Category Archives: CLIMATE CHANGE

Global warming 'confirmed' by independent study

BBC News – Global warming ‘confirmed’ by independent study.

The Earth’s surface really is getting warmer, a new analysis by a US scientific group set up in the wake of the “Climategate” affair has concluded.

The Berkeley Earth Project has used new methods and some new data, but finds the same warming trend seen by groups such as the UK Met Office and Nasa.

The project received funds from sources that back organisations lobbying against action on climate change.

“Climategate”, in 2009, involved claims global warming had been exaggerated.

Emails of University of East Anglia (UEA) climate scientists were hacked, posted online and used by critics to allege manipulation of climate change data.

Fresh start

The Berkeley group says it has also found evidence that changing sea temperatures in the north Atlantic may be a major reason why the Earth’s average temperature varies globally from year to year.

Saul Perlmutter The group includes physicist Saul Perlmutter, a Nobel Prize winner this year

The project was established by University of California physics professor Richard Muller, who was concerned by claims that established teams of climate researchers had not been entirely open with their data.

He gathered a team of 10 scientists, mostly physicists, including such luminaries as Saul Perlmutter, winner of this year’s Nobel Physics Prize for research showing the Universe’s expansion is accelerating.

Funding came from a number of sources, including charitable foundations maintained by the Koch brothers, the billionaire US industrialists, who have also donated large sums to organisations lobbying against acceptance of man-made global warming.

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Our biggest surprise was that the new results agreed so closely with the warming values published previously”

Richard Muller Berkeley group founder

“I was deeply concerned that the group [at UEA] had concealed discordant data,” Prof Muller told BBC News.

“Science is best done when the problems with the analysis are candidly shared.”

The group’s work also examined claims from “sceptical” bloggers that temperature data from weather stations did not show a true global warming trend.

The claim was that many stations have registered warming because they are located in or near cities, and those cities have been growing – the urban heat island effect.

The Berkeley group found about 40,000 weather stations around the world whose output has been recorded and stored in digital form.

It developed a new way of analysing the data to plot the global temperature trend over land since 1800.

What came out was a graph remarkably similar to those produced by the world’s three most important and established groups, whose work had been decried as unreliable and shoddy in climate sceptic circles.

graph The Berkeley group’s record of global land temperature mirrors existing ones closely

Two of those three records are maintained in the US, by the National Oceanic and Atmospheric Administration (Noaa) and National Aeronautics and Space Administration (Nasa).

The third is a collaboration between the UK Met Office and UEA’s Climatic Research Unit (CRU), from which the e-mails that formed the basis of the “Climategate” furore were hacked two years ago.

“Our biggest surprise was that the new results agreed so closely with the warming values published previously by other teams in the US and the UK,” said Prof Muller.

“This confirms that these studies were done carefully and that potential biases identified by climate change sceptics did not seriously affect their conclusions.”

Since the 1950s, the average temperature over land has increased by 1C, the group found.

They also report that although the urban heat island effect is real – which is well-established – it is not behind the warming registered by the majority of weather stations around the world.

They also showed that in the US, weather stations rated as “high quality” by Noaa showed the same warming trend as those rated as “low quality”.

‘Time for apology’

Prof Phil Jones, the CRU scientist who came in for the most personal criticism during “Climategate”, was cautious about interpreting the Berkeley results because they have not been published in a peer-reviewed journal.

“I look forward to reading the finalised paper once it has been reviewed and published,” he said.

Professor Phil Jones The findings so far provide validation for Phil Jones, targeted during the “Climategate” affair

“These initial findings are very encouraging, and echo our own results and our conclusion that the impact of urban heat islands on the overall global temperature is minimal.”

The Berkeley team has chosen to release the findings initially on its own website.

They are asking for comments and feedback before preparing the manuscripts for formal scientific publication.

In part, this counters the accusation made during “Climategate” that climate scientists formed a tight clique who peer-reviewed each other’s papers and made sure their own global warming narrative was the only one making it into print.

But for Richard Muller, this free circulation also marks a return to how science should be done.

“That is the way I practised science for decades; it was the way everyone practised it until some magazines – particularly Science and Nature – forbade it,” he said.

“That was not a good change, and still many fields such as string theory practice the traditional method wholeheartedly.”

This open “wiki” method of review is regularly employed in physics, the home field for seven of the 10 Berkeley team.

Bob Ward, policy and communications director for the Grantham Research Institute for Climate Change and the Environment in London, said the warming of the Earth’s surface was unequivocal.

“So-called ‘sceptics’ should now drop their thoroughly discredited claims that the increase in global average temperature could be attributed to the impact of growing cities,” he said.

“More broadly, this study also proves once again how false it was for ‘sceptics’ to allege that the e-mails hacked from UEA proved that the CRU land temperature record had been doctored.

“It is now time for an apology from all those, including US presidential hopeful Rick Perry, who have made false claims that the evidence for global warming has been faked by climate scientists.”

Ocean currents

The Berkeley group does depart from the “orthodox” picture of climate science in its depiction of short-term variability in the global temperature.

The El Nino Southern Oscillation (ENSO) is generally thought to be the main reason for inter-annual warming or cooling.

But by the Berkeley team’s analysis, the global temperature correlates more closely with the state of the Atlantic Multidecadal Oscillation (AMO) index – a measure of sea surface temperature in the north Atlantic.

There are theories suggesting that the AMO index is in turn driven by fluctuations in the north Atlantic current commonly called the Gulf Stream.

The team suggests it is worth investigating whether the long-term AMO cycles, which are thought to last 65-70 years, may play a part in the temperature rise, fall and rise again seen during the 20th Century.

But they emphasise that anthropogenic global warming (AGW) driven by greenhouse gas emissions is very much in their picture.

“Had we found no global warming, then that would have ruled out AGW,” said Prof Muller.

“Had we found half as much, it would have suggested that prior estimates [of AGW] were too large; if we had found more warming, it would have raised the question of whether prior estimates were too low.

“But we didn’t; we found that the prior rise was confirmed. That means that we do not directly affect prior estimates.”

The team next plans to look at ocean temperatures, in order to construct a truly global dataset.

Fires in Queensland, Australia

Fires in Queensland, Australia : Natural Hazards.

Fires in Queensland, Australia

acquired September 26, 2011 download large image (4 MB, JPEG)
acquired September 26, 2011 download Google Earth file (KMZ)

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite detected several fires burning in southeast Queensland on September 26, 2011. The fires are outlined in red.

The fire season in Queensland, Australia runs through the dry winter and spring. The Queensland government declared a fire danger period from September 4, 2011, to January 2, 2012, when fires are allowed by permit only. The fires shown in this image likely include both deliberately set fires and natural wildfires.

Many of Australia’s ecosystems require fire to stimulate growth and regenerate some plant species. As a result, the landscape is extremely prone to fire and burns easily.

  1. References

  2. CSIRO. (2008, February 14). Bushfire in Australia. Accessed September 26, 2011.
  3. CSIRO. (2008, April 30).The months of a fire season. Accessed September 26, 2011.
  4. Queensland Fire and Rescue Service. (2011, September). Fire danger period declared. Accessed September 26, 2011.

NASA image courtesy the MODIS Rapid Response Team at NASA GSFC. Caption by Holli Riebeek.

Instrument: 
Aqua – MODIS

New Research Casts Doubt on Doomsday Water Shortage Predictions

New Research Casts Doubt on Doomsday Water Shortage Predictions: Scientific American.

MELTDOWN: The melting of mountain glaciers around the world may not contribute as much to water supplies as thought, new research argues. Image: Abhishekjoshi/Flickr

From the Andes to the Himalayas, scientists are starting to question exactly how much glaciers contribute to river water used downstream for drinking and irrigation. The answers could turn the conventional wisdom about glacier melt on its head.

A growing number of studies based on satellite data and stream chemistry analyses have found that far less surface water comes from glacier melt than previously assumed. In Peru’s Rio Santa, which drains the Cordilleras Blanca mountain range, glacier contribution appears to be between 10 and 20 percent. In the eastern Himalayas, it is less than 5 percent.

“If anything, that’s probably fairly large,” said Richard Armstrong, a senior research scientist at the Boulder, Colo.-based Cooperative Institute for Research in Environmental Sciences (CIRES), who studies melt impact in the Himalayas.

“Most of the people downstream, they get the water from the monsoon,” Armstrong said. “It doesn’t take away from the importance [of glacier melt], but we need to get the science right for future planning and water resource assessments.”

The Himalayan glaciers feed into Asia’s biggest rivers: the Indus, the Ganges and the Brahmaputra in India, Pakistan and Bangladesh, and the Yellow and Yangtze rivers in China. Early studies pegged the amount of meltwater in these river basins as high as 60 or 70 percent. But reliable data on how much water the glaciers release or where that water goes have been difficult to develop. Satellite images can’t provide such regular hydrometeorological observations, and expeditions take significant time, money and physical exertion.

New methods, though, are refining the ability to study this and other remote glacial mountain ranges. Increasingly, scientists are finding that the numbers vary depending on the river, and even in different parts of the same river.

Creeping hyperbole
“There has been a lot of misinformation and confusion about it,” said Peter Gleick?, co-director of the California-based Pacific Institute for Studies in Development, Environment and Security. “About 1.3 billion people live in the watersheds that get some glacier runoff, but not all of those people depend only on the water from those watersheds, and not all the water in those watersheds comes from glaciers. Most of it comes from rainwater,” he said.

A key step forward came last year when scientists at Utrecht University in the Netherlands, using remote sensing equipment, found that snow and glacier melt is extremely important to the Indus and Brahmaputra basins, but less critical to others. In the Indus, they found, the meltwater contribution is 151 percent compared to the total runoff generated at low elevations. It makes up about 27 percent of the Brahmaputra — but only between 8 and 10 percent for the Ganges, Yangtze and Yellow rivers. Rainfall makes up the rest.

That in itself is significant, and could reduce food security for 4.5 percent of the population in an already-struggling region. Yet, scientists complain, data are often inaccurately incorporated in dire predictions of Himalayan glacial melt impacts.

“Hyperbole has a way of creeping in here,” said Bryan Mark, an assistant professor of geography at Ohio State University and a researcher at the Byrd Polar Research Center.

Mark, who focuses on the Andes region, developed a method of determining how much of a community’s water supply is glacier-fed by analyzing the hydrogen and oxygen isotopes in water samples. He recently took that experience to Nepal, where he collected water samples from the Himalayan glacier-fed Kosi River? as part of an expedition led by the Mountain Institute.

Based on his experience in the Rio Santa — where it was once assumed that 80 percent of water in the basin came from glacier melt — Mark said he expects to find that the impact of monsoon water is greatly underestimated in the Himalayas.

Jeff La Frenierre, a graduate student at Ohio State University, is studying Ecuador’s Chimborazo glacier, which forms the headwaters of three different watershed systems, serving as a water source for thousands of people. About 35 percent of the glacier coverage has disappeared since the 1970s.

La Frenierre first came to Ecuador as part of Engineers Without Borders to help build a water system, and soon started to ask what changes in the mountain’s glacier coverage would mean for the irrigation and drinking needs of the 200,000 people living downstream. Working with Mark and analyzing water streams, he said, is upending many of his assumptions.

Doomsday descriptions don’t fit
“The easy hypothesis is that it’s going to be a disaster here. I don’t know if that’s the case,” La Frenierre said. He agreed that overstatements about the impacts are rampant in the Himalayas as well, saying, “The idea that 1.4 billion people are going to be without water when the glaciers melt is just not the case. It’s a local problem; it’s a local question. There are places that are going to be more impacted than other places.”

Those aren’t messages that environmental activists will likely find easy to hear. Armstrong recalled giving a presentation in Kathmandu on his early findings to a less-than-appreciative audience.

“I didn’t agree with the doomsday predictions, and I didn’t have anything that was anywhere near spectacular,” Armstrong said. But, he added, “At the same time, it’s just basic Earth science, and we want to do a better job than we have been.”

The more modest numbers, they and other scientists stressed, don’t mean that glacier melt is unimportant to river basins. Rather, they said, they mean that the understanding of water systems throughout the Himalayan region must improve and water management decisions will need to be made at very local levels.

“We need to know at least where the water comes from,” Armstrong said. “How can we project into the future if we don’t know where the water comes from now?”

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500

Skeptical Research Effort Confirms Global Warming, Again

Skeptical Research Effort Confirms Global Warming, Again: Scientific American.

 

The Earth’s surface is warming, after all, says a team of researchers who sought to investigate claims that flawed data and methods had skewed existing analyses of global temperature trends.

The work by the Berkeley Earth Project shows that, on average, global land surface temperatures have risen about 1 degree Celsius since the mid-1950s — on par with the warming trend described by research groups at the National Oceanic and Atmospheric Administration, NASA and the U.K. Meteorological Office.

The Berkeley effort’s leader, astrophysicist Richard Muller, said his team had taken climate skeptics’ criticisms of existing research into account when they began to examine global temperature data going back to 1800.

But in the end, the factors singled out by skeptics — including some poorly sited temperature-monitoring stations — did not have much bearing on his group’s results.

“When we began this, I didn’t know whether we would see more warming than people had previously seen, or less. I knew that some skeptics had raised legitimate issues that needed further study,” said Muller, a professor at the University of California, Berkeley. “We’ve done that study now, and I think I’m surprised that the results agree with previous groups.”

The Berkeley group published four papers describing its work, its data and the programs it used to analyze those data yesterday on its website, berkeleyearth.org. The papers have not been peer-reviewed, but Muller’s team has submitted them for publication in scientific journals.

Several climate scientists said they weren’t surprised that the Berkeley group’s findings confirmed that the Earth is warming, something they said is supported by multiple lines of evidence — not just the instrumental temperature records examined by Muller.

Skeptics’ complaints don’t check out
Asked whether the Berkeley Earth findings were newsworthy, NASA climatologist Gavin Schmidt had a simple answer: “No.” But Schmidt said he thought the method Muller’s team devised for analyzing temperature data “does seem to be interesting,” though he cautioned that it had not been peer-reviewed.

Similarly, Kevin Trenberth, a senior scientist at the National Center for Atmospheric Research, said the Berkeley findings “need some good reviews.”

“It is interesting in many respects,” he said. “A good aspect is the sophisticated use of statistics. A bad aspect is the overuse of statistics and not enough common sense and basic physics.”

Peter Thorne, a climate scientist at the North Carolina-based Cooperative Institute for Climate and Satellites, called the Berkeley Earth analysis “certainly useful, though … not particularly novel.”

Having multiple research groups examine temperature records, each with its own method, helps reduce uncertainty in scientists’ estimate of ongoing warming, Thorne said. “I wish there were another 10 groups looking at the problem independently,” he added.

Meanwhile, Muller said he hopes his results will convince people who doubt whether the Earth is warming that it is indeed happening.

“We can’t win over the deniers,” he said. “There are people on both sides who grossly exaggerate. But in between, there are a substantial number of properly skeptical people. I believe that work we’re doing is the sort of work they’re looking for.”

It’s a case Muller makes today in a Wall Street Journal op-ed. “Global warming is real. Perhaps our results will help cool this portion of the climate debate,” he writes.

But reaction to the Berkeley Earth project has been mixed.

Before the group released its first set of findings last spring, liberal blogger Joe Romm of the Center for American Progress questioned the Berkeley group’s motives, noting that it had received funding from the Charles G. Koch Charitable Foundation, which has supported efforts opposing mainstream climate change science.

Warming could exceed safe levels in this lifetime

NewsDaily: Warming could exceed safe levels in this lifetime.

By Nina ChestneyPosted 2011/10/23 at 1:03 pm EDT

LONDON, Oct. 23, 2011 (Reuters) — Global temperature rise could exceed “safe” levels of two degrees Celsius in some parts of the world in many of our lifetimes if greenhouse gas emissions continue to increase, two research papers published in the journal Nature warned.

A general view shows the Iztaccihuatl volcano in the city of Puebla, 100 km (62 miles) east of Mexico City, in this April 24, 2010 file photo. REUTERS/Stringer/Instituto de Geofisica Universidad Nacional Autonoma de Mexico/Files

“Certain levels of climate change are very likely within the lifetimes of many people living now … unless emissions of greenhouse gases are substantially reduced in the coming decades,” said a study on Sunday by academics at the English universities of Reading and Oxford, the UK’s Met Office Hadley Center and the Victoria University of Wellington, New Zealand.

“Large parts of Eurasia, North Africa and Canada could potentially experience individual five-year average temperatures that exceed the 2 degree Celsius threshold by 2030 — a timescale that is not so distant,” the paper said.

Two years ago, industrialized nations set a 2 degree Celsius warming as the maximum limit to avoid dangerous climate changes including more floods, droughts and rising seas, while some experts said a 1.5 degree limit would be safer.

It is widely agreed among scientists that global pledges so far for curbing greenhouse gas emissions are not strong enough to prevent “dangerous” climate change.

Next month, nations will meet for the next U.N. climate summit in Durban, South Africa, where a binding pact to reduce emissions looks unlikely to be delivered.

Instead, a global deal might not emerge until 2014 or 2015.

The study found that most of the world’s land surface is very likely to experience five-year average temperatures that exceed 2 degrees above pre-industrial levels by 2060.

If emissions are substantially lowered, the two degree threshold might be delayed by up to several decades, it added.

However, even if global temperature rises are kept under two degrees by aggressive emissions cuts, some regions will still not avoid warming and the likelihood of extreme events such as heatwaves is still high in even a marginally warmer world.

A separate study by academics at Zurich’s Institute for Atmospheric and Climate Science, the Potsdam Institute for Climate Impact Research and the UK’s Met Office Hadley Center, among others, said it would be challenging to limit temperature rises to two degrees.

To achieve a greater than 66 percent chance of limiting temperature rise, global emissions will probably need to peak before 2020 and fall to about 44 gigatonnes of carbon dioxide equivalent by 2020.

“Without a firm commitment to put in place the mechanisms to enable an early global emissions peak followed by steep reductions thereafter, there are significant risks that the 2 degree target, endorsed by so many nations, is already slipping out of reach,” the study said.

Crop scientists now fret about heat not just water

NewsDaily: Crop scientists now fret about heat not just water.

By Christine StebbinsPosted 2011/10/24 at 10:49 am EDT

CHICAGO, Oct. 24, 2011 (Reuters) — Crop scientists in the United States, the world’s largest food exporter, are pondering an odd question: could the danger of global warming really be the heat?

Haze from forest fires engulfs La Paz city, August 23, 2010. REUTERS/David Mercado

For years, as scientists have assembled data on climate change and pointed with concern at melting glaciers and other visible changes in the life-giving water cycle, the impact on seasonal rains and irrigation has worried crop watchers most.

What would breadbaskets like the U.S. Midwest, the Central Asian steppes, the north China Plain or Argentine and Brazilian crop lands be like without normal rains or water tables?

Those were seen as longer-term issues of climate change.

But scientists now wonder if a more immediate issue is an unusual rise in day-time and, especially, night-time summer temperatures being seen in crop belts around the world.

Interviews with crop researchers at American universities paint the same picture: high temperatures have already shrunken output of many crops and vegetables.

“We don’t grow tomatoes in the deep South in the summer. Pollination fails,” said Ken Boote, a crop scientist with the University of Florida.

The same goes for snap beans which can no longer be grown in Florida during the summer, he added.

“As temperatures rise we are going to have trouble maintaining the yields of crops that we already have,” said Gerald Nelson, an economist with the International Food Policy Research Institute (IFPRI) who is leading a global project initially funded by the Bill and Melinda Gates Foundation to identify new crop varieties adapted to climate change.

“When I go around the world, people are much less skeptical, much more concerned about climate change,” said David Lobell, a Stanford University agricultural scientist.

Lobell was one of three authors of a much-discussed 2011 climate study of world corn, wheat, soybean and rice yields over the last three decades (1980-2008). It concluded that heat, not rainfall, was affecting yields the most.

“The magnitude of recent temperature trends is larger than those for precipitation in most situations,” the study said.

“We took a pretty conservative approach and still found sizable impacts. They certainly are happening already and not just something that will or might happen in the future,” Lobell told Reuters in an interview.

CONCERNS GROWING

Scientists at an annual meeting of U.S. agronomists last week in San Antonio said the focus was climate change.

“Its impact on agriculture systems, impacts on crops, mitigation strategies with soil management — a whole range of questions was being asked about climate change,” said Jerry Hatfield, Laboratory Director at the National Soil Tilth Laboratory in Ames, Iowa.

“The biggest thing is high night-time temperatures have a negative impact on yield,” Hatfield added, noting that the heat affects evaporation and the life process of the crops.

“One of the consequences of rising temperatures … is to compress the life cycle of that plant. The other key consequence is that when the atmosphere gets warmer the atmospheric demand for water increases,” Hatfield said.

“These are simple things that can occur and have tremendous consequences on our ability to produce a stable supply of food or feed or fiber,” he said.

Boote at the University of Florida found that rice and sorghum plants failed to produce grain, something he calls “pollen viability,” when the average 24-hour temperature is 95 degrees Fahrenheit (35 Celsius). That equates to highs of 104 F during the day and 86 F at night, he said.

The global seed industry has set a high bar to boost crop yields by 2050 to feed a hungry world. Scientists said that the impact of heat on plant growth needs more focus and study.

“If you look at a lot of crop insurance claims, farmers say it is the lack of water that caused the plant to die,” said Wolfram Schlenker, assistant professor at Columbia University.

“But I think it’s basically different sides of the same coin because the water requirement of the plant increases tremendously if it’s hot,” he said.

“The private sector understands the threats coming from climate change and have significant research programs in regards to drought tolerance. They focus less on higher temperatures, but that’s a tougher challenge,” Nelson said.

“We are responding with a number of initatives…the primary one is focusing on drought tolerance,” said John Soper, vice president in charge of global seed development for DuPont’s Pioneer Hi-Bred, a top U.S. seed producer.

Pioneer launched a conventionally bred drought-tolerant corn hybrid seed in the western U.S. Corn Belt this spring, selected for its yield advantage over other varieties.

“We have some early results in from Texas that show that is exactly how they are behaving. They currently have a 6 percent advantage over normal products in those drought zones,” Soper said.

Roy Steiner, deputy director for agricultural development for the Bill & Melinda Gates Foundation, said the foundation is focused on current agricultural effects of climate change.

“It’s amazing that there are still people who think that it’s not changing. Everywhere we go we’re seeing greater variability, the rains are changing and the timing of the rains is creating a lot more vulnerability,” Steiner said.

“Agriculture is one of those things that needs long-term planning, and we are very short-cycled thinking,” he said. “There are going to be some real shocks to the system. Climate is the biggest challenge. Demand is not going away.”

Significant ozone hole remains over Antarctica

Significant ozone hole remains over Antarctica.

Ozone levels in the atmosphere above the South Pole dropped to a seasonal low of 102 Dobson Units Oct. 9, tied for the 10th lowest in the 26-year record. The ozone layer helps protect the planet's surface from harmful ultraviolet radiation. Every year, an ozone hole forms above the Antarctic for several weeks, because of environmental conditions and the presence of ozone-depleting chemicals. (Credit: NOAA)

ScienceDaily (Oct. 20, 2011) — The Antarctic ozone hole, which yawns wide every Southern Hemisphere spring, reached its annual peak on September 12, stretching 10.05 million square miles, the ninth largest on record. Above the South Pole, the ozone hole reached its deepest point of the season on October 9 when total ozone readings dropped to 102 Dobson units, tied for the 10th lowest in the 26-year record.

The ozone layer helps protect the planet’s surface from harmful ultraviolet radiation. NOAA and NASA use balloon-borne instruments, ground instruments, and satellites to monitor the annual South Pole ozone hole, global levels of ozone in the stratosphere, and the humanmade chemicals that contribute to ozone depletion.Watch movie online The Transporter Refueled (2015)

“The upper part of the atmosphere over the South Pole was colder than average this season and that cold air is one of the key ingredients for ozone destruction,” said James Butler, director of NOAA’s Global Monitoring Division in Boulder, Colo. Other key ingredients are ozone-depleting chemicals that remain in the atmosphere and ice crystals on which ozone-depleting chemical reactions take place.

“Even though it was relatively large, the size of this year’s ozone hole was within the range we’d expect given the levels of manmade, ozone-depleting chemicals that continue to persist,” said Paul Newman, chief atmospheric scientist at NASA’s Goddard Space Flight Center.

Levels of most ozone-depleting chemicals are slowly declining due to international action, but many have long lifetimes, remaining in the atmosphere for decades. Scientists around the world are looking for evidence that the ozone layer is beginning to heal, but this year’s data from Antarctica do not hint at a turnaround.

In August and September (spring in Antarctica), the sun begins rising again after several months of darkness. Circumpolar winds keep cold air trapped above the continent, and sunlight-sparked reactions involving ice clouds and humanmade chemicals begin eating away at the ozone. Most years, the conditions for ozone depletion ease by early December, and the seasonal hole closes.

Levels of most ozone-depleting chemicals in the atmosphere have been gradually declining since an international treaty to protect the ozone layer, the 1987 Montreal Protocol, was signed. That international treaty caused the phase out of ozone-depleting chemicals, then used widely in refrigeration, as solvents and in aerosol spray cans.

Global atmospheric models predict that stratospheric ozone could recover by the middle of this century, but the ozone hole in the Antarctic will likely persist one to two decades beyond that, according to the latest analysis by the World Meteorological Organization, the 2010 Ozone Assessment, with co-authors from NOAA and NASA.

Researchers do not expect a smooth, steady recovery of Antarctic ozone, because of natural ups and downs in temperatures and other factors that affect depletion, noted NOAA ESRL scientist Bryan Johnson. Johnson helped co-author a recent NOAA paper that concluded it could take another decade to begin discerning changes in the rates of ozone depletion.

Johnson is part of the NOAA team tracks ozone depletion around the globe and at the South Pole with measurements made from the ground, in the atmosphere itself and by satellite. Johnson’s “ozonesonde” group has been using balloons to loft instruments 18 miles into the atmosphere for 26 years to collect detailed profiles of ozone levels from the surface up. The team also measures ozone with satellite and ground-based instruments.

This November marks the 50th anniversary of the start of total ozone column measurements by the NOAA Dobson spectrophotometer instrument at South Pole station. Ground-based ozone column measurements started nearly two decades before the yearly Antarctic ozone hole began forming, therefore helping researchers to recognize this unusual change of the ozone layer.

NASA measures ozone in the stratosphere with the Ozone Monitoring Instrument (OMI) aboard the Aura satellite. OMI continues a NASA legacy of monitoring the ozone layer from space that dates back to 1972 and the launch of the Nimbus-4 satellite.


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Producer : Mark Bienstock, Jason Blum, M. Night Shyamalan.
Release : January 19, 2017
Country : United States of America.
Production Company : Universal Pictures, Blumhouse Productions, Blinding Edge Pictures.
Language : English.
Runtime : 117 min.
Genre : Horror, Thriller.

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The vanishing Arctic lakes

Strange case of the vanishing Arctic lakes – environment – 17 October 2011 – New Scientist.

 

 

THE lake-spotted landscape of Canada is home to a watery mystery. According to a painstaking satellite survey of 1.3 million lakes stretching from coast to coast, the country lost 6700 square kilometres – or 1.2 per cent – of its water surface area between 2000 and 2009. Yet what we know about the physical processes at play suggests the lakes should be growing, not shrinking.

Whatever the cause, the loss could impact local wildlife and human populations. “It’s an important finding. We need to find out what’s driving it,” says Larry Hinzman, director of the International Arctic Research Center in Fairbanks, Alaska. The comprehensiveness of the study makes it significant, he says.

Ten years is long enough that this could be a sign of climate change, Hinzman says, “and it’s over a large enough area that it’s bound to have ecosystem and climate impacts”. Migratory water fowl, aquatic life, and indigenous people who rely on the lakes for food and water may all face challenges if the drying continues.

Shrinking Arctic lakes have been observed before, but only in the southern-most part of the Arctic, where warming trends have melted permafrost and allowed lakes to drain into the soil. The new survey, carried out by Mark Carroll at the University of Maryland in College Park, finds just the reverse: northern lakes appear to be shrinking, while southern ones are not (Geophysical Research Letters, DOI: 10.1029/2011GL049427).

This is surprising, says Hinzman, not least because evidence suggests that the northern region received higher-than-average amounts of rain during the study period. “You would expect more precipitation to lead to higher lake levels,” says atmospheric scientist Stephen Dery at the University of Northern British Columbia in Prince George. “But here, it doesn’t.”

Much of the lake water comes from the seasonal snow pack melt. In theory, warmer temperatures across the region should be decreasing the snow pack – which should also boost the lakes. Another factor at play could be the delicate balance between precipitation and evaporation which Arctic lake levels depend on: warmer temperatures and higher winds could cause more evaporation. Hinzman and Dery say melting permafrost may also be involved. That would allow lake water to soak into thawed soil, but Carroll is not aware of any evidence that the permafrost in the far north is melting yet.

The water loss could affect the amount of greenhouse gases emitted by the region’s ecosystems. When lakes dry up, the sediment in the newly exposed soil can release carbon dioxide. But standing water can also release methane, so the lake shrinkage could lower methane levels. It remains to be seen whether the net result is to boost global warming or if the impacts offset each other.

Beyond the Worst Case Climate Change Scenario

State of the Science: Beyond the Worst Case Climate Change Scenario: Scientific American.

Or, ‘expecting what is likely to actually happen’; an OLD article but still relevant

Climate change is “unequivocal” and it is 90 percent certain that the “net effect of human activities since 1750 has been one of warming,” the Intergovernmental Panel on Climate Change (IPCC) —a panel of more than 2,500 scientists and other experts—wrote in its first report on the physical science of global warming earlier this year. In its second assessment, the IPCC stated that human-induced warming is having a discernible influence on the planet, from species migration to thawing permafrost. Despite these findings, emissions of the greenhouse gases driving this process continue to rise thanks to increased burning of fossil fuels while cost-effective options for decreasing them have not been adopted, the panel found in its third report.

The IPCC’s fourth and final assessment of the climate change problem—known as the Synthesis Report—combines all of these reports and adds that “warming could lead to some impacts that are abrupt or irreversible, depending upon the rate and magnitude of the climate change.” Although countries continue to debate the best way to address this finding, 130 nations, including the U.S., China, Australia, Canada and even Saudi Arabia, have concurred with it.

“The governments now require, in fact, that the authors report on risks that are high and ‘key’ because of their potentially very high consequence,” says economist Gary Yohe?, a lead author on the IPCC Synthesis Report. “They have, perhaps, given the planet a chance to save itself.”

Among those risks:

Warming Temperatures—Continued global warming is virtually certain (or more than 99 percent likely to occur) at this point, leading to both good and bad impacts. On the positive side, fewer people will die from freezing temperatures and agricultural yield will increase in colder areas. The negatives include reduced crop production in the tropics and subtropics, increased insect outbreaks, diminished water supply caused by dwindling snowpack, and increasingly poor air quality in cities.

Heat Waves—Scientists are more than 90 percent certain that episodes of extreme heat will increase worldwide, leading to increased danger of wildfires, human deaths and water quality issues such as algal blooms.

Heavy Rains—Scientific estimates suggest that extreme precipitation events—from downpours to whiteouts—are more than 90 percent likely to become more common, resulting in diminished water quality and increased flooding, crop damage, soil erosion and disease risk.

Drought—Scientists estimate that there is a more than 66 percent chance that droughts will become more frequent and widespread, making water scarcer, upping the risk of starvation through failed crops and further increasing the risk of wildfires.

Stronger Storms—Warming ocean waters will likely increase the power of tropical cyclones (variously known as hurricanes and typhoons), raising the risk of human death, injury and disease as well as destroying coral reefs and property.

Biodiversity—As many as a third of the species known to science may be at risk of extinction if average temperatures rise by more than 1.5 degrees Celsius.

Sea Level Rise—The level of the world’s oceans will rise, likely inundating low-lying land, turning freshwater brackish and potentially triggering widespread migration of human populations from affected areas.

“As temperatures rise, thermal expansion will lead to sea-level rise, independent of melting ice,” says chemical engineer Lenny Bernstein?, another lead author of the recent IPCC report. “The indications are that this factor alone could cause serious problems [and] ice-sheet melting would greatly accelerate [it].”

Such ice-sheet melting, which the IPCC explicitly did not include in its predictions of sea-level rise, has already been observed and may be speeding up, according to recent research that determined that the melting of Greenland’s ice cap has accelerated to six times the average flow of the Colorado River. Research has also shown that the world has consistently emitted greenhouse gases at the highest projected levels examined and sea-level rise has also outpaced projections from the IPCC’s last assessment in 2001.

“We are above the high scenario now,” says climatologist Stephen Schneider of Stanford University, an IPCC lead author. “This is not a safe world.”

Other recent findings include:

Carbon Intensity Increasing—The amount of carbon dioxide per car built, burger served or widget sold had been consistently declining until the turn of the century. But since 2000, CO2 emissions have grown by more than 3 percent annually. This is largely due to the economic booms in China and India, which rely on polluting coal to power production. But emissions in the developed world have started to rise as well, increasing by 2.6 percent since 2000, according to reports made by those countries to the United Nations Framework Convention on Climate Change. Researchers at the Massachusetts Institute of Technology also recently argued that U.S. emissions may continue to increase as a result of growing energy demand.

Carbon Sinks Slowing—The world’s oceans and forests are absorbing less of the CO2 released by human activity, resulting in a faster rise in atmospheric levels of greenhouse gases. All told, humanity released 9.9 billion metric tons (2.18 X 1013 pounds) of carbon in 2006 at the same time that the ability of the North Atlantic to take in such emissions, for example, dropped by 50 percent.

Impacts Accelerating—Warming temperatures have prompted earlier springs in the far north and have caused plant species to spread farther into formerly icy terrain. Meanwhile, sea ice in the Arctic reached a record low this year, covering just 1.59 million square miles and thus shattering the previous 2005 minimum of 2.05 million square miles.

“The observed rate of loss is faster than anything predicted,” says senior research scientist Mark Serreze of the U.S. National Snow and Ice Data Center in Boulder, Colo. “We’re already set up for another big loss next year. We’ve got so much open water in the Arctic now that has absorbed so much energy over the summer that the ocean has warmed. The ice that grows back this autumn will be thin.”

The negative consequences of such reinforcing, positive feedbacks (white ice is replaced by dark water, which absorbs more energy and prevents the formation of more white ice) remain even when they seemingly work in our favor.

For example, scientists at the Leibniz Institute of Marine Sciences at the University of Kiel in Germany recently discovered that plankton consumes more carbon at higher atmospheric concentrations of CO2. “The plankton were carbon-enriched,” says marine biologist Ulf Riebesell, who conducted the study. “There weren’t more of them, but each cell had more carbon.”

This could mean that microscopic ocean plants may potentially absorb more of the carbon emitted into the atmosphere. Unfortunately, other research (from the Woods Hole Oceanographic Institution) has shown that such plankton does not make it to the seafloor in large enough amounts to sequester the carbon in the long term.

Further, such carbon-heavy plankton do not begin to appear until CO2 concentrations reach twice present values—750 parts per million (ppm) in the atmosphere compared with roughly 380 ppm presently (a level at which catastrophic change may be a certainty)—and they are less nutritious to all the animals that rely on them for food. “This mechanism is both too small and too late,” Riebesell says. “By becoming more carbon-rich, zooplankton have to eat more phytoplankton to achieve the same nutrition” and, therefore, “they grow and reproduce more slowly.”

The IPCC notes that there are cost-effective solutions, such as retrofitting buildings for energy efficiency, but says they must be implemented in short order to stem further damage. “We are 25 years too late,” Schneider says. “If the object is to avoid dangerous change, we’ve already had it. The object now is to avoid really dangerous change.”

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