Venus really sucks. It’s as hot as an oven with a dense, poisonous atmosphere. But how did it get that way?
Venus sucks. Seriously, it’s the worst. The global temperature is as hot as an oven, the atmospheric pressure is 90 times Earth, and it rains sulfuric acid. Every part of the surface of Venus would kill you dead in moments.
Let’s push Venus into the Sun and be done with that terrible place. Its proximity is lowering our real estate values and who knows what sort of interstellar monstrosities are going to set up shop there, and be constantly knocking on our door to borrow the mower, or a cup or sugar, or sneak into our yard at night and eat all our dolphins.
You might argue that Venus is worth saving because it’s located within the Solar System’s habitable zone, that special place where water could exist in a liquid state on the surface. But we’re pretty sure it doesn’t have any liquid water. Venus may have been better in the past, clearly it started hanging out with wrong crowd, taking a bad turn down a dark road leading it to its current state of disrepair.
Could Venus have been better in the past? And how did it go so wrong? In many ways, Venus is a twin of the Earth. It’s almost the same size and mass as the Earth, and it’s made up of roughly the same elements. And if you stood on the surface of Venus, in the brief moments before you evacuated your bowels and died horribly, you’d notice the gravity feels pretty similar.
In the ancient past, the Sun was dimmer and cooler than it is now. Cool enough that Venus was much more similar to Earth with rivers, lakes and oceans. NASA’s Pioneer spacecraft probed beneath the planet’s thick clouds and revealed that there was once liquid water on the surface of Venus. And with liquid water, there could have been life on the surface and in those oceans.
Here’s where Venus went wrong. It’s about a third closer to the Sun than Earth, and gets roughly double the solar radiation. The Sun has been slowly heating up over the millions and billions of years. At some point, the planet reached a tipping point, where the water on the surface of Venus completely evaporated into the atmosphere.
Water vapor is a powerful greenhouse gas, and this only increased the global temperature, creating a runaway greenhouse effect on Venus. The ultraviolet light from the Sun split apart the water vapor into oxygen and hydrogen. The hydrogen was light enough to escape the atmosphere of Venus into space, while the oxygen recombined with carbon to form the thick carbon dioxide atmosphere we see today. Without that hydrogen, Venus’ water is never coming back.
Are you worried about our changing climate doing that here? Don’t panic. The amount of carbon dioxide released into the atmosphere of Venus is incomprehensible. According to the IPCC, the folks studying global warming, human activities have no chance of unleashing runaway global warming. We’ll just have the regular old, really awful global warming. So, it’s okay to panic a bit, but do it in the productive way that results in your driving your car less.
The Sun is still slowly heating up. And in a billion years or so, temperatures here will get hot enough to boil the oceans away. And then, Earth and Venus will be twins again and then we can push them both into the Sun.
I know, I said the words “climate change”. Feel free to have an argument in the comments below, but play nice and bring science.
Predicting the weather here on Earth is never an easy thing, but predicting it on Mars may be ever trickier. Such is the argument presented by a recent study concerning “macroweather” patterns on the Red Planet, a new regime for understanding how planetary environments work.
When it comes to describing the climate of a planet, two important concepts come into play. First, there’s weather, which covers day-to-day changes due to fluctuations in the atmosphere. Second, there’s climate, which is more stable and subject to change over the course of decades. Macroweather, the latest addition to the game, describes the relatively stable periods that exist between short-term weather and long-term climate.
For those of us dwelling here on planet Earth, these are familiar concepts. But researchers say this same three-part pattern applies to atmospheric conditions on Mars. The results of a new paper, published today in Geophysical Research Letters also show that the Sun plays a major role in determining macroweather.
The scientists chose to study Mars because of the wealth of data it has provided in recent decades, which they then used to test their theory that a transitional “macroweather” regime exists on a planet other than Earth. They used information collected from the Viking Mars lander mission from the 1970s and 1980s, and more recent data from the Mars Global Surveyor.
By taking into account how the sun heats Mars, as well as the thickness of the planet’s atmosphere, the scientists predicted that temperatures and wind would fluctuate on Mars similar to how they fluctuate on Earth. However, this transition from weather to macroweather would take place over 1.8 Martian days (about two Earth days), compared with a week to 10 days here on Earth.
“Our analysis of the data from Mars confirmed this prediction quite accurately,” said Shaun Lovejoy, a physics professor at McGill University in Montreal, Canada, and lead author of the paper. “This adds to evidence, from studies of Earth’s atmosphere and oceans, that the sun plays a central role in shaping the transition from short-term weather fluctuations to macroweather.”
The findings also indicate that weather on Mars can be predicted with some skill only two days in advance, compared to 10 days on Earth.
“We’re going to have a very hard time predicting the weather on Mars beyond two days given what we have found in weather records there,” said co-author Jan-Peter Muller from the University College London Mullard Space Science Laboratory in the UK, “which could prove tricky for the European lander and rover.”
This research promises to advance scientists’ understanding of the dynamics of Earth’s own atmosphere, and could potentially provide insights into the weather of Venus, Saturn’s moon Titan, and possibly the gas giants Jupiter, Saturn, Uranus, and Neptune.
As always, in learning about other planets and their climates, scientists are finding that the planets of our Solar System may have more in common with Earth than previously thought. Because of this, studying these other worlds will inevitably help us to better understand our own.
Hurricane Gonzalo, the first major Atlantic Ocean basin hurricane in three years, has strengthened to a dangerous Category 4 storm, threatening Bermuda and forcing a postponement of the upcoming launch of the Orbital Sciences Antares rocket to the space station from the Virginia shore to no earlier than Oct. 27.
A hurricane warning is in effect for the entire island of Bermuda.
NASA and Orbital Sciences had no choice but to delay the Antares blastoff from Oct. 24 to no earlier than Oct. 27 because Bermuda is home to an “essential tracking site” that must be operational to ensure public safety in case of a launch emergency situation.
Antares had been slated for an early evening liftoff with the Cygnus cargo carrier on the Orb-3 mission to the International Space Station (ISS).
NASA and Orbital issued the following statement:
“Due to the impending arrival of Hurricane Gonzalo on the island of Bermuda, where an essential tracking site used to ensure public safety during Antares launches is located, the previously announced “no earlier than” (NET) launch date of October 24 for the Orb-3 CRS mission to the International Space Station for NASA is no longer feasible.”
The powerful Gonzalo is currently expected to make a direct hit on Bermuda on Friday afternoon, Oct. 17. It’s packing devastating maximum sustained winds exceeding 145 mph (225 kph).
NASA and NOAA satellites including the Terra, Aqua and GOES-East satellites are providing continuous coverage of Hurricane Gonzalo as it moves toward Bermuda, according to a NASA update today.
Tropical storm force winds and 20 to 30 foot wave heights are expected to impact Bermuda throughout Friday and continue through Saturday and into Sunday.
“The National Hurricane Center expects hurricane-force winds, and rainfall totals of 3 to 6 inches in Bermuda. A storm surge with coastal flooding can be expected in Bermuda, with large and destructive waves along the coast. In addition, life-threatening surf and riptide conditions are likely in the Virgin Islands, Puerto Rico, Dominican Republic, Bahamas. Those dangerous conditions are expected along the U.S. East Coast and Bermuda today, Oct. 16,” according to NASA.
After the hurricane passes, a team will be sent to assess the impact of the storm on Bermuda and the tracking station. Further delays are possible if Bermuda’s essential infrastructure systems are damaged, such as power, transportation and communications.
The Antares/Cygnus rocket and cargo ship launch from the Mid-Atlantic Regional Spaceport at NASA’s Wallops Flight Facility along the eastrn shore of Virginia.
Liftoff is currently target for October 27 at 6:44 p.m. (EDT). The rendezvous and berthing of Cygnus with the ISS remains on November 2, with grapple of the spacecraft by the station’s robotic arm at approximately 4:58 a.m. (EST), according to a NASA update.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
138 million miles and 10 months journey from planet Earth, MAVEN moved into its new home around the planet Mars this evening. Flight controllers at Lockheed Martin Space Systems in Littleton, Colorado anxiously monitored the spacecraft’s progress as onboard computers successfully eased the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft into Mars orbit at 10:24 p.m. Eastern Daylight Time.
Shortly before orbital insertion, six small thrusters were fired to steady the spacecraft so it would enter orbit in the correct orientation. This was followed by a 33-minute burn to slow it down enough for Mars’ gravity to capture the craft into an elliptical orbit with a period of 35 hours. Because it takes radio signals traveling at the speed of light 12 minutes to cross the gap between Mars and Earth, the entire orbital sequence was executed by onboard computers. There’s no chance to change course or make corrections, so the software has to work flawlessly. It did. The burn, as they said was “nominal”, science-speak for came off without a hitch.
“This was a very big day for MAVEN,” said David Mitchell, MAVEN project manager from NASA’s Goddard Space Flight Center, Greenbelt, Maryland. “We’re very excited to join the constellation of spacecraft in orbit at Mars and on the surface of the Red Planet. Congratulations to the team for a job well done today.”
Over the next six weeks, controllers will test MAVEN’s instruments and shape its orbit into a long ellipse with a period of 4.5 hours and a low point of just 93 miles (150 km), close enough to get a taste of the planet’s upper atmosphere. MAVEN’s one-Earth-year long primary mission will study the composition and structure of Mars’ atmosphere and how it’s affected by the sun and solar wind. At least 2,000 Astronomers want to determine how the planet evolved from a more temperate climate to the current dry, frigid desert.
Vast quantities of water once flowed over the dusty red rocks of Mars as evidenced by ancient riverbeds, outflow channels carved by powerful floods, and rocks rounded by the action of water. For liquid water to flow on its surface without vaporizing straight into space, the planet must have had a much denser atmosphere at one time.
Mars’ atmospheric pressure is now less than 1% that of Earth’s. As for the water, what’s left today appears locked up as ice in the polar caps and subsurface ice. So where did it go all the air go? Not into making rocks apparently. On Earth, much of the carbon dioxide from volcanic outgassing in the planet’s youth dissolved in water and combined with rocks to form carbon-bearing rocks called carbonates. So far, carbonates appear to be rare on Mars. Little has been seen from orbit and in situ with the rovers.
During the year-long mission, MAVEN will dip in and out of the atmosphere some 2,000 times or more to measure what and how much Mars is losing to space. Without the protection of a global magnetic field like the Earth’s, it’s thought that the solar wind eats away at the Martian atmosphere by ionizing (knocking off electrons) its atoms and molecules. Once ionized, the atoms swirl up the magnetic field embedded in the wind and are carried away from the planet.
Scientists will coordinate with the Curiosity rover, which can determine the atmospheric makeup at ground level. Although MAVEN won’t be taking pictures, its three packages of instruments will be working daily to fill gaps in the story of how Mars became the Red Planet and we the Blue.
For more on the ongoing progress of MAVEN later tonight and tomorrow, stop by NASA TV online. You can also stay in touch by following the hashtags #MAVEN and #JourneytoMars on social media channels including Twitter, Instagram and Facebook. Twitter updates will be posted throughout on the agency’s official accounts @NASA, @MAVEN2Mars and @NASASocial.
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.”
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.
“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.”
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.”
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.
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.
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.”
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.
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.”
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.
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.
“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.
“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.
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.
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.
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.