research to support journalism that focuses on finding solutions to social problems. Supported by a combination of grants and advertising, Miller-McCune rejects any overriding ideology, believing that the best answers can come from anywhere.

DAHR JAMAIL

Dahr Jamail, a Truthout staff reporter, is the author of The Will to Resist: Soldiers Who Refuse to Fight in Iraq and Afghanistan, (Haymarket Books, 2009), and Beyond the Green Zone: Dispatches From an Unembedded Journalist in Occupied Iraq, (Haymarket Books, 2007). Jamail reported from Iraq for more than a year, as well as from Lebanon, Syria, Jordan and Turkey over the last ten years, and has won the Martha Gellhorn Award for Investigative Journalism, among other awards.
His fourth book, The Mass Destruction of Iraq: Why It Is Happening, and Who Is Responsible, co-written withWilliam Rivers Pitt, is available now on Amazon. He lives and works in Washington state.

    Geen opmerkingen: