Artist's rendering of NASA's Orbiting Carbon Observatory (OCO)-2, one of five new NASA Earth science missions set to launch in 2014, and one of three managed by JPL.
Image Credit:
NASA-JPL/Caltech
On February 24, 2009, the launch of the Orbiting Carbon Observatory (OCO) mission — designed to study the global fate of carbon dioxide — resulted in failure. Shortly after launch, the rocket nose didn’t separate as expected, and the satellite could not be released.
But now, a carbon copy of the original mission, called OCO-2 is slated to launch on July 1, 2014.
The original failure ended in “heartbreak. The entire mission was lost. We didn’t even have one problem to solve,” said OCO-2 Project Manager Ralph Basilio in a press conference earlier today. “On behalf of the entire team that worked on the original OCO mission, we’re excited about this opportunity … to finally be able to complete some unfinished business.”
The motivation for the mission is simple: in the last few hundred years, human beings have played a large role in the planet-wide balancing act called the carbon cycle. Our activities, such as fossil fuel burning and deforestation are pushing the cycle out of its natural balance, adding more carbon dioxide to the atmosphere.
“There’s a steady increase in atmospheric carbon dioxide concentrations over time,” said OCO-2 Project Scientist Mike Gunson. “But at the same time, we can see that this has an annual cycle of dropping every summer, in this case in the northern hemisphere, as the forests and plants grow. And this is the Earth breathing.”
Time series of atmospheric carbon dioxide over the northern hemisphere retrieved from the Sciamachy instrument on Envisat and the TANSO instrument on Japan’s GOSAT. The different colours represent different methods of extracting carbon dioxide measurements from the measured spectra of reflected solar radiation. Credit: University Bremen/ESA
Carbon dioxide is both one of the best-measured greenhouse gases and least-measured. Half of the emissions in the atmosphere become largely distributed around the globe in a matter of months. But the other half of the emissions — the half that is being absorbed through natural processes into the land or the ocean — is not evenly distributed.
To understand carbon dioxide absorption, we need a high-resolution global map.
This is where the launch failure of OCO proved to be a blessing in disguise. It gave OCO-2 scientists a chance to work with project managers of the Japanese Greenhouse Gases Observing Satellite (GOSAT), which successfully launched in 2009. The unexpected collaboration allowed them to stumble upon a hidden surprise.
“A couple of my colleagues made what I think is a fantastic discovery,” said Gunson. They discovered fluorescent light from vegetation.
As plants absorb sunlight, some of the light is dissipated as heat, while some is re-emitted at longer wavelengths as fluorescence. Although scientists have measured fluorescence in laboratory settings and ground-based experiments, they have never done so from space.
Measuring the fluorescent glow proves to be a challenge because the tiny signal is overpowered by reflected sunlight. Researchers found that by tuning their GOSAT spectrometer — an instrument that can measure light across the electromagnetic spectrum — to look at very narrow channels, they could see parts of the spectrum where there was fluorescence but less reflect sunlight.
This surprise will give OCO-2 an unexpected global view from space, shedding new light on the productivity of vegetation on land. It will provide a regional map of absorbed carbon dioxide, helping scientists to estimate photosynthesis rates over vast scales and better understand the second half of the carbon cycle.
Ralph Basilio, OCO-2 project manager with NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, left, and Mike Gunson, OCO-2 project scientist at JPL, discuss the Orbiting Carbon Observatory-2 (OCO-2), NASA’s first spacecraft dedicated to studying carbon dioxide, during a press briefing, Thursday, June 12, 2014, at NASA Headquarters in Washington. Credit: NASA.
“The OCO-2 satellite has one instrument: a three-channel grating spectrometer,” said OCO-2 Program Executive Betsy Edwards. “But with this one instrument we’re going to collect hundreds of thousands of measurements each day, which will then provide a global description of carbon dioxide in the atmosphere. It’s going to be an unprecedented level of coverage and resolution, something we have not seen before with previous spacecraft.”
OCO-2 will result in nearly 100 times more observations of both carbon dioxide and fluorescence than GOSAT. It will launch from Vandenberg Air Force Base in California at 2:56 a.m. on July 1.
“Climate change is the challenge of our generation,” said Edwards. “NASA is particularly ready to … provide information, on documenting and understanding what these changes are on the climate, in predicting the impact of these changes to the Earth, and in sharing all of this information that we gather for the benefit of society.”
Screenshot from the video showing the variations in the amount of CO2 in Earth atmosphere for the last 800,000 years.
I’m always amazed by the power of data visualization. In this case a video shrinks the rising levels of carbon dioxide over the course of 800,000 years to just under two minutes.
The motivation is simple: April set a carbon dioxide milestone by averaging 400 parts per million for the entire month. That’s uncharted territory over the course of human history.
The levels of carbon dioxide in the atmosphere are monitored from a site atop Hawaii’s Mauna Loa volcano, where they have been measured continuously since 1958. Previous to this date scientists measure ice cores, which contain air bubbles and therefore snapshots of carbon dioxide levels.
Prior to the Industrial Revolution CO2 levels stayed roughly around 280 ppm. But then with the kickstart of carbon emissions, levels were driven exponentially higher. They soared past 350 ppm — the level scientist James Hansen said was the safe upper limit of CO2 — in October 1989.
The first measurement in excess of 400 ppm was made on May 9, 2013. This year, the level rose above that mark two months earlier, and has remained above 400 ppm steadily since the beginning of April. Levels will peak in May and then drop back down throughout the summer months as trees and plants soak up some CO2.
Once the northern hemisphere spins into fall, the instrument on Mauna Loa will again read higher CO2 levels. Next year will probably see an even earlier onset of levels above 400 ppm. It likely won’t be long before levels never drop lower than 400 ppm, even throughout the summer months.
Also, today the U.S. Global Change Research Program released a report that has been five years in the making, providing an overview of observed and projected climate change. It’s a lengthy document, but you can see an overview here. In sum, the report shows how the world is already experiencing the effects of climate change and the impacts are playing out before our eyes.
“We’ve seen a lot in the last five years,” said Andrew Rosenberg of the Union of Concerned Scientists, one of the lead authors on the report’s oceans chapter, in a press release from The Daily Climate. “So what we’ve tried to do is be quite comprehensive on what our observations have been, as opposed to just modeling projections.”
“Five years ago, ocean acidification and species movement was already happening, but the observational record wasn’t as clear,” Rosenberg said. “Now it really is quite clear. It’s not theory-based or model-based.”
Global temperatures measured by decades since the 1880’s. The period from 2001-2012 was the warmest on record globally. Every year was warmer than the 1990s average. Credit: U.S. Global Change Research Program.
This report is unique in that it not only includes data from scientists, but also has input from local groups and industries facing climate impacts. Corn producers in Iowa, oyster growers in Washington, and maple syrup producers in Vermont are all experiencing climate-related issues. So, too, are coastal planners in Florida, water managers in the Southwest, and Native Peoples on tribal lands from Louisiana to Alaska.
Human beings are already being impacted by climate change.
One of the most striking features of the climate change ‘debate’ is that it’s no longer a debate. Climate scientists around the world agree that climate change is very real — the Earth is warming up and we are the cause.
Yet while there is consensus even among the most reserved climate scientists, a portion of the public persistently disagrees. A recent Pew Research Center — an organization that provides information on demographic trends across the U.S. and the world — survey found that roughly four-in-ten Americans see climate change as a global threat. Climate scientists are racking their brains in an attempt to find out why.
Yale law professor Dan Kahan has done extensive research which reveals how our deep-rooted cultural dispositions might interfere with our perceptions of reality.
Why We Resist Climate Change
In 2010 Kahan led a study, “Cultural Cognition of Scientific Consensus,” which found that individuals tend to weigh evidence and credit experts differently based on cultural considerations. Psychological mechanisms allow individuals to selectively credit or dismiss evidence and experts, depending on whether the views presented match the dominant view of their group.
“There is an interdependence between people’s prior beliefs about risk and their exposure to and understanding of information,” Kahan told Universe Today. “People are motivated to search out information in a biased way. They look more for information that is consistent with their views than for information that is going to refute their views.”
Kahan’s study was administered online to 1,500 U.S. adults. Preliminary analyses wanted to determine if the public thought there was a scientific consensus regarding climate change and if there was a scientific consensus regarding human activity as the cause.
A majority — 55 percent — of the subjects reported their opinion that most scientists agree that global temperatures are rising, 12 percent believed most scientists do not find that global temperatures are rising, and 33 percent believed that scientists are divided on the topic. On whether or not human activity is the cause, 45 percent believed scientists agree that human activity is the cause, 15 percent believed scientists don’t think human activity is the cause, and 40 percent believed scientists are divided on the topic.
The public is generally not in a position to investigate the data for themselves or even read a scientific paper full of unfamiliar acronyms, plots and equations. Instead they turn to experts for assistance. Often times in determining who is credible, individuals will trust those who share similar world views and personal values. They tend to seek information congenial to their cultural predispositions.
For Kahan’s first experiment, the subjects read the biographical information of an expert scientist. They had to decide whether he was credible, having earned a Ph.D. from an elite university and now serving as a faculty member of another elite university. Those who listed themselves as hierarchical — believing in stratified social roles (generally conservatives) — were more likely to find the expert scientist credible, while those who listed themselves as communitarian — expecting individuals to secure their own well-being (generally liberals) — were more likely to find the expert scientist not credible.
These fictional individuals were identified as credible or not based on their biographies only. Credit: Kahan et al. 2010
However, a second experiment showed the subjects not only the resume of the expert scientist but his position as well. Half the subjects were shown evidence that the expert believed in climate change, placing us at a high risk, while the other half of the subjects were shown evidence that the expert didn’t believe in climate change, placing us at a low risk.
The position imputed by the expert scientist dramatically affected the responses of the subjects. When the expert scientist supported a high risk position, 23 percent of the hierarchs and 88 percent of the communitarians found him credible. In contrast, when the expert scientist supported a low risk position, 86 percent of the hierarchs and 47 percent of the communitarians found him credible.
Whether the expert scientist was considered credible was highly associated with whether he took the position dominant in the subject’s cultural group. The subjects “have dispositions that are connected to their values that then will affect how they make sense of information,” Kahan said.
The percentage of subjects who found the author credible depending on whether he supported a high risk (climate change is real) or low risk (climate change is not real) position. Credit: Kahan et al. 2010
At the end of the day the conclusion is simple: we’re human. And this leads us to take the path of least resistance: we choose to believe in what those around us believe.
So it’s not that people aren’t sufficiently rational. “They’re too rational,” Kahan said. “They’re too good at extracting from the information you’re giving them, which sends the message that tells them what position they should take given the kind of person they are.”
Moving Forward
Kahan’s study shows that scientific consensus alone will not sway the public. The public will remain polarized despite efforts to increase trust in scientists or simply awareness of scientific research. Instead the key is to use science communication strategies, which reduce the likelihood the public will find climate change threatening.
In a more recent study, published in Nature, Kahan analyzed two techniques of science communication that may help break the connection between cultural predispositions and the evaluation of information.
The first technique is to frame the information in a manner that doesn’t threaten people’s values. In this study, Kahan and his colleagues asked participants to once again assess the credibility of climate change. But before doing so the subjects had to read an article.
One article was a study suggesting that carbon dissipates from the atmosphere much slower than scientists had previously thought. As a result, if we stopped producing carbon today, there would still be catastrophic effects: rising sea level, drought, hurricanes, etc. Another article (shown to a different group) gave information on geo-engineering or nuclear power — potential technological advances that may help reduce the effects of climate change. A final control group read an unrelated article on traffic lights.
Logically all of these articles had nothing to do with whether climate change is valid. But psychologically these articles did determine the meaning that people attached to the evidence of climate change. In all cases the hierarchs were less likely than the communitarians to say climate change is valid. But the gap was 29 percent smaller among the group that was first exposed to geo-engineering than the group that was exposed to regulating carbon.
“The evidence of whether there is a problem doesn’t depend on what you’re going to do about it,” Kahan said. “But psychologically it can make a difference.”
People tend to resist scientific evidence that may lead to restrictions on their personal activities, or evidence that threatens them as individuals But if they are presented with information in a way that upholds their identities, they react with an open mind.
The second technique is to ensure that climate change is vouched for by a diverse set of experts. If a particular group is able to identify with that expert, then that group will be more open-minded in addressing the study. This will help reduce the initial polarization between hierarchs and communitarians.
Kahan argues that science “needs better marketing.” It needs to combine climate change with meanings that are affirming rather than threatening to people. When groups can identify with the expert, or are presented with possible solutions to climate change, the individuals in that group will stop attaching the issues to identity.
According to Kahan, in order to move forward, science communication needs to change the narrative. It needs to mitigate the connection between climate change and the individual. In order for there to be a public consensus on climate change it has to be presented in a less threatening manner.
This doesn’t mean that science communication has to avoid the nasty truth about climate change in order to finally reach a public consensus. Instead it has to spin climate change in a positive way — a way that is less threatening to the individual.
Science communication has to focus the public’s attention on what so many individuals value: efficiency, not being wasteful, innovation and moving forward. Only then will the public reach a consensus where there is now only polarization.
Chart of the temperature anomalies for 1950-2013, also showing the phase of the El Niñ0-La Niña cycle. (Image Credit: NASA/GSFC/Earth Observatory, NASA/GISS)
The latest statistics are in from 2013 and both NASA’s and NOAA’s measurements of global temperatures show Earth continued to experience temperatures warmer than those measured several decades ago.
NASA scientists say 2013 tied with 2009 and 2006 for the seventh warmest year since 1880, continuing a long-term trend of rising global temperatures, while NOAA – which uses a different method of analyzing temperature data – said that 2013 tied with 2003 as 4th-warmest year globally since 1880.
“The long-term trends are very clear, and they’re not going to disappear,” said climatologist Gavin Schmidt from NASA’s Goddard Institute for Space Studies (GISS). “It isn’t an error in our calculations.”
Land and ocean global temperatures in 2013 from both NASA and NOAA. Via NASA.
NASA data shows that since 1950, average temperatures have increased 1.1°F to an average of 58.3° in 2013.
NOAA data shows the average temperature across global land and ocean surfaces was 1.12 degrees above the 20th-century average. This is the 37th consecutive year that the annual temperature was above the long-term average.
This coincides with another recent study that showed the so-called “pause” in global warming is not happening, and that the temperatures over the past 15 years are still on the rise.
Both NASA and NOAA scientists say the increase in greenhouse gas levels continue to drive the temperature increase.
Additionally, with the exception of 1998, the 10 warmest years in the 134-year record all have occurred since 2000, with 2010 and 2005 ranking as the warmest years on record.
NASA says the average temperature in 2013 was 58.3 degrees Fahrenheit (14.6 Celsius), which is 1.1 F (0.6 C) warmer than the mid-20th century baseline. The average global temperature has risen about 1.4 degrees F (0.8 C) since 1880, according to the new analysis. Exact rankings for individual years are sensitive to data inputs and analysis methods.
“Long-term trends in surface temperatures are unusual and 2013 adds to the evidence for ongoing climate change,” GISS climatologist Gavin Schmidt said. “While one year or one season can be affected by random weather events, this analysis shows the necessity for continued, long-term monitoring.”
Scientists emphasize that weather patterns always will cause fluctuations in average temperatures from year to year, but the continued increases in greenhouse gas levels in Earth’s atmosphere are driving a long-term rise in global temperatures. Each successive year will not necessarily be warmer than the year before, but with the current level of greenhouse gas emissions, scientists expect each successive decade to be warmer than the previous.
More from NASA:
Carbon dioxide is a greenhouse gas that traps heat and plays a major role in controlling changes to Earth’s climate. It occurs naturally and also is emitted by the burning of fossil fuels for energy. Driven by increasing man-made emissions, the level of carbon dioxide in Earth’s atmosphere presently is higher than at any time in the last 800,000 years.
The carbon dioxide level in the atmosphere was about 285 parts per million in 1880, the first year in the GISS temperature record. By 1960, the atmospheric carbon dioxide concentration, measured at the National Oceanic and Atmospheric Administration’s (NOAA) Mauna Loa Observatory in Hawaii, was about 315 parts per million. This measurement peaked last year at more than 400 parts per million.
While the world experienced relatively warm temperatures in 2013, the continental United States experienced the 42nd warmest year on record, according to GISS analysis. For some other countries, such as Australia, 2013 was the hottest year on record.
The temperature analysis produced at GISS is compiled from weather data from more than 1,000 meteorological stations around the world, satellite observations of sea-surface temperature, and Antarctic research station measurements, taking into account station history and urban heat island effects. Software is used to calculate the difference between surface temperature in a given month and the average temperature for the same place from 1951 to 1980. This three-decade period functions as a baseline for the analysis. It has been 38 years since the recording of a year of cooler than average temperatures.
The GISS temperature record is one of several global temperature analyses, along with those produced by the Met Office Hadley Centre in the United Kingdom and NOAA’s National Climatic Data Center in Asheville, N.C. These three primary records use slightly different methods, but overall, their trends show close agreement.
You can read NASA’s press release here, and NOAA’s here. Here is a link to a presentation of the data released today from Gavin Schmidt of NASA and Tom Karl, director of NOAA’s Climatic Data Center.
New topography map of Antarctica by the British Antarctic Survey's Bedmap2 (NASA/GSFC)
Although it sits isolated at the “bottom of the world” Antarctica is one of the most influential continents on Earth, affecting weather, climate, and ocean current patterns over the entire planet. But Antarctica is also one of the most enigmatic landmasses too, incredibly remote, extremely harsh, and covered by a layer of ice over 2 km thick. And as Earth’s global temperature continues to climb steadily higher, the future of ice in Antarctica — a continent half again as large as the contiguous United States — is a big concern for scientists… but in order to know exactly how its ice will behave to changing conditions, they need to know what’s under it.
This is where the British Antarctic Survey — using data gathered by NASA’s ICESat and Operation IceBridge missions — comes in, giving us a better view of what lies beneath the southern continent’s frozen veil.
A new dataset called Bedmap2 gives a clearer picture of Antarctica from the ice surface down to the bedrock below. Bedmap2 is a significant improvement on the previous collection of Antarctic data — known as Bedmap — that was produced more than 10 years ago. The product was a result of work led by the British Antarctic Survey, where researchers compiled decades worth of geophysical measurements, such as surface elevation measurements from NASA’s Ice, Cloud and Land Elevation Satellite (ICESat) and ice thickness data collected by Operation IceBridge.
Bedmap2, like the original Bedmap, is a collection of three datasets—surface elevation, ice thickness and bedrock topography. Both Bedmap and Bedmap2 are laid out as grids covering the entire continent, but with a tighter grid spacing Bedmap2 includes many surface and sub-ice features too small to be seen in the previous dataset. Additionally, the extensive use of GPS data in more recent surveys improves the precision of the new dataset.
Improvements in resolution, coverage and precision will lead to more accurate calculations of ice volume and potential contribution to sea level rise.
Ice sheet researchers use computer models to simulate how ice sheets will respond to changes in ocean and air temperatures. An advantage of these simulations is that they allow testing of many different climate scenarios, but the models are limited by how accurate the data on ice volume and sub-ice terrain are.
Only the tips of many of Antarctica’s mountains are visible above thousands of feet of ice. (Oct. 2012 IceBridge photo. Credit: NASA / Christy Hansen)
“In order to accurately simulate the dynamic response of ice sheets to changing environmental conditions, such as temperature and snow accumulation, we need to know the shape and structure of the bedrock below the ice sheets in great detail,” said Michael Studinger, IceBridge project scientist at NASA Goddard.
Knowing what the bedrock looks like is important for ice sheet modeling because features in the bed control the ice’s shape and affect how it moves. Ice will flow faster on a downhill slope, while an uphill slope or bumpy terrain can slow an ice sheet down or even hold it in place temporarily. “The shape of the bed is the most important unknown, and affect how ice can flow,” said Nowicki. “You can influence how honey spreads on your plate, by simply varying how you hold your plate.” The vastly improved bedrock data included in Bedmap2 should provide the level of detail needed for models to be realistic.
Bedmap2 data of Antarctica’s bedrock. Verical elevation has been exaggerated by 17x. (NASA/GSFC)
“It will be an important resource for the next generation of ice sheet modelers, physical oceanographers and structural geologists,” said Peter Fretwell, BAS scientist and lead author.
The BAS’ work was published recently in the journal The Cryosphere. Read more on the original release by George Hale here.
Saunders Island and Wolstenholme Fjord with Kap Atholl in the background photographed during a NASA IceBridge flight. (NASA/Michael Studinger)
It’s quite a long way from Mars, but I can’t help but be reminded of the Red Planet’s ice-covered north pole when looking at this photo taken by Michael Studinger earlier this month, during a recent IceBridge survey flight over Greenland.
Called Saunders Island (also Appat Island) the 82-square-mile frozen slab of rock rises from the sea off the coast of northwestern Greenland, one of many islands within the Wolstenholme (Uummannaq) Fjord on the shore of Baffin Bay. Operation IceBridge, a six-year aerial survey of the changing ice coverage at our planet’s poles, is run by NASA to provide valuable ground-level information to supplement satellite data.
To me, the shape of the island’s steep rock faces and rugged inlets slice into its interior bear a striking resemblance to Mars’ ice cap.
Mars’ north polar ice cap
While Mars’ ice cap is shaped by very different processes — and obviously much bigger — you might see the connection too!
But rather than dark Martian dunes, sea ice can be seen surrounding the islands in varying thicknesses in the IceBridge photo above. Sea ice coverage in the fjord ranges from thicker, white ice in the background to thinner “grease” ice and leads with dark, open ocean water in the foreground.
The IceBridge P-3B airborne laboratory in a hangar at Wallops Flight Facility (NASA/George Hale)
As the amount of darker, ice-free water surfaces increase over the course of the year due to rising global temperatures, the more heat from solar radiation is collected in the ocean — thus speeding up the process of seasonal sea ice loss and overall Arctic warming.
Read more about the IceBridge mission here, and see a collection of more photos from this season’s flights here.
NASA’s Operation IceBridge images Earth’s polar ice in unprecedented detail to better understand processes that connect the polar regions with the global climate system. IceBridge utilizes a highly specialized fleet of research aircraft and the most sophisticated suite of innovative science instruments ever assembled to characterize annual changes in thickness of sea ice, glaciers, and ice sheets. In addition, IceBridge collects critical data used to predict the response of earth’s polar ice to climate change and resulting sea-level rise.
This map represents global temperature anomalies averaged from 2008 through 2012. Credit: NASA Goddard Institute for Space Studies/NASA Goddard's Scientific Visualization Studio.
This week, scientists at NASA released their global climate analysis for 2012 which revealed that Earth continues to experience warmer temperatures than several decades ago. The past year was the ninth warmest year on record since 1880, continuing what appears to be a long-term global trend of rising temperatures. The ten warmest years in the 132-year record have all occurred since 1998, and the last year that was cooler than average was 1976. The hottest years on record were 2010 and 2005.
The analysis was done by NASA’s Goddard Institute for Space Studies (GISS) which monitors global surface temperatures on an ongoing basis, comparing temperatures around the globe to the average global temperature from the mid-20th century.
In 2012, the average temperature was about 14.6 degrees Celsius (58.3 degrees Fahrenheit). This is .55 degrees C (1.0 degree F) warmer than the mid-20th century baseline, with the global average temperature having risen about 0.8 degrees C (1.4 degrees F) since 1880. The majority of that change has occurred in the past forty years.
Additionally, last week the US National Climatic Data Center (NCDC) released their latest climate report from 2012 and found that it was the warmest year ever recorded in the contiguous United States. The average temperature for the contiguous United States for 2012 was 13 degrees C (55.3 degrees F) which was 3.2°F above the 20th century average.
The map depicts temperature anomalies, or changes, by region in 2012; while the line plot above shows yearly temperature anomalies from 1880 to 2011 as recorded by NASA GISS, the National Oceanic and Atmospheric Administration (NOAA) National Climatic Data Center, the Japanese Meteorological Agency, and the Met Office Hadley Centre in the United Kingdom. NASA Goddard Institute for Space Studies.
The data was gathered by NASA GISS, the National Oceanic and Atmospheric Administration (NOAA) National Climatic Data Center, the Japanese Meteorological Agency, and the Met Office Hadley Centre in the United Kingdom. All four institutions tally temperature data from stations around the world and make independent judgments about whether the year was warm or cool compared to other years. Though there are minor variations from year to year, all four records show peaks and valleys in sync with each other. All show rapid warming in the past few decades, and all show the last decade as the warmest.
Scientists emphasize that weather patterns cause fluctuations in average temperatures from year to year, but the continued increase in greenhouse gas levels in the atmosphere assures that there will be a long-term rise in global temperatures. Each individual year will not necessarily be warmer than the previous year, but scientists expect each decade to be warmer than the previous decade.
“One more year of numbers isn’t in itself significant,” GISS climatologist Gavin Schmidt said. “What matters is this decade is warmer than the last decade, and that decade was warmer than the decade before. The planet is warming. The reason it’s warming is because we are pumping increasing amounts of carbon dioxide into the atmosphere.”
See an interactive global temperature map from New Scientist.
Carbon dioxide traps heat and largely controls Earth’s climate. It occurs naturally but is also released by the burning of fossil fuels for energy. The level of carbon dioxide in Earth’s atmosphere has been rising consistently for decades, largely driven by increasing man-made emissions. The carbon dioxide level in the atmosphere was about 285 parts per million in 1880, the first year of the GISS temperature record. By 1960, the atmospheric carbon dioxide concentration, measured at NOAA’s Mauna Loa Observatory, was about 315 parts per million. Today, that measurement exceeds 390 parts per million.
The continental U.S. endured its warmest year on record by far, according to NOAA, the official keeper of U.S. weather records. NOAA also announced that global temperatures were 10th warmest on record by their analysis methods.
“The U.S. temperatures in the summer of 2012 are an example of a new trend of outlying seasonal extremes that are warmer than the hottest seasonal temperatures of the mid-20th century,” NASA GISS director James E. Hansen said. “The climate dice are now loaded. Some seasons still will be cooler than the long-term average, but the perceptive person should notice that the frequency of unusually warm extremes is increasing. It is the extremes that have the most impact on people and other life on the planet.”
Sea ice swirls in ocean currents off the coast of Greenland (NASA/GSFC)
Spooky spectral swirls of last season’s sea ice drift in currents off the coast of eastern Greenland in this image from NASA’s Aqua satellite, acquired on October 17. Although sea ice in the Arctic will start forming again after September’s record low measurements, these ghostly wisps are likely made up of already-existing ice that has migrated south.
As global temperatures rise — both over land and in the ocean — thinner sea ice builds up during the Arctic winter and thus more of it melts during the summer, a pattern that will eventually lead to an ice-free Arctic if trends continue. The past several years saw sea ice in the Arctic below the 1979-2000 average, with this past September displaying the lowest volumes yet recorded.
The graph below, made from data modeled by the Polar Science Center at the University of Washington, show the chilling — or, perhaps, not-so-chilling — results of this century’s recent observations.
Along Greenland’s east coast, the Fram Strait serves as an expressway for sea ice moving out of the Arctic Ocean. The movement of ice through the strait used to be offset by the growth of ice in the Beaufort Gyre.
Until the late 1990s, ice would persist in the gyre for years, growing thicker and more resistant to melt. Since the start of the twenty-first century, however, ice has been less likely to survive its trip through the southern part of the Beaufort Gyre. As a result, less Arctic sea ice has been able to pile up and form multi-year ice.
Thin, free-drifting ice — as seen above — moves very easily with winds and currents.
Aqua is a NASA Earth Science satellite mission named for the large amount of information that the mission is collecting about the Earth’s water cycle, including evaporation from the oceans, water vapor in the atmosphere, clouds, precipitation, soil moisture, sea ice, land ice, and snow cover on the land and ice. Aqua was launched on May 4, 2002, and carries six Earth-observing instruments in a near-polar low-Earth orbit. MODIS, which acquired the image above, is a 36-band spectroradiometer that measures physical properties of the atmosphere, oceans and land.
NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response Team at NASA GSFC. Graph by Jesse Allen based on modeled ice volume data from the Polar Science Center, University of Washington. Caption portions by Michon Scott with information from Ted Scambos, National Snow and Ice Data Center.
An “ice island” that calved from the Petermann Glacier in July is seen by NASA satellite (MODIS/Terra)
Remember that enormous slab of ice that broke off Greenland’s Petermann Glacier back in July? It’s now on its way out to sea, a little bit smaller than it was a couple of months ago — but not much. At around 10 miles long and 4.6 miles across (16.25 x 7.5 km) this ice island is actually a bit shorter than Manhattan, but is fully twice as wide.
The image above was acquired on September 14 by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite.
Although the calving of this particular ice island isn’t thought to be a direct result of increasing global temperatures, climate change is thought to be a major factor in this year’s drop in Arctic sea ice extent, which is now below 4.00 million square kilometers (1.54 million square miles). Compared to September conditions in the 1980s and 1990s, this represents a 45% reduction in the area of the Arctic covered by sea ice.
Arctic sea ice extent data for June-July 2012 (NSIDC)
This year sea ice in the Arctic Ocean dropped below the previous all-time record, set in 2007. 2012 also marks the first time that there has been less than 4 million square kilometers (1.54 million square miles) of sea ice since satellite observations began in 1979.
The animation below, released today by the NOAA, shows the 2012 time-series of ice extent using data from the DMSP SSMI/S satellite sensor:
Petermann glacier, a 70 km (43 mile) long tongue of ice that flows into the Arctic Ocean in northwest Greenland, recently calved an “ice island” approximately 130 square kilometers (50 sq. miles) — about twice the area of Manhattan. The image above, acquired by NASA’s Terra satellite, shows the ice island as it drifts toward the ocean five days after breaking off the main glacier.
Petermann glacier has been known for birthing massive ice islands; previously in August 2010 an even larger island broke away from the glacier, measuring 251 square kilometers (97 sq. miles). That slab of ice eventually drifted into the northern Atlantic and was even visible from the Space Station a year later!
Although some of Greenland’s glaciers have been observed to be quickening their seaward pace as a result of global warming, this particular calving event — which occurred along a crack that appeared in 2001 satellite imagery — isn’t thought to be a direct result of climate but rather of ocean currents and isn’t expected to have any significant effect on the rate of Greenland’s ice loss as a whole. Still, satellite observation of such events provides valuable data for researchers monitoring the processes that are involved with rapidly accelerating Arctic ice loss.
And if you want an idea of what a slab of ice this large looks like up close, here’s a video taken by researchers on approach to a smaller chunk of the 2011 island:
NASA Earth Observatory image by Jesse Allen, using data from NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. (NASA/Terra)
