Tag Archives: climate

The New Climate Dice

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During the extreme heat waves and droughts of the early 1980s, climatologist James Hansen noticed coincident public discussions about the possible link of extreme events to climate change. He says discussion cooled, however, when natural variability turned up a season with average or cold temperatures. In 1988, another heat wave and drought wiped out crops in the U.S. Midwest, and resulted in more than 5,000 deaths, according to NOAA’s National Climatic Data Center. That same year, Hansen introduced the analogy of loaded dice to demonstrate variability and the growing frequency of extreme temperature events.

On one of the six-sided dice, Hansen painted two sides blue, two sides white, and two sides red to represent the chance of a cold, average, or warm summer season, respectively. That’s how the dice would have rolled from 1951 to 1980, when climate was relatively stable. On the other die – this one loaded – Hansen painted one side blue, one side white, and four sides red. That’s how climate models suggested the dice would roll by the first decade of the 21st century, should the increase of greenhouse gases in the atmosphere play out as it did.

“If you keep track for several seasons you notice the frequency of the anomalies has now changed, and you’re getting much more of those on the warm side than on the cool side,” Hansen says.

The changes that Hansen and colleagues calculated in 1988 turned out to be close to reality, as far as how many sides of the dice would now be red as opposed to blue to represent today’s climate. But a key difference between the 1988 dice and the new climate dice is the addition of an entirely new color. Almost one full side previously red is now brown, representing a new category of extreme hot events.

“I didn’t think about adding another color in 1988,” Hansen says. “Since then I have realized that the extreme cases are the most interesting and hold the most potential for impact, such as we’re seeing this summer in the case of the drought and devastated corn crop.”

The division between warm and cool will continue to change in the future, Hansen says. “But it’s still a crapshoot and you shouldn’t take one cool season as an indication that there’s something wrong with our understanding of global temperature and warming.”

Hansen and colleagues continue to use the dice for communication purposes, but they now employ a different statistical tool – the bell curve – that they say better demonstrates the change in temperature anomalies, particularly at the extremes.

Text by Kathryn Hansen. Top image: James Hansen of NASA’s Goddard Institute for Space Studies. Credit: NASA

NPP Launches: Put on Your Calibration and Validation Shoes

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The NPOESS Preparatory Project (NPP)
, NASA’s newest Earth-observing satellite, roared into space on October 28th on a mission to improve understanding of how Earth’s climate (and weather) works by extending a variety of environmental data records established by an earlier generation of satellites.

There’s been plenty of good coverage of the hubbub and the careful engineering that goes into every NASA launch but less that gets into the nitty-gritty of the new science data that the satellite will provide.

What exactly will the mission’s science team do once NPP starts to produce data? What sorts of science issues will NPP-funded researchers tackle?

The answers to such questions are tucked away in a hard-to-find document (pdf) in the science section of NPP’s website. Though technical and filled with acronyms and jargon, it’s well worth reading if you want to understand what the NPP science team will be focused on in the coming months.

My four sentence summary: Teams of researchers charged with using NPP to monitor a whole slew of environmental phenomena (think, for example, atmospheric ozone levels, sea surface temperatures, cloud properties, fire activity, vegetation cover, ocean color, land surface temperatures, aerosol particles, snow cover, the planet’s albedo, and air pollutants such as sulfur dioxide) will be doing everything they possibly can to make sure the data NPP’s instruments provide can be merged seamlessly with measurements taken by an earlier generation of satellites. Sounds easy enough, I know. It’s not. Lots and lots of careful calibration and validation work is required because four of NPP’s instruments are significantly different than the instruments that preceded them.

To the NPP scientists about to embark on the task: Bon Voyage!

Text by Adam Voiland.  Launch #1 video published originally on Geeked on Goddard. Launch imagery available in the NPP press kit. Launch video #2 published originally by NASA Television’s YouTube Channel

Black Carbon's Day on the Hill

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Drew Shindell (left), Veerabhadran Ramanathan, and Tami Bond speak with Representative Edward Markey after the three scientists testified. Credit: NASA/Voiland

Leading aerosol scientists, including NASA’s Drew Shindell, explained the intricacies of a sooty component of smoke called black carbon to members of the Select Committee on Energy Independence and Global Warming during a hearing on Capitol Hill last month.

Their message: controlling black carbon emissions could be a win-win for both human health and the environment.

Not only can partially combusted particles of carbon lodge in the human respiratory system and cause disease, the panelists explained, they also contribute to climate change by warming the atmosphere and changing the way Earth reflects sunlight back into space.

Three lawmakers—Representative Edward Markey (D-Mass.), Representative Jay Inslee (D-Wash.), and Representative Emanuel Cleaver (D-Mo.)—questioned the scientists.

Tami Bond, a black carbon specialist from the University of Illinois, began the hearing by offering a summary of black carbon’s potent short-term climate impacts. She noted, for example, that:

•     One ounce of black carbon absorbs as much sunlight as would fall on an entire tennis court.

•     A pound of black carbon absorbs 650 times as much energy during its one-to-two week lifetime as one pound of carbon dioxide gas would absorb during 100 years.

•     An old diesel truck driving 20 miles would emit about one-third of an ounce of black carbon and 70 pounds of carbon dioxide. The carbon dioxide from that truck would have five times the warming power of the black carbon, but it would spread out over 100 years. The truck’s more potent black carbon impact would have an effect in the span of a few weeks.

Drew Shindell, a climate modeler from NASA’s Goddard Institute for Space Studies (GISS) in New York City, provided more details about where black carbon comes from and how much impact it has on Earth’s climate.

As seen in this scanning electron microscope still image, small chain-like aggregates of soot cling to larger sulfate aerosol particles.  Credit: Arizona State University/Peter Buseck

Diesel vehicles, agricultural burning and wildfires, and residential cooking stoves are key sources of black carbon. However, combustion that occurs at higher temperatures — such as the type that takes place in power plants — does not produce much of the substance.

Shindell said climate models from NASA GISS and elsewhere show that 15 to 55 percent of global warming is due to black carbon. The wide range is primarily because of incomplete knowledge about how black carbon and clouds interact.

One of the more interesting questions came from Rep. Inslee, who asked the scientists whether black carbon’s impact is due to the fact that it absorbs sunlight and warms the atmosphere, or because it covers snow and ice with dark soot, which reduces Earth’s albedo and makes the planet less reflective.

Veerabhadran Ramanathan , a professor at the Scripps Institution of Oceanography, responded: “The albedo effect contributes about 10 percent of the total black carbon effect. But if you look in the Arctic or in the alpine glaciers, then the darkening effect may be the dominant effect.”

Shindell added that the scientific understanding of black carbon’s impact varies by region. “In places like the Himalayas, the results are somewhat ambiguous,” said Shindell. Over Himalayan glaciers, large amounts of dust — which also absorb radiation — and other pollutants in the air may dampen the effect. “In the Arctic, which tends to be very far from dust sources, the snow is very clean, so the effect is extremely large.” Increasing levels of black carbon combined with decreasing levels of sulfates may account for more than half of the accelerated warming in the last few decades, Shindell’s research suggests. 

Inslee also expressed frustration about the lack of understanding of science and climate change among his fellow lawmakers.”If I was scientist and I knew what was going on out there, I’d be in somebody’s grill, telling them we need action,” he said. “And yet you just don’t see that from the scientific community….Why doesn’t that happen? Should it happen?”

 Drew Shindell testifies as Veerabhadran Ramanathan looks on.
Credit: Committee on Energy Independence and Global Warming

The scientific method and the culture of scientists, Bond replied, makes it very difficult for scientists to lobby lawmakers or advocate a policy position and remain credible. “This is a difficult question and has to do with the nature of scientists and how they approach science,” she said. “If you have an action outcome, one is almost afraid that you’ll affect the science because you’re supposed to look at it dispassionately. How we conduct our business, 99.9 percent of the time, we must step back from what we want the outcome to be. We’re not allowed to want an outcome.”

Adam Voiland, NASA’s Earth Science News Team

Has Sulfate Pollution from Asia Masked a Decade of Warming?

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Warming overwhelms the cooling effect of sulfates by about 2045 even if China and India continue to grow rapidly and delay pollution controls. Radiative forcing is a measure of influence that a climate factor has in altering the balance of Earth’s incoming and outgoing energy. Positive forcing tends to warm the surface, whereas negative forcing tends to cool it. A more detailed definition of radiative forcing is available here.

Science News
, the Washington Post, and Climate Central have all written about a new study, published this week by the Proceedings of the National Academy of Sciences, that suggests a decade-long lull in global warming, which has caused some commentators to question the scientific underpinnings of climate change, stems from large increases in sulfur dioxide emissions in Asia.
Between 2003 and 2007, global sulfur emissions have gone up by 26 percent. In the same period, Chinese sulfur dioxide emissions have doubled.

While burning coal is best known for emitting carbondioxide, a greenhouse gas, the sulfur dioxide the same process generates leads to the formation ofreflective sulfate particles that have the opposite effect on the climate. Releasing sulfates might seem, then, like a reasonable way to counteract global warming, but there’s a catch. Sulfates also cause acid rain and health problems. The World Health Organization estimates that air pollution, including sulfates, causes as many as 2 million premature deaths each year.

The combination of the contradictory coal burning impacts leaves policy makers in a bind: clean up the sulfates and accelerate the pace of global warming or allow sulfates to build up and people will die directly of air pollution. Reducing sulfate is relatively cheap and the health benefits don’t take long to realize, so most industrialized countries end up adopting pollution controls that reduce sulfate emissions. The United States, as well as industrialized European countries and Japan, cut sulfate emissions significantly in the 1970s and 1980s, and there’s little reason to believe that China will follow a different path.

In fact, the Chinese government is already in the midst of an effort to reduce sulfate pollution. A team of researchers, including NASA Goddard’s Mian Chin, used satellite imagery and other data about emissions to estimate sulfate emission trends in China in a 2010 paper published in Atmospheric Chemistry and Physics They found that sulfur dioxide emissions increased dramatically between 2000 and 2005, particularly in Northern China. But they also found that sulfur dioxide emissions in China, which I wrote about in an earlier post, began to decline in 2006 after the government began installing large numbers of flue-gas desulfurization (FGD) devices in coal power plants.

Since 2006, flue-gas desulfurization (FGD) devices in coal power plants have caused sulfur dioxide emissions from power plants in China to begin declining.

What does it all mean for the climate? In 2010, Drew Shindell and Greg Faluvegi of NASA’s Goddard Institute for Space Studies simulated a number of emission scenarios for China and India to find out. They looked, for example, at how the climate would respond if the Chinese and Indian economies continue to expand rapidly or only grow at a moderate pace. Likewise, they modeled what would happen if China and India instituted sulfate pollution controls immediately or waited a number of decades before doing so.

In their paper, Shindell and Faluvegi present their results, shown in the line graph at the beginning of this post, as a suite of projections. The strength of warming predicted depends on whether the economies continue to grow quickly and whether sulfate pollution slows, but there is one common – and concerning – similarity between all of the projections: regardless of how fast China or India grow or put off sulfate pollution controls, it’s not enough to mask warming from carbon dioxide in the long term, particularly in the mid-latitudes of the Northern Hemisphere where the climate impacts of sulfates from Asia are the most noticeable.

Here’s how the GISS authors explained the situation:

We find that while the near-term effect of air quality pollutants is to mask warming by CO2, leading to a net overall near-term cooling effect, this does not imply that warming will not eventually take place. Worldwide application of pollution control technology in use in Western developed countries and Japan along with continued CO2 emissions would lead to strong positive forcing in the long term irrespective of whether the pollution controls are applied immediately or several decades from now. Continued emissions at current (year 2000) pollutant and CO2 levels may have little near-term effect on climate, but the climate ‘debt’ from CO2 forcing will continue to mount. Once pollution controls are put into place as society demands cleaner air it will rapidly come due, leading to a “double warming” effect as simultaneous reductions in sulfate and increases in CO2 combine to accelerate global warming. The only way to avoid this would be not to impose pollution controls and to perpetually increase sulfur-dioxide emissions, which would lead to a staggering cost in human health and is clearly unsustainable.

Text by Adam Voiland. Imagery first published in Atmospheric Chemistry and Physics.  

Aquarius Launches to Survey Earth's Salty Sea

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Joe Witte
filed this report from the media viewing site at Vandenberg Air Force Base shortly before the Aquarius satellite blasted successfully into space

More than a dozen reporters from Argentina are either standing or slowly moving about trying to stay warm while waiting for the launch of the Aquarius satellite. The low cloud deck over Vandenberg Air Force Base in California puts a damper on their spirits after traveling all the way from South America to see a Delta II rocket quickly disappear on it’s way to an orbit 400 miles above the earth.

Scientists from Argentina collaborated with NASA researchers to develop a highly specialized instrument to measure the amount of salt in the world’s oceans. It has taken nearly three decades of research and technical development to get to this point. Thirty years of work will disappear into the fog in a couple of seconds.

If all goes well after about 30 days of testing and calibrating, the satellite will be sending down valuable data on the salinity of the oceans.

The amount of salt in a parcel of water, along with the water’s temperature, determines the buoyancy of a parcel or body of water. For instance, along the southern east coast of the US the Gulf Stream becomes very salty because the tropical sun warms the ocean surface and produces evaporation from the ocean.Evaporation leaves salt behind in the ocean water at the surface leaving the Gulf Steam especially salty.

The salty water cools as the Gulf Stream flows into the northern areas off Canada with colder air temperatures. Cold temperatures and high salinity result in dense water, which slowly sinks into the depths of the northern Atlantic. This process is what drives the deep ocean circulation around the whole Earth. Since 70 percent of the planet is ocean the effects on climate are very significant. 

Over the coming years, climate scientists and oceanographers expect to make many new discoveries with Aquarius data.

Top image credit: NASA/Bill Ingalls. Lower image credit: NASA/Joe Witte. Text by Joe Witte.

A Moment for Glory

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NASA held a press conference about its soon-to-launch Glory satellite on January 20 in Washington, DC. The  mission will advance understanding of the energy budget and climate change by taking critical measurements of aerosols and total solar irradiance.

Want to learn more about Glory? Read an overview of the mission, view one of these two image galleries, brush up on aerosol science, take a look at this Q & A (pdf), follow along on Twitter, or browse the mission websites. Also, see what Nature, Discovery, and SpaceFlight Now have to say about Glory.

–Adam Voiland, NASA’s Earth Science News Team

Is Coagulation Geoengineering's Achilles' Heel?

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Jason English, a graduate student at the University of Colorado at Boulder and a participant in NASA’s Graduate School Researchers Program, chats with us about some of his recent research into geoengineering.

WoE: Do you find there is a taboo of sorts against studying geoengineering among Earth scientists? It’s fairly unusual to see the topic come up at conferences, so your poster caught our eye.

English: There is more acceptance of studying it in just the last couple of years. I think scientists are facing the reality that countries aren’t doing much to slow the emissions of greenhouse gases. Eventually, we may have to choose between the risks and consequences of climate change and the risks and consequences of climate engineering. The only way to make an educated decision about that is to study it.

WoE: What type of geoengineering are you focusing on?

English: For my PhD, I have been looking at stratospheric aerosols.

WoE: Hold up. What are stratospheric aerosols?

English: They’re the tiny particles that are aloft in the atmosphere about 20 kilometers above the surface of the Earth. One of the leading geoengineering ideas is to inject aerosols into the stratosphere. I decided, after getting help and input from colleagues such as Michael Mills and Brian Toon, to set up a computer model that would analyze exactly how something like that would work.

WoE: And what do stratospheric aerosols have to do with climate?

English: People have suggested we could use a type of a particle for geoengineering that is actually composed of tiny droplets of sulfuric acid. Those are called sulfates. Sulfates reflect sunlight. If you have a layer of these particles up in the stratosphere they reflect part of the incoming solar radiation from the sun back to space. Overall, they have a cooling effect.

WoE: And sulfates can make it all the way up to the stratosphere?

English: Yes, some of the stronger volcanic eruptions can send particles into the stratosphere. They take a couple of years to settle back down to the surface. Very tiny amounts from power plants and other sources can also make it up that far.

WoE: I get that you modeled what might happen if humans decided to inject sulfates into the stratosphere, but what was the precise question you set out to answer?

English: There have been a few other scientists who have looked at geoengineering using stratospheric aerosols, but they didn’t simulate all the processes that can affect the particles. Recently, a team led by Patricia Heckendorn, a researcher based in Zurich, simulated all of these processes in a 2D model and found that the effectiveness of sulfate geoengineering diminished as more sulfate was added. I wanted to use a 3D model that looked at all of the processes, and I wanted to compare our results to Heckendorn’s.

WoE: What processes did you include that others didn’t?

English: For example, our model simulates coagulation, the process by which multiple particles can combine to become one. We also included nucleation – that’s when tiny gas molecules condense on each other to form liquid droplets. Also condensational growth. If you watch, say, water drops grow bigger and bigger on a piece of grass on a foggy morning you’re looking at condensational growth.

WoE: What did you find when you included all of that in your model?

English: What we found was that effective geoengineering required injecting larger masses of sulfuric acid than some have hoped because the particles coagulate and get much bigger than thought. Larger particles fall out of the stratosphere faster to the surface, so they’re not as effective at reflecting light. This matched Heckendorn’s results.

WoE: How much less effective?

English: It depends on how much sulfate we add. The more we add the less effective they become.

WoE: That’s the opposite of what people probably think…

English: It still gets more effective as you add more, but it has a diminishing return. We haven’t done a detailed assessment yet, but the group led by Heckendorn did, and they had a similar result. They found that you would need to inject more than 10 million metric tons of sulfur into the stratosphere per year if you wanted to offset the current forcing from greenhouse gases. People used to think it could be done with about 3 million metric tons.

WoE: Ten million metric tons sure sounds like a lot.

English: It is. Mount Pinatubo released about 10 million metric tons, but that was a one-time shot. Basically, we would need one or two Mount Pinatubo’s every single year.

WoE: Where do we go from here?

English: These results were surprising. If geoengineering is going to work, I think we’re realizing that scientists will need to look at new and creative ways to add particles to the stratosphere in such a way that they don’t grow too big and fall out too quickly.

Image Information: Astronauts took this image of Mount Etna erupting in 2002. Credit: NASA/JSC/Gateway to Astronaut Photography. The lower image is courtesy of Jason English.

–Adam Voiland, NASA’s Earth Science News Team

Searching for Rainbows

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Image courtesy of Earth Science Picture of the Day. Credit: David Lien, Planetary Science Institute

Ubiquitous airborne particles called aerosols, which can have a big impact on the energy budget, are one the most poorly understood factors that influence our climate. Could searching for rainbows help scientists pinpoint the impact of the perplexing particles? Brain Cairns, the instrument scientist for the Aerosol Polarimetery Sensor (APS) on NASA’s Glory Mission, explains:

“The way that we diagnose whether we have small aerosol particles, big aerosols particles, non-spherical particles, ice particles, cloud droplets is primarily using polarization.

This is the most obvious and visually enticing example of polarization. On the left, is a picture that shows a rainbow. A polarizer was used, so you can actually see that rainbow. On the right, there’s no rainbow because there was no polarizer. The reflected light is so bright you simply can’t see the rainbow without a polarizer.

Why do we want to measure things like rainbows? It’s because the angular distribution and color of that light tells you exactly how big those close droplets are, and it tells you what the width of the size distribution is. This kind of information is what we use when we’re trying to diagnose how clouds form.”

–Adam Voiland, NASA’s Earth Science News Team

Speaking of Contrails…

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The prospect of a renegade missile transfixed newscasters last week after a videographer captured imagery of an unusual contrail near the coast of California. The now notorious plume initially baffled commentators as it seemed to point vertically into space and appeared larger than a standard airplane contrail.

The reality, which trickled out in the days following the uproar, turned out to be far less dramatic than some of the more inventive theories circulating. Most experts now say the mysterious plume was the product of a jet. The time of day and the particular trajectory of the jet conspired to create the illusion.

Sure, it might seem like a letdown, but here at What on Earth we would argue that jet contrails are perfectly fascinating in their own right. Where on Earth do they come from? The cirrus-cloud like condensation trails form when water vapor condenses and freezes around tiny airborne particles called aerosols that spill from jet engines. 

NASA Langley Research Center, in Hampton, Va., hosts a thorough website that’s well-worth a look for those who happen to be contrail-curious. Langley points out, for example, that contrails are hardly monolithic, noting that there are actually three major varieties of contrails: short-lived, persistent, and persistent spreading.  Here’s how Langley describes the three types: 

Short-lived contrails look like short white lines following along behind the plane, disappearing almost as fast as the airplane goes across the sky, perhaps lasting only a few minutes or less. The air that the airplane is passing through is somewhat moist, and there is only a small amount of water vapor available to form a contrail. The ice particles that do form quickly return again to a vapor state.

Persistent (non-spreading) contrails look like long white lines that remain visible after the airplane has disappeared. This shows that the air where the airplane is flying is quite humid, and there is a large amount of water vapor available to form a contrail. Persistent contrails can be further divided into two classes: those that spread and those that don’t. Persistent contrails look like long, narrow white pencil-lines across the sky.

Persistent spreading contrails look like long, broad, fuzzy white lines. This is the type most likely to affect climate because they cover a larger area and last longer than short-lived or persistent contrails.

Meanwhile, Our Changing Planet, a book co-edited by a number of NASA scientists that offers a good overview of remote sensing, devotes a chapter to climate impacts of the ubiquitous artificial clouds. Via Our Changing Planet:

Persistent contrails also play a role in climate because they reflect sunlight and trap infrared radiation just like their naturally formed cousins.  Thus, the presence of a contrail cluster in an otherwise clear sky can diminish the amount of solar energy reaching the surface during the daytime and increase the amount of infrared radiation absorbed in the atmosphere at all times of day. Currently, the overall impact appears to be a warming effect, but research is continuing to unravel the role of this phenomenon in climate change.    

Another interesting tidbit from Our Changing Planet:

Persistent contrails can often grow into natural-looking cirrus clouds within a few hours, a phenomenon that is best observed from space.  Although they typically last for only 4-6 hours, some clusters have been observed to last more than 14 hours and travel thousands of kilometers before dissipating. These persistent contrails are estimated to have caused cirrus cloud cover to rise by three percent between 1971 and 1996 over the United States and are well-correlated with rising temperatures, though not the only cause of them. Increasing traffic in nearly every country of the world will cause a rise in global cirrus coverage unless the upper troposphere dries out or advances in air traffic management and weather forecasting or in aircraft propulsion systems can be used to minimized contrail formation.   

Indeed. Take a look at this mesmerizing data visualization of just a mere day of air traffic…

–Adam Voiland, NASA’s Earth Science News Team

Photo above of contrails in a star pattern by John Pertig, courtesy of NASA Langley Research Center.

Q & A: Michael Lefksy on Measuring Trees From Space

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Colorado State University researcher Michael Lefsky recently published the first global map of forest heights using data from an radar-like laser instrument — the Geoscience Laser Altimeter System (GLAS) — aboard NASA’s IceSat satellite. The work should help scientists build an inventory of how muchcarbon the world’s forests store and how fast that carbon cycles throughecosystems and back into the atmosphere. We spoke with Michael to learn more about the work behind his work…

What on Earth: How did you get into this line of work?

Lefsky: I went to the University of Virginia to study the modeling of forest structure. My graduate advisor was working with NASA, and one day he came back with a single waveform lidar graph, one of the first ever produced. That was it: I knew this was what I wanted to work on.

What on Earth: What do you mean by forest structure and why go to the trouble of studying it?

Lefsky: We were looking at things like the size and number of stems in forests. We were also looking at how forests change over time and across landscapes. It’s critical to understand forest structure if you want to understand how much carbon forests are storing. You need to know whether a forest is growing, in stasis, or has been disturbed. We used to study this kind of thing by basically counting stems. But when I looked at that waveform lidar data, I could see it was a record of exactly the same thing, but from a completely different perspective.

What on Earth: I’m guessing you could collect in seconds the same amount of data it takes weeks to get in the field?

Lefsky: Actually, less than a second.

What on Earth: But are there insights that you can get from the ground that you can’t get from space?

Lefsky: Sure, but you have to keep the scale in mind. In the field, we basically estimate forest height by measuring diameter of trunks at breast height. That’s sort of like trying to study a person’s size and metabolism by measuring the diameter of their ankles. Lidar gives you a whole bunch of new information about the vertical structure of forest canopy. This is something that’s hardly ever investigated from the ground, or could only be investigated with great difficulty.

What on Earth: What are the most satisfying and frustrating aspects of working with remote sensing data?

Lefsky: I love what I do. I am incredibly lucky. I don’t really see frustrations, just challenges. In this case, there are enormous challenges involved with working on a completely new kind of data and figuring out how to process such large amounts of information. The flip side is that coming to new levels of understanding about what’s going on in the world is incredibly satisfying.

What on Earth: If there was one thing you wish people knew about your science, what would it be?

Lefsky: I wish people knew what tremendous things NASA’s Earth Science Division does for our understanding and ability to plan for the future of the global environment. People think space shuttle. People think the Moon. I think that the Earth science part of NASA is woefully under-appreciated.

— Adam Voiland, NASA’sEarth Science News Team

The map (left) was created by NASA’s Earth Observatory, using data provided by Michael Lefsky (above).   

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