tagged w/ Climate Science
WASHINGTON (AP) — The old saying that "what goes up must come down" doesn't apply to carbon dioxide pollution in the air, which just hit an unnerving milestone.
The chief greenhouse gas was measured Thursday at 400 parts per million in Hawaii, a monitoring site that sets the world's benchmark. It's a symbolic mark that scientists and environmentalists have been anticipating for years.
While this week's number has garnered all sorts of attention, it is just a daily reading in the month when the chief greenhouse gas peaks in the Northern Hemisphere. It will be lower the rest of the year. This year will probably average around 396 ppm. But not for long — the trend is going up and at faster and faster rates.
Within a decade the world will never see days — even in the cleanest of places on days in the fall when greenhouse gases are at their lowest — when the carbon measurement falls below 400 ppm, said James Butler, director of global monitoring at the National Oceanic and Atmospheric Administration's Earth Science Research Lab in Boulder, Colo.
"The 400 is a reminder that our emissions are not only continuing, but they're accelerating; that's a scary thing," Butler said Saturday. "We're stuck. We're going to keep going up."
Carbon dioxide stays in the air for a century, some of it into the thousands of years. And the world carbon dioxide pollution levels are accelerating yearly. Every second, the world's smokestacks and cars pump 2.4 million pounds of the heat-trapping gas into the air.
Carbon pollution levels that used to be normal for the 20th century are fast becoming history in the 21st century.
"It means we are essentially passing one in a whole series of points of no return," said Michael Mann, a climate scientist at Pennsylvania State University.
Princeton University climate scientist Michael Oppenheimer said the momentum in carbon dioxide emissions has the world heading toward and passing 450 ppm. That is the level which would essentially mean the world warms another 2 degrees, what scientists think of as dangerous, he said. That 2-degree mark is what much of the world's nations have set as a goal to prevent.
"The direction we've seen is for blowing through the best benchmark for what's dangerous change," Oppenheimer said.
And to see what the future is, scientists look to the past.
The last time the worldwide carbon level probably hit 400 ppm was about 2 million years ago, said Pieter Tans of the National Oceanic and Atmospheric Administration.
That was during the Pleistocene Era. "It was much warmer than it is today," Tans said. "There were forests in Greenland. Sea level was higher, between 10 and 20 meters (33 to 66 feet)."
Other scientists say it may have been 10 million years ago that Earth last encountered this much carbon dioxide in the atmosphere. The first modern humans only appeared in Africa about 200,000 years ago.
Environmental activists, such as former Vice President Al Gore, seized on the milestone.
"This number is a reminder that for the last 150 years — and especially over the last several decades — we have been recklessly polluting the protective sheath of atmosphere that surrounds the Earth and protects the conditions that have fostered the flourishing of our civilization," Gore said in a statement. "We are altering the composition of our atmosphere at an unprecedented rate."
Carbon dioxide traps heat just like in a greenhouse. It accounts for three-quarters of the planet's heat-trapping gases. There are others, such as methane, which has a shorter life span but traps heat more effectively. Both trigger temperatures to rise over time, scientists say, which is causing sea levels to rise and some weather patterns to change.
When measurements of carbon dioxide were first taken in 1958, it measured 315 ppm. Some scientists and environmental groups promote 350 ppm as a safe level for CO2, but scientists acknowledge they don't really know what levels would stop the effects of global warming.
The level of carbon dioxide in the air is rising faster than in the past decades, despite international efforts by developed nations to curb it. On average the amount is growing by about 2 ppm per year. That's 100 times faster than at the end of the Ice Age.
Back then, it took 7,000 years for carbon dioxide to reach 80 ppm, Tans said. Because of the burning of fossil fuels, such as oil and coal, carbon dioxide levels have gone up by that amount in just 55 years.
Before the Industrial Revolution, carbon dioxide levels were around 280 ppm, and they were closer to 200 during the Ice Age, which is when sea levels shrank and polar places went from green to icy. There are natural ups and downs of this greenhouse gas, which comes from volcanoes and decomposing plants and animals. But that's not what has driven current levels so high, Tans said. He said the amount should be even higher, but the world's oceans are absorbing quite a bit, keeping it out of the air.
"What we see today is 100 percent due to human activity," said Tans, a NOAA senior scientist. The burning of fossil fuels, such as coal for electricity and oil for gasoline, has caused the overwhelming bulk of the man-made increase in carbon in the air, scientists say.
More at the linkWASHINGTON (AP) — The old saying that "what goes up must come down"... more
The Prize is “presented to an individual in recognition of his or her courageous and life-long defense of the public interest and passionate commitment to social justice.”
By Joe Romm on Apr 24, 2013 at 6:33 pm
James Hansen was awarded the Ridenhour Courage Prize today. I was given the great privilege of introducing Hansen. This is what I prepared:
Dr. James Hansen is being honored today in part because he told Congress: “The global warming now is large enough that we can ascribe with a high degree of confidence a cause-and-effect relationship to the greenhouse effect.”
The courageous part isn’t what he said, it’s when he said it — 25 years ago, during the sweltering summer of 1988. It was the first high-profile public statement by a US government scientist alerting the country to this grave threat.
Jim embodies the Ridenhour Courage Prize. When he was still NASA’s top climate scientist, he blew the whistle on government efforts to silence him — and others — on climate change.
Jim is a modern day Paul Revere … if Paul Revere’s midnight ride had taken place in 1750 and the message was, “The British are coming, The British are coming — in 25 years.”
Yes, climate change is a challenging story to tell. And Jim has actually been telling it publicly since 1981, when he published his first warning that led to a major New York Times story, headlined, “Study Finds Warming Trend That Could Raise Sea Levels.”
And yet carbon pollution has kept rising. We live in a spineless world, where being scientifically right for over 30 years gives you no more credit with the national media than being a professional disinformer funded by the fossil fuel industry.
How spineless is this world? If a doctor used the best science to diagnose a smoker as having early-stage emphysema and the doctor did NOT urge the patient to start quitting cigarettes, he’d be charged with malpractice.
But if a climatologist uses the best science to diagnose an entire planet as having early-stage climate change, and he urges the world to start quitting fossil fuels, well, then he is labeled an alarmist or an extremist by industry-backed groups.
The truth is we all should be alarmed by the great moral crisis of our time. By destroying a livable climate we are stealing the future from our children and grandchildren and countless future generations.
To save this spineless world from itself, supplying the truth isn’t enough. You need to supply the spine, too. You need to be courageous. And so Jim has been forced by the times — and by his moral convictions — to become an activist.
There is a saying that applies to Jim, “One man with courage is a majority.”
How many scientists have spawned an entire movement?
Five years ago Jim explained that “If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted,” we need to return carbon dioxide levels back to 350 parts per million. That led to Bill McKibben founding the group 350.org.
Then Jim said burning the tar sands would be “game over for the climate” — and that led to the fight against the Keystone XL pipeline — and the biggest protests and civil disobedience the climate movement had ever seen.
And because Jim has the courage of his convictions he has had the courage to be convicted himself — he’s been arrested 5 times during peaceful protests.
Fifty years ago this month, another great moral crusader was arrested for protesting — and he wrote a letter from his jail cell in Birmingham explaining why. “Injustice anywhere is a threat to justice everywhere,” wrote Martin Luther King Jr. on April 16, 1963. “We are caught in an inescapable network of mutuality, tied in a single garment of destiny.”
Now more than ever, we are “tied in a single garment of destiny,” cloaked as a species in a protective climate that we are in the process of unraveling. And so the need for activism, the need for courage, the need to speak out, is as great as ever.
As King put it, “We will have to repent in this generation not merely for the vitriolic words and actions of the bad people but for the appalling silence of the good people.”
It is my singular honor to give you a man who will not have to repent, a man for all seasons, literally — the winner of the 2013 Ridenhour Courage Prize, Dr. James Hansen.The Prize is “presented to an individual in recognition of his or her courageous... more
Paul Douglas, above, gave a brief summary of what we know about the extreme spring in the US, just before the current river of moisture hit across the nation’s midsection last night.
Peter Sinclair | April 19, 2013
Near record setting flooding is hitting at my location, schools closed and evacuations underway. I got a bump from Jeff Masters last night about the situation, he is grappling with the big picture, will be posting more later today. For now, more concern about extreme weather knock-on effects – possible washing of dangerous invasive species into the Great Lakes water system.
“The rains have brought the Des Plaines River on the east side of Chicago to major flood stage this morning, and a record flood crest is expected on Friday. The Asian Carp, a dangerous invasive species that would cost billions of dollars were it to get loose in the Great Lakes, is present in the Des Plaines River. Today’s flood event is capable of washing significant numbers of Asian Carp from the Des Plaines River into a canal that feeds directly into Lake Michigan, where they might be able to set up a breeding population capable of devastating the Great Lakes’ fishing industry. However, in October 2010, the U.S. Army Corps of Engineers completed the Des Plaines River barricade, a 13-mile-long system of concrete barriers and a specially fabricated wire mesh that allows water to flow through the fence but prevents the passage of fish. Hopefully, this barricade will withstand the flood and prevent Asian Carp from washing into Lake Michigan.”
Continued at link: http://climatecrocks.com/2013/04/19/jet-stream-blows-winds-of-change/Paul Douglas, above, gave a brief summary of what we know about the extreme spring in... more
Current climate-induced drought is slipping into a trend that scientists say resembles some of the worst droughts in U.S. history, like the Dust Bowl.
By Katherine Bagley,
Drought conditions in more than half of the United States have slipped into a pattern that climatologists say is uncomfortably similar to the most severe droughts in recent U.S. history, including the 1930s Dust Bowl and the widespread 1950s drought.
The 2013 drought season is already off to a worse start than in 2012 or 2011—a trend that scientists at the National Oceanic and Atmospheric Administration (NOAA) say is a good indicator, based on historical records, that the entire year will be drier than last year, even if spring and summer rainfall and temperatures remain the same. If rainfall decreases and temperatures rise, as climatologists are predicting will happen this year, the drought could be even more severe.
The federal researchers also say there is less than a 20 percent chance the drought will end in the next six months.
"There were certainly pockets of drought as we went into spring last year, but overall, the situation was much better than it is now," said Tom Karl, a climatologist and director of NOAA's National Climatic Data Center. "We are going to have to watch really closely ... Last year was bad enough."
In February, 54.2 percent of the contiguous United States experienced drought conditions, compared to 39 percent at the same time last year. Large swaths of South Dakota, Wyoming, Nebraska and Montana—which entered last year's major agricultural growing season with very moist conditions—are now battling severe and extreme drought as farmers get ready to plant their spring crops.
The outlooks for rainfall and temperature are similarly bleak.
NOAA's Climate Prediction Center forecast last week that Texas, Oklahoma and the Pacific Northwest will likely get less rainfall in 2013 than in 2012, and that the entire nation will experience a warmer summer than last year.
More at the linkCurrent climate-induced drought is slipping into a trend that scientists say resembles... more
“If you believe in the Bible, one would have to say the Great Flood is an example of climate change. That certainly wasn't because man had overdeveloped hydrocarbon energy.”
By Andrew Kaczynski | April 10, 2013
Texas Rep. Joe Barton made those remarks Wednesday at the Subcommittee on Energy and Power hearing on H.R. 3, the Northern Route Approval Act, a bill that would give Congress the authority approve the Keystone pipeline.
"I don't think it's a secret that I'm a proponent and supporter of the Keystone pipeline," Barton said.
Barton continued to say he didn't deny the climate was changing, but argued that the change was due to natural causes, as he has in the past.
"I would point out that people like me who support hydrocarbon development don't deny that climate is changing," he added. "I think you can have an honest difference of opinion of what's causing that change without automatically being either all in that's all because of mankind or it's all just natural. I think there's a divergence of evidence."
Barton then cited the biblical Great Flood as an example of climate change not caused by man.
"I would point out that if you're a believer in the Bible, one would have to say the Great Flood is an example of climate change and that certainly wasn't because mankind had overdeveloped hydrocarbon energy."“If you believe in the Bible, one would have to say the Great Flood is an... more
James E. Hansen of NASA, retiring this week, reflected in a window at his farm in Pennsylvania.
By Justin Gillis | April 1, 2013
Photo: Michael Nagle for The New York Times
James E. Hansen, the climate scientist who issued the clearest warning of the 20th century about the dangers of global warming, will retire from NASA this week, giving himself more freedom to pursue political and legal efforts to limit greenhouse gases.
His departure, after a 46-year career at the space agency’s Goddard Institute for Space Studies in Manhattan, will deprive federally sponsored climate research of its best-known public figure.
At the same time, retirement will allow Dr. Hansen to press his cause in court. He plans to take a more active role in lawsuits challenging the federal and state governments over their failure to limit emissions, for instance, as well as in fighting the development in Canada of a particularly dirty form of oil extracted from tar sands.
“As a government employee, you can’t testify against the government,” he said in an interview.
Dr. Hansen had already become an activist in recent years, taking vacation time from NASA to appear at climate protests and allowing himself to be arrested or cited a half-dozen times.
But those activities, going well beyond the usual role of government scientists, had raised eyebrows at NASA headquarters in Washington. “It was becoming clear that there were people in NASA who would be much happier if the ‘sideshow’ would exit,” Dr. Hansen said in an e-mail.
At 72, he said, he feels a moral obligation to step up his activism in his remaining years.
“If we burn even a substantial fraction of the fossil fuels, we guarantee there’s going to be unstoppable changes” in the climate of the earth, he said. “We’re going to leave a situation for young people and future generations that they may have no way to deal with.”
His departure, on Wednesday, will end a career of nearly half a century working not just for a single agency but also in a single building, on the edge of the Columbia University campus.
From that perch, seven floors above the diner made famous by “Seinfeld,” Dr. Hansen battled the White House, testified dozens of times in Congress, commanded some of the world’s most powerful computers and pleaded with ordinary citizens to grasp the basics of a complex science.
His warnings and his scientific papers have drawn frequent attack from climate-change skeptics, to whom he gives no quarter. But Dr. Hansen is a maverick, just as likely to vex his allies in the environmental movement. He supports nuclear power and has taken stands that sometimes undercut their political strategy in Washington.
In the interview and in subsequent e-mails, Dr. Hansen made it clear that his new independence would allow him to take steps he could not have taken as a government employee. He plans to lobby European leaders — who are among the most concerned about climate change — to impose a tax on oil derived from tar sands. Its extraction results in greater greenhouse emissions than conventional oil.
Dr. Hansen’s activism of recent years dismayed some of his scientific colleagues, who felt that it backfired by allowing climate skeptics to question his objectivity. But others expressed admiration for his willingness to risk his career for his convictions.
Initially, Dr. Hansen plans to work out of a converted barn on his farm in Pennsylvania. He has not ruled out setting up a small institute or taking an academic appointment.
He said he would continue publishing scientific papers, but he will no longer command the computer time and other NASA resources that allowed him to track the earth’s rising temperatures and forecast the long-run implications.
Dr. Hansen, raised in small-town Iowa, began his career studying Venus, not the earth. But as concern arose in the 1970s about the effects of human emissions of greenhouse gases, he switched gears, publishing pioneering scientific papers.
His initial estimate of the earth’s sensitivity to greenhouse gases was somewhat on the high side, later work showed. But he was among the first scientists to identify the many ways the planet is likely to respond to rising temperatures and to show how those effects would reinforce one another to produce immense changes in the climate and environment, including a sea level rise that could ultimately flood many of the world’s major cities.
“He’s done the most important science on the most important question that there ever was,” said Bill McKibben, a climate activist who has worked closely with Dr. Hansen.
Around the time Dr. Hansen switched his research focus, in the 1970s, a sharp rise in global temperatures began. He labored in obscurity over the next decade, but on a blistering June day in 1988 he was called before a Congressional committee and testified that human-induced global warming had begun.
Speaking to reporters afterward in his flat Midwestern accent, he uttered a sentence that would appear in news reports across the land: “It is time to stop waffling so much and say that the evidence is pretty strong that the greenhouse effect is here.”
Given the natural variability of climate, it was a bold claim to make after only a decade of rising temperatures, and to this day some of his colleagues do not think he had the evidence.
Yet subsequent events bore him out. Since the day he spoke, not a single month’s temperatures have fallen below the 20th-century average for that month. Half the world’s population is now too young to have lived through the last colder-than-average month, February 1985.
In worldwide temperature records going back to 1880, the 19 hottest years have all occurred since his testimony.
Again and again, Dr. Hansen made predictions that were ahead of the rest of the scientific community and, arguably, a bit ahead of the evidence.
“Jim has a real track record of being right before you can actually prove he’s right with statistics,” said Raymond T. Pierrehumbert, a planetary scientist at the University of Chicago.
Continued at linkJames E. Hansen of NASA, retiring this week, reflected in a window at his farm in... more
By Karl Ritter
Saturday March 30, 2013
STOCKHOLM -- Is it Easter or Christmas? Many Europeans would be forgiven for being confused by winter’s icy grip on lands that should be thawing in springtime temperatures by now.
Britain is on track for the coldest March since 1962, according to national weather service the Met Office, which also says daily low temperatures in London are going to remain below freezing through the Easter holiday. The mean temperature in Britain from March 1-26 was 2.5 C (36.5 F) -- three degrees below the long-term average.
In Berlin, Good Friday saw a new round of snowfall and temperatures just above freezing. The city’s popular lakeside beach opened for the season as planned, though it wasn’t exactly beach weather. Some visitors built a snowman and few ventured into the freezing water.
What’s going on?
As always when you talk about weather, natural variability is a big factor. But an increasing body of research suggests that cold spells like the one that has lingered in northern and central Europe for much of March could become more common as a result of global warming melting the Arctic ice cap.
Q: Why is it so cold in much of Europe right now?
A: Normally, European winters are kept relatively mild by wet, westerly winds from the Atlantic. But in March, the wind has been blowing mostly from the northeast, bringing freezing Arctic air down over much of Europe.
Q: So why are the winds coming from the northeast?
A: The winds are driven by atmospheric circulation patterns which in turn are affected by differences in air pressure between northern and southern latitudes. For much of March this circulation has been in a negative state, meaning the pressure difference is small. That weakens the westerly Atlantic winds and paves the way for cold air to sweep down over Europe from the Arctic and Siberia.
Q: What does that have to do with Arctic sea ice?
A: Global warming is melting the ice cap over the Arctic Ocean. Last September, it reached its lowest extent on record. Climate models show that the loss of sea ice -- which acts as a lid on the ocean, preventing it from giving off heat -- triggers feedback mechanisms that shake up the climate system further. A series of studies in recent years have shown that one such effect could be changes in atmospheric circulation, resulting in more frequent cold snaps in Europe.
Q: How would melting Arctic ice lead to cold snaps?
A: The theory is the loss of sea ice means more heat is released from the open ocean, warming the layer of polar air over the water. That reduces the temperature and air pressure differentials with more southern latitudes, increasing the likelihood of a negative state in the atmospheric circulation. Experts stress that winter weather is affected by many other factors, but several studies have shown the Arctic melt loads the dice in favor of colder and snowier winters in Europe. One study by scientists at the Potsdam Institute for Climate Impact Research in Germany showed European cold snaps could become three times more likely because of shrinking sea ice.
Q: What’s the impact on the jet stream?
A: Some studies suggest that the shrinking sea ice also shifts the polar jet stream, a high-altitude air current that flows from west to east. Bigger waves in the meandering jet stream allow frigid air to spill southward from the Arctic, they say. Other climate experts are uncertain about this effect, saying more research is needed.
Nature 458, 1158-1162 (30 April 2009) | doi:10.1038/nature08017; Received 25 September 2008; Accepted 25 March 2009
Greenhouse-gas emission targets for limiting global warming to 2 °C
See associated Correspondence: Victor, Nature 459, 909 (June 2009)
Malte Meinshausen1, Nicolai Meinshausen2, William Hare1,3, Sarah C. B. Raper4, Katja Frieler1, Reto Knutti5, David J. Frame6,7 & Myles R. Allen7
1.Potsdam Institute for Climate Impact Research, Telegraphenberg, 14412 Potsdam, Germany
2.Department of Statistics, University of Oxford, South Parks Road, Oxford OX1 3TG, UK
3.Climate Analytics, Telegraphenberg, 14412 Potsdam, Germany
4.Centre for Air Transport and the Environment, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK
5.Institute for Atmospheric and Climate Science, ETH Zurich, 8092 Zurich, Switzerland
6.Smith School of Enterprise and the Environment, University of Oxford, Oxford OX1 2BQ, UK
7.Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, UK
Correspondence to: Malte Meinshausen1 Correspondence and requests for materials should be addressed to M.M.
More than 100 countries have adopted a global warming limit of 2 °C or below (relative to pre-industrial levels) as a guiding principle for mitigation efforts to reduce climate change risks, impacts and damages1, 2. However, the greenhouse gas (GHG) emissions corresponding to a specified maximum warming are poorly known owing to uncertainties in the carbon cycle and the climate response. Here we provide a comprehensive probabilistic analysis aimed at quantifying GHG emission budgets for the 2000–50 period that would limit warming throughout the twenty-first century to below 2 °C, based on a combination of published distributions of climate system properties and observational constraints. We show that, for the chosen class of emission scenarios, both cumulative emissions up to 2050 and emission levels in 2050 are robust indicators of the probability that twenty-first century warming will not exceed 2 °C relative to pre-industrial temperatures. Limiting cumulative CO2 emissions over 2000–50 to 1,000 Gt CO2 yields a 25% probability of warming exceeding 2 °C—and a limit of 1,440 Gt CO2 yields a 50% probability—given a representative estimate of the distribution of climate system properties. As known 2000–06 CO2 emissions3 were ~234 Gt CO2, less than half the proven economically recoverable oil, gas and coal reserves4, 5, 6 can still be emitted up to 2050 to achieve such a goal. Recent G8 Communiqués7 envisage halved global GHG emissions by 2050, for which we estimate a 12–45% probability of exceeding 2 °C—assuming 1990 as emission base year and a range of published climate sensitivity distributions. Emissions levels in 2020 are a less robust indicator, but for the scenarios considered, the probability of exceeding 2 °C rises to 53–87% if global GHG emissions are still more than 25% above 2000 levels in 2020.
It really is simple physics. We've pushed the climate system to the point where it is pushing back. If we were paying attention on the whole and were smarter about such things we would know to stop pushing so hard before it breaks. Judging from the early cracks in Arctic ice we've yet to get that message on the whole.
Planting trees is great and we are all for it. However, in concert with that we need laws and we need to keep the oil and tarsands IN THE GROUND as well as preserving what we already planted. An "all of the above" energy policy will also NOT bring us to the goal outlined in this peer reviewed paper.By Karl Ritter
Saturday March 30, 2013
STOCKHOLM -- Is it Easter or Christmas? Many... more
While many on the right have changed their tune recently, the latest influx of 100 new teabagging Republican dolts in congress includes about half that are unbelievably still climate change skeptics. This serves to prove that big oil companies have not lost their grip on some of the 'less virtuous' of our lawmakers...
http://veracitystew.com/?p=48376While many on the right have changed their tune recently, the latest influx of 100 new... more
The National Research Council is pleased to present this video that explains how scientists have arrived at the state of knowledge about current climate change and its causes.
More at the link
The truth is incontrovertible. Malice may attack it, ignorance may deride it, but in the end, there it is."
Winston ChurchillThe National Research Council is pleased to present this video that explains how... more
Greenland Ice Cores Reveal Warm Climate of the Past
Jan. 23, 2013 — In the period between 130,000 and 115,000 years ago, Earth's climate was warmer than today. But how much warmer was it and what did the warming do to global sea levels? -- as we face global warming in the future, the answer to these questions is becoming very important. New research from the NEEM ice core drilling project in Greenland shows that the period was warmer than previously thought. The international research project is led by researchers from the Niels Bohr Institute and the very important results are published in the scientific journal, Nature.
In the last millions years Earth's climate has alternated between ice ages lasting about 100,000 years and interglacial periods of 10,000 to 15,000 years. The new results from the NEEM ice core drilling project in northwest Greenland, led by the Niels Bohr Institute at the University of Copenhagen show that the climate in Greenland was around 8 degrees C warmer than today during the last interglacial period, the Eemian period, 130,000 to 115,000 thousand years ago.
"Even though the warm Eemian period was a period when the oceans were four to eight meters higher than today, the ice sheet in northwest Greenland was only a few hundred meters lower than the current level, which indicates that the contribution from the Greenland ice sheet was less than half the total sea-level rise during that period," says Dorthe Dahl-Jensen, Professor at the Niels Bohr Institute, University of Copenhagen, and leader of the NEEM-project.
Past reveals knowledge about the climate
The North Greenland Eemian Ice Drilling project or NEEM, led by the Niels Bohr Institute, is an international project with participants from 14 countries. After four years of deep drilling, the team has drilled ice cores through the more than 2.5 kilometer thick ice sheet. The ice is a stack of layer upon layer of annual snow fall which never melts away, and as the layers gradually sink, the snow is compresses into ice. This gives thousands of annual ice layers that, like tree rings, can tell us about variations in past climate from year to year.
The ice cores are examined in laboratories with a series of analyses that reveal past climate. The content of the heavy oxygen isotope O18 in the ice cores tells us about the temperature in clouds when the snow fell, and thus of the climate of the past. The air bubbles in the ice are also examined. The air bubbles are samples of the ancient atmosphere encased in the ice and they provide knowledge about the air composition of the atmosphere during past climates.
Past global warming
The researchers have obtained the first complete ice core record from the entire previous interglacial period, the Eemian, and with the detailed studies have been able to recreate the annual temperatures -- almost 130,000 years back in time.
"It is a great achievement for science to collect and combine so many measurements on the ice core and reconstruct past climate history. The new findings show higher temperatures in northern Greenland during the Eemian than current climate models have estimated," says Professor Dorthe Dahl-Jensen, Niels Bohr Institute.
Intense melting on the surface
During the warm Eemian period, there was intense surface melting that can be seen in the ice core as layers of refrozen meltwater. Meltwater from the surface had penetrated down into the underlying snow, where it once again froze into ice. Such surface melting has occurred very rarely in the last 5,000 years, but the team observed such a melting during the summer of 2012 when they were in Greenland.
"We were completely shocked by the warm surface temperatures at the NEEM camp in July 2012," says Professor Dorthe Dahl-Jensen. "It was even raining and just like in the Eemian, the meltwater formed refrozen layers of ice under the surface. Although it was an extreme event the current warming over Greenland makes surface melting more likely and the warming that is predicted to occur over the next 50-100 years will potentially have Eemian-like climatic conditions," she believes.
Good news and bad news
During the warm Eemian period there was increased melting at the edge of the ice sheet and the dynamic flow of the entire ice mass caused the ice sheet to lose mass and it was reduced in height. The ice mass was shrinking at a very high rate of 6 cm per year. But despite the warm temperatures, the ice sheet did not disappear and the research team estimates that the volume of the ice sheet was not reduced by more than 25 percent during the warmest 6,000 years of the Eemian.
"The good news from this study is that the Greenland ice sheet is not as sensitive to temperature increases and to ice melting and running out to sea in warm climate periods like the Eemian,as we thought," explains Dorthe Dahl-Jensen and adds that the bad news is that if Greenland's ice did not disappear during the Eemian then Antarctica must be responsible for a significant portion of the 4-8 meter rise in sea levels that we know occurred during the Eemian.
This new knowledge about past warm climates may help to clarify what is in store for us now that we are facing a global warming.Greenland Ice Cores Reveal Warm Climate of the Past
Jan. 23, 2013 — In the... more
2012 was a historic year for extreme weather that included drought, wildfires, hurricanes and storms; however, tornado activity was below average
2012 marked the warmest year on record for the contiguous United States with the year consisting of a record warm spring, second warmest summer, fourth warmest winter and a warmer-than-average autumn. The average temperature for 2012 was 55.3°F, 3.2°F above the 20th century average, and 1.0°F above 1998, the previous warmest year.
The average precipitation total for the contiguous U.S. for 2012 was 26.57 inches, 2.57 inches below average, making it the 15th driest year on record for the nation. At its peak in July, the drought of 2012 engulfed 61 percent of the nation with the Mountain West, Great Plains, and Midwest experiencing the most intense drought conditions. The dry conditions proved ideal for wildfires in the West, charring 9.2 million acres — the third highest on record.
The U.S. Climate Extremes Index indicated that 2012 was the second most extreme year on record for the nation. The index, which evaluates extremes in temperature and precipitation, as well as landfalling tropical cyclones, was nearly twice the average value and second only to 1998. To date, 2012 has seen 11 disasters that have reached the $1 billion threshold in losses, to include Sandy, Isaac, and tornado outbreaks experienced in the Great Plains, Texas and Southeast/Ohio Valley.
More at the link2012 was a historic year for extreme weather that included drought, wildfires,... more
Reality and facts matter.
"Videographer Peter Sinclair captures the views of eight scientists representing some of the nation's leading research institutions in a concise video newly produced for The Yale Forum."Reality and facts matter.
"Videographer Peter Sinclair captures the views of... more
Before speaking about energy at the Western Governors Association, Arizona Gov. Jan Brewer (R) was asked about global warming by the local TV station KTVK.
"Everybody has an opinion on it, you know, and I, you know, I probably don’t believe that it’s man made," she said. "I believe that, you know, that weather elements are controlled maybe by different things."
Brewer didn't like the question. As she started walking away, she turned back toward the reporter to express her displeasure, apparently thinking the camera was off.
"Where in the hell did that come from?" she said.
The exchange was caught on tape.
(There's a bit of a dealy beforeit starts.)Before speaking about energy at the Western Governors Association, Arizona Gov. Jan... more
SAN FRANCISCO — A 200-year-long drought 4,200 years ago may have killed off the ancient Sumerian language, one geologist says.
Because no written accounts explicitly mention drought as the reason for the Sumerian demise, the conclusions rely on indirect clues. But several pieces of archaeological and geological evidence tie the gradual decline of the Sumerian civilization to a drought.
The findings, which were presented Monday (Dec. 3) here at the annual meeting of the American Geophysical Union, show how vulnerable human society may be to climate change, including human-caused change.
"This was not a single summer or winter, this was 200 to 300 years of drought," said Matt Konfirst, a geologist at the Byrd Polar Research Center.
Beginning about 3500 B.C., the Sumerian culture flourished in ancient Mesopotamia, which was located in present-day Iraq. Ancient Sumerians invented cuneiform writing, built the world's first wheel and arch, and wrote the first epic poem, "Gilgamesh." [Image Gallery: Ancient Middle-Eastern Texts]
But after 200 to 300 years of upheaval, the Sumerian culture disappeared around 4,000 years ago, and the Sumerian language went extinct soon after that.
Konfirst wanted to see if a drought that spanned about 200 years may have caused the decline. Several geological records point to a long period of drier weather in the Middle East around 4,200 years ago, Konfirst said. The Red Sea and the Dead Sea had increased evaporation; water levels dropped at Lake Van in Turkey, and cores from marine sediments around that period indicate increased dust in the environment.
"As we go into the 4,200-year-ago climate anomaly, we actually see that estimated rainfall decreases substantially in this region and the number of sites that are populated at this time period reduce substantially," he said.
Around the same time, 74 percent of the ancient Mesopotamian settlements were abandoned, according to a 2006 study of an archaeological site called Tell Leilan in Syria. The populated area also shrank by 93 percent, he said.
"People still live in this region. It's not that the collapse of a civilization means that an area is completely abandoned," he said. "But that there's a sharp change in the population."
During the great drought, two waves of marauding nomads descended upon the region, sacking the capital city of Ur. After around 2000 B.C., ancient Sumerian gradually died off as a spoken language in the region. For the next 2,000 years, the tongue lingered on as a dead written language, similar to Latin in the Middle Ages, but has been completely extinct since then, Konfirst said.
The coincidence of the social upheaval, depopulation in the area and the geologic record of drought suggests climate change might have played a role in the loss of the Sumerian language, Konfirst said.
The findings also suggest that modern-day civilizations may be vulnerable to climate change, he said.SAN FRANCISCO — A 200-year-long drought 4,200 years ago may have killed off the... more
Dirty energy is bringing us dirty weather. This is the reality we face as we now see natural processes being pushed to their limits and they are pushing back. More severe and frequent heatwaves, floods, wildfires, storms and droughts now being dubbed the "new normal" are not normal and they are costing us in lives, biodiversity and our economy.
24 Hours of Reality, the Dirty Weather Report will be a live streaming 24 hour event from Nov. 14 -15 travelling around the globe to bring the reality of the effects of dirty energy and dirty weather to the world's consciousness.
We are truly at a crossroads as a civilization and if we are to give our children a chance we have to join in the solutions now. I am proud to be a leader spreading the truth about the science of climate change and what it is now doing to our planet and the solutions still within our reach. Thank you Mr. Gore for your tireless perseverence and passion in working to make the world a better place. I love you with all of my heart.Dirty energy is bringing us dirty weather. This is the reality we face as we now see... more
During the past week, drought conditions have improved slightly across the U.S., but the majority of the lower 48 states continue to suffer from what is proving to be a widespread and pernicious drought event, according to the latest U.S. Drought Monitor statistics, released on Thursday. The drought put a major dent in the U.S. corn and soybean crop, and now it is delaying the emergence of winter wheat, which is grown in some of the hardest-hit drought states, such as Nebraska.
Two storm systems brought rain to the middle of the country during the past week, and that was enough to knock the drought footprint down from 63.55 percent of the contiguous U.S. to 62.39 percent. All categories of drought show slight improvements, including “exceptional drought,” which is the worst category. On October 9, 6.18 percent of the lower 48 states was experiencing exceptional drought conditions, but as of October 16, that had fallen to 5.84 percent. It may not be much of a gain, but any improvement is welcome news to those who have been impacted by what has already been the worst drought event since the 1950s, and is comparable in some ways to the Dust Bowl droughts of the 1930s.
According to Eric D. Luebehusen, a meteorologist at the Agriculture Department’s Office of the Chief Economist, 68 percent of the U.S. winter wheat crop is in drought. More than a third of the crop had emerged, but in Colorado, Montana, Nebraska, and South Dakota, the emergence of the crop was running well below average.
Nebraska, the hardest-hit state, saw scant improvement, with the portion of the state in exceptional drought dropping slightly to 95.31 percent from 97.94 percent. More significant improvement occurred in Oklahoma, where extreme to exceptional drought fell from 95.70 percent on Oct. 9 to just 77.8 percent on Oct. 16. Other improvements occurred in Arkansas, Iowa, Kansas, Missouri, and Wisconsin.
Drought conditions did expand, though, in parts of the Upper Midwest and Plains states, such as in Minnesota and the Dakotas. According to the winter outlook that the National Oceanic and Atmospheric Administration (NOAA) released on Thursday, these regions are likely to see a drier and warmer-than-average winter, although they are currently having a colder-than-average fall. The Western U.S., in general, is projected to be drier-than-average this winter, and drought conditions are forecast to spread westward from the Plains to the Pacific Northwest, and then southward down the West Coast to Central, and possibly even Southern, California.
More at the linkDuring the past week, drought conditions have improved slightly across the U.S., but... more
ScienceDaily (Oct. 16, 2012) — Some 41,000 years ago, a complete and rapid reversal of the geomagnetic field occured. Magnetic studies of the GFZ German Research Centre for Geosciences on sediment cores from the Black Sea show that during this period, during the last ice age, a compass at the Black Sea would have pointed to the south instead of north.
Moreover, data obtained by the research team formed around GFZ researchers Dr. Norbert Nowaczyk and Prof. Helge Arz, together with additional data from other studies in the North Atlantic, the South Pacific and Hawaii, prove that this polarity reversal was a global event. Their results are published in the latest issue of the scientific journal Earth and Planetary Science Letters.
What is remarkable is the speed of the reversal: "The field geometry of reversed polarity, with field lines pointing into the opposite direction when compared to today's configuration, lasted for only about 440 years, and it was associated with a field strength that was only one quarter of today's field," explains Norbert Nowaczyk. "The actual polarity changes lasted only 250 years. In terms of geological time scales, that is very fast." During this period, the field was even weaker, with only 5% of today's field strength. As a consequence, Earth nearly completely lost its protection shield against hard cosmic rays, leading to a significantly increased radiation exposure.
This is documented by peaks of radioactive beryllium (10Be) in ice cores from this time, recovered from the Greenland ice sheet. 10Be as well as radioactive carbon (14C) is caused by the collision of high-energy protons from space with atoms of the atmosphere.
The Laschamp event
The polarity reversal now found with the magnetisation of Black Sea sediments has already been known for 45 years. It was first discovered after the analysis of the magnetisation of several lava flows near the village Laschamp near Clermont-Ferrand in the Massif Central, which differed significantly from today's direction of the geomagnetic field. Since then, this geomagnetic feature is known as the 'Laschamp event'. However, the data of the Massif Central represent only some point readings of the geomagnetic field during the last ice age, whereas the new data from the Black Sea give a complete image of geomagnetic field variability at a high temporal resolution.
Abrupt climate changes and a super volcano
Besides giving evidence for a geomagnetic field reversal 41,000 years ago, the geoscientists from Potsdam discovered numerous abrupt climate changes during the last ice age in the analysed cores from the Black Sea, as it was already known from the Greenland ice cores. This ultimately allowed a high precision synchronisation of the two data records from the Black Sea and Greenland.
The largest volcanic eruption on the Northern hemisphere in the past 100,000 years, namely the eruption of the super volcano 39,400 years ago in the area of today's Phlegraean Fields near Naples, Italy, is also documented within the studied sediments from the Black Sea. The ashes of this eruption, during which about 350 cubic kilometers of rock and lava were ejected, were distributed over the entire eastern Mediterranean and up to central Russia.
These three extreme scenarios, a short and fast reversal of Earth's magnetic field, short-term climate variability of the last ice age and the volcanic eruption in Italy, have been investigated for the first time in a single geological archive and placed in precise chronological order.ScienceDaily (Oct. 16, 2012) — Some 41,000 years ago, a complete and rapid... more
Perhaps you thought that the whole “planet isn’t warming” meme was killed by this summer’s bombshell Koch-funded study. After all, it found ”global warming is real,” “on the high end” and “essentially all” due to carbon pollution.
Sadly, denial springs eternal. Long-debunked denier David Rose has an article in the Daily Mail, “Global warming stopped 16 years ago, reveals Met Office report quietly released … and here is the chart to prove it.”
The piece is so misleading, even the UK Met Office felt a need to instantly debunk it with a blog post that included this chart.
UK Met Office graph showing years ranked in order of global temperature.
Since Rose managed to find one misleading chart to push his myth, I thought I would dig up ten serious ones that show the reverse, including the top chart from Skeptical Science, the great Australian blog, which is derived from the data in the Koch-funded study.
Note: “Skeptics” is an Aussie word for denier or disinformer. The British have their own words — Rose or Mail:
•David Rose destroys his credibility and the Daily Mail’s with error-riddled climate science reporting
•Daily Mail Slammed for Ignoring Scientific Truth We’re Still Warming and Human Emissions Will Dwarf Any Solar Changes
So one has to assume going in that any climate piece in the Mail with Rose’s name on it is somewhere between misinformation and disinformation. The latest piece tends toward the latter. Heck, even Judith Curry complains she was misquoted, as Media Matters notes.
The Met Office, part of the UK Defence Ministry, explained, it’s absurd to look at a cherry-picked “trend from August 1997 (in the middle of an exceptionally strong El Nino) to August 2012 (coming at the tail end of a double-dip La Nina)”:
As we’ve stressed before, choosing a starting or end point on short-term scales can be very misleading. Climate change can only be detected from multi-decadal timescales due to the inherent variability in the climate system. If you use a longer period from HadCRUT4 the trend looks very different. For example, 1979 to 2011 shows 0.16°C/decade (or 0.15°C/decade in the NCDC dataset, 0.16°C/decade in GISS). Looking at successive decades over this period, each decade was warmer than the previous – so the 1990s were warmer than the 1980s, and the 2000s were warmer than both. Eight of the top ten warmest years have occurred in the last decade.
Over the last 140 years global surface temperatures have risen by about 0.8ºC. However, within this record there have been several periods lasting a decade or more during which temperatures have risen very slowly or cooled. The current period of reduced warming is not unprecedented and 15 year long periods are not unusual.
The warming trend is clear in a chart from an earlier Met Office post “Noughties confirmed as the warmest decade on record“:
More at the linkPerhaps you thought that the whole “planet isn’t warming” meme was... more
The countervailing effects don't cancel each other out. They're both signs of the changes we are bringing to the planet.
In the seas to our north, sea ice is melting at a perilous pace. This year crushed earlier records for the lowest sea-ice extent ever recorded in the Arctic. Some scientists predict that in four years, Arctic sea ice may collapse entirely during the summer months.
It turns out that the northern pole is not the only one setting records with unusual ice patterns. But to the south, the story is different: record-setting sea-ice extent. That is to say: While the ice to the north is melting away, the ice to the south is growing, extended over 19.44 million square kilometers this year, breaking the previous record (set in 2006) of 19.39 million square kilometers..
Now, lest you get all, "Phew. So glad this who global warming thing is being balanced out," let me tell you plainly: That is not how it works. These are not counteracting phenomena that somehow cancel each other out. Both of these sea-ice trends are the result of changes in our planet's climate, but the effects are different because our hemispheres work in different ways.
To begin to understand this, look north first. The ice there is melting for a pretty straightforward reason: It is getting warmer. As the sea ice melts, the dark oceans absorb more of the suns rays than the bright ice (which reflected them), and the process accelerates.
The south has a more complicated story, with several converging reasons for the ice accretion. The first reason is our depleted ozone layer, which has brought cooler winds and stormier weather. Scientists think that the hole in the ozone has brought temperatures in the stratosphere over Antarctica (about 6 to 37 miles overhead) down by 2 to 6 degrees Celsius. The increased winds push the sea ice around, opening up gaps of water called polynyas where more ice develops rapidly.
Another possible contributing force is an increasingly temperature-stratified ocean. As NASA explained in 2009:
Changes in ocean circulation may also play a role. Jinlun Zhang, an oceanographer at the University of Washington, has pieced together a complex computer model that helps explain why Antarctic sea ice is expanding even with signs that ocean and air temperatures are on the rise. The key is that warming temperatures can lead to more stratified ocean layers.
In the Southern Ocean, there's a layer of cold water near the surface and a layer of warmer water below. Normally, convection causes the two layers to mix and exchange water, a process that brings heat from the lower layers to the surface layer and ultimately helps keep sea ice expansion in check. This transfer of heat is the primary reason that first-year ice in the Antarctic is much thinner than in the Arctic.
But if global air temperatures warm, the model indicates that the amount of rain and snowfall could increase, and surface waters could freshen. Since fresh water is less dense and less apt to mix with the heavier, saltier, and warmer water below, the layer at the ocean's surface could become more stratified and mix less. This, in turn, would reduce the amount of heat flowing upward, allowing surface ice to expand.
One last thing to note: Besides that the polar effects are moving in opposite directions (polar opposites, get it?), the magnitude of the changes are not even close.
The minimum extent of Arctic sea ice is declining by an average of some 91,600 square kilometers per year. Antarctica, in contrast, is gaining ice by about 17,000 square kilometers a year. But even if the pace *were* the same, where would that leave us?
No amount of ice at the South Pole is going to get us out of the jam we're in.The countervailing effects don't cancel each other out. They're both signs... more
WASHINGTON (AP) — The ice goes on seemingly forever in a white pancake-flat landscape, stretching farther than ever before. And yet in this confounding region of the world, that spreading ice may be a cockeyed signal of man-made climate change, scientists say.
This is Antarctica, the polar opposite of the Arctic.
While the North Pole has been losing sea ice over the years, the water nearest the South Pole has been gaining it. Antarctic sea ice hit a record 7.51 million square miles in September. That happened just days after reports of the biggest loss of Arctic sea ice on record.
Climate change skeptics have seized on the Antarctic ice to argue that the globe isn't warming and that scientists are ignoring the southern continent because it's not convenient. But scientists say the skeptics are misinterpreting what's happening and why.
Shifts in wind patterns and the giant ozone hole over the Antarctic this time of year — both related to human activity — are probably behind the increase in ice, experts say. This subtle growth in winter sea ice since scientists began measuring it in 1979 was initially surprising, they say, but makes sense the more it is studied.
"A warming world can have complex and sometimes surprising consequences," researcher Ted Maksym said this week from an Australian research vessel surrounded by Antarctic sea ice. He is with the Woods Hole Oceanographic Institution in Massachusetts.
Many experts agree. Ted Scambos of the National Snow and Ice Data Center in Colorado adds: "It sounds counterintuitive, but the Antarctic is part of the warming as well."
And on a third continent, David Vaughan of the British Antarctic Survey says that yes, what's happening in Antarctica bears the fingerprints of man-made climate change.
"Scientifically the change is nowhere near as substantial as what we see in the Arctic," says NASA chief scientist Waleed Abdalati, an ice expert. "But that doesn't mean we shouldn't be paying attention to it and shouldn't be talking about it."
Sea ice is always melting near one pole while growing around the other. But the overall trend year to year is dramatically less ice in the Arctic and slightly more in the Antarctic.
It's most noticeable in September, when northern ice is at its lowest and southern ice at its highest. For over 30 years, the Arctic in September has been losing an average of 5.7 square miles of sea ice for every square mile gained in Antarctica.
Loss of sea ice in the Arctic can affect people in the Northern Hemisphere, causing such things as a higher risk of extreme weather in the U.S. through changes to the jet stream, scientists say. Antarctica's weather peculiarities, on the other hand, don't have much effect on civilization.
At well past midnight in Antarctica, where it's about 3 degrees, Maksym describes in a rare ship-to-shore telephone call from the R.V. Aurora Australis what this extra ice means in terms of climate change. And what it's like to be out studying it for two months, with the nearest city 1,500 miles away.
"It's only you and the penguins," he says. "It's really a strikingly beautiful and stark landscape. Sometimes it's even an eerie kind of landscape."
While the Arctic is open ocean encircled by land, the Antarctic — about 1.5 times the size of the U.S. — is land circled by ocean, leaving more room for sea ice to spread. That geography makes a dramatic difference in the two polar climates.
The Arctic ice responds more directly to warmth. In the Antarctic, the main driver is wind, Maksym and other scientists say. Changes in the strength and motion of winds are now pushing the ice farther north, extending its reach.
Those changes in wind are tied in a complicated way to climate change from greenhouse gases, Maksym and Scambos say. Climate change has created essentially a wall of wind that keeps cool weather bottled up in Antarctica, NASA's Abdalati says.
And the wind works in combination with the ozone hole, the huge gap in Earth's protective ozone layer that usually appears over the South Pole. It's bigger than North America.
It's caused by man-made pollutants chlorine and bromine, which are different from the fossil fuel emissions that cause global warming. The hole makes Antarctica even cooler this time of year because the ozone layer usually absorbs solar radiation, working like a blanket to keep the Earth warm.
And that cooling effect makes the winds near the ground stronger and steadier, pushing the ice outward, Scambos says.
University of Colorado researcher Katherine Leonard, who is on board the ship with Maksym, says in an email that the Antarctic sea ice is also getting snowier because climate change has allowed the air to carry more moisture.
Winter sea ice has grown by about 1 percent a decade in Antarctica. If that sounds small, it's because it's an average. Because the continent is so large, it's a little like lumping together the temperatures of the Maine and California coasts, Vaughan says.
Mark Serreze, director of the snow and ice data center, says computer models have long predicted that Antarctica would not respond as quickly to global warming as other places. Since 1960, the Arctic has warmed the most of the world's regions, and Antarctica has warmed the least, according to NASA data.
Scientists on the cruise with Maksym are spending eight to 12 hours a day on the ice bundled up against the fierce wind with boots that look like Bugs Bunny's feet. It's dangerous work. Cracks in sea ice can form at any time. Just the other day a sudden fissure stranded a team of scientists until an inflatable bridge rescued them.
"It's a treacherous landscape," Vaughan says.http://news.yahoo.com/experts-global-warming-means-more-antarctic-ice-194009890.html... more