The Earth is a bit like the human body; its temperature is very finely balanced, and when it gets slightly out of whack big things can happen. In the case of our home planet, gases in the atmosphere play a vital role in maintaining this delicate equilibrium, by balancing the absorption and emission of all the electromagnetic radiation (microwaves, infrared waves, ultraviolet light and visible light, for example) reaching the surface of the Earth.

As we reported recently, the Earth is getting warmer. Scientists believe the main driver behind this warming trend is rising levels of man-made greenhouse gases; these gases, which we pump out into the air, act to trap heat radiation near the surface of the Earth that would otherwise be sent back out into space. Carbon dioxide (CO2) is the Paris Hilton of greenhouse gases, and gets a lot of face time because its concentration in the atmosphere has increased relatively rapidly since the Industrial Revolution. But methane, nitrous oxide, hydrofluorocarbons (HFCs), chlorofluorocarbons (CFCs) and perfluorocarbons (PFCs) are also important agents of global warming — some of them are actually much more potent than CO2 and they stick around for hundreds to thousands of years longer. This has some scientists concerned that these B-listers could actually impact global temperatures significantly more than CO2.

In a new paper, Partha Bera and colleagues at NASA Ames Research Center and Purdue University put these gases under the microscope to find out exactly why they are such powerful heat trappers. They focus on CFCs, HFCs and PFCs — all chemicals containing the atoms fluorine or chlorine — that are used in medicine, fridges and as solvents, among other things. By probing the molecular structure of these compounds, they have found that molecules containing several fluorine atoms are especially strong greenhouse gases, for two reasons. First, unlike many other atmospheric molecules, they can absorb radiation that makes it through our atmosphere from space. Second, they absorb the radiation (trap the heat) very efficiently, because of the nature of the fluorine bonds inside them. (In technical terms, fluorine atoms create a larger separation of electric charge within the molecule, and this helps the molecular bonds absorb electromagnetic radiation more effectively.) HFCs and other fluorine-based gases have been called “the worst greenhouse gases you’ve never heard of.” Now we know why.

Until now, scientists had not looked in detail at the underlying physical or chemical causes that make some molecules better global warmers than others. Bera and colleagues say that their work should help improve our “understanding [of] the physical characteristics of greenhouse gases, and specifically what makes an efficient greenhouse gas on a molecular level.” They hope their findings will be used by industry to develop more environmentally-friendly materials.

Coral reefs are incredibly fragile. Not only are most corals brittle, but they usually need pristine, clear, warm, relatively nutrient-free waters to survive. Over the past few decades, humans have put an enormous amount of pressure on coral reef environments by altering their waters and tearing up their foundations. Through water pollution, over fishing, direct physical damage, warmer ocean waters and increased acidity of the oceans, we are in danger of rapidly sending the world’s reefs into oblivion. NASA's recent Millennium Coral Reef Mapping Project found that less than two percent of coral reefs are within areas designated to limit human activities that can harm the reefs and the sea life living in and around them.

This image, taken by the NASA/USGS Landsat-7 satellite, shows Hawaii's Pearl and Hermes Atoll, which consists of a few small, sandy islands that are contained within a lagoon and surrounded by a coral reef. The island of coral is part of the recently designated Northwestern Hawaiian Islands Marine National Monument, the largest protected marine area in the world.

Climate change can be a daunting topic for most adults to grasp, let alone kids. That’s why we’ve just launched the kids’ version of our website, called “Climate Kids”, to help.

The site, which is geared towards students in grades 4 through 6, is, like our parent Global Climate Change website, rich in visuals and multimedia that help convey the science behind climate change. Ever wondered what a water balloon can teach us about climate change? Maybe not, but the kids’ site will tell you more. There’s also a “Climate Time Machine” that travels back and forth in time, illustrating the different climate change that has gone on in years gone by, and games such as “Go Green” and “Wild Weather Adventure”. The website endeavors to answer some of the big questions related to climate change, in a kid-friendly way.

Kids are the future. The planet is theirs. Hopefully our website can shine a little light on how our planet is changing and what their future might hold. You can find the kids' site linked from our home page.

Courtesy of NASA/USGS Landsat mission.

The Aland Islands are located in the Baltic Sea between eastern Sweden and southwestern Finland. They consist of the main island, Fasta Aland, which contains 90 percent of the population, and an archipelago to the east that is made up of over 6,500 islands. Approximately 25,000 inhabitants live on only 65 of the islands. This image was taken by the Landsat 7 satellite on April 19, 2003.

From Patrick Lynch,
NASA's Earth Science News Team

The S'COOL program has been encouraging students to help verify NASA satellite measurements and learn about clouds and climate for 13 years now. Credit: Science Directorate, NASA Langley Research Center.

That is the premise of NASA’s S’COOL (Students’ Cloud Observations On-Line) project. While a satellite passes overhead observing the radiation given off by Earth, S’COOL participants look upwards and take careful notes on the type and multitude of clouds in the sky.

This is not just for fun, and it's not just to get children and teens interested in the basics of atmospheric science. These observations are put to use by NASA scientists to verify that a satellite instrument overhead — the Clouds and the Earth’s Radiant Energy System (CERES) sensor — is accurately observing clouds from above. In some cases, CERES’ radiometers (energy-measuring devices) may interpret a glare or a land feature as a cloud. Student observations act as what’s known as a “ground truth” method to make sure the satellite is accurate.

The more observations, the better. In this regard, the gold star goes to the students at Chartiers-Houston Jr./Sr. High School in Houston, Pa. These students have made more than 5,000 observations for the S’COOL folks at NASA’s Langley Research Center. (5,276 observations as of 10 January, to be exact.) The number is a record and nearly the doubles the total reported by any other school.

The S’COOL program is beginning its 14th year and has inspired school children in more than 75 countries to take their cloud charts outside. Chartiers-Houston has long been among the most active in the program. Students can make observations anytime, but ideally they walk outside at the precise time that the satellite is passing over their town. They must know the types of clouds and know the recording methods to make useful observations. This requires, in other words, dedication.

Science teacher Gary Popiolkowski, who’s been leading students outside to look skyward since 2000, said he likes S’COOL because it allows students to get “involved doing real science, acting like real scientists.” He said his students even make observations after school and on weekends, on their own time.

“My students have developed a sense of pride in continuing our observations over the years,” he said. “Besides recording the scheduled observations, we also identify the clouds each period throughout the day as a daily class starter. S’COOL is integrated into our weather unit and fits into my philosophy of “no child left inside” as we constantly 'look up' anytime we are outside.”

Cross posted and adapted from NASA’s What on Earth blog. Patrick is based at NASA’s Langley Research Center in Virginia.

From Dr. Matt Rogers,
Research scientist, Colorado State University

Matt Rogers works on the CloudSat project, an international mission run by NASA’s Jet Propulsion Laboratory, Colorado State University and others. Matt has just returned a student climate change conference in Thailand.

Stepping off the plane in Phuket, Thailand after leaving some thirty hours before from Colorado was quite a temperature shock. Having just crunched through the snow on my front porch, I was now in the tropics, attending the Climate Change Education and Earth System Science workshop representing the CloudSat Education Network. CloudSat, NASA’s cloud-watching satellite mission, has several schools in Thailand engaged in cloud observations, which we use to calibrate CloudSat data products. I had planned to hold a two-day, pre-conference workshop where I would work with students and teachers on understanding the basics of clouds and climate change. Little did I know, standing there in the hot Phuket sun, exactly how much science I would be looking at in the days to come.

The workshop went great. Nearly fifty students aged 12-18 from all over Thailand attended, and with the help of graduate students and faculty from nearby Walailak University, who were hosting the conference in conjunction with the Thai Institute for the Promotion of Teaching of Science and Technology (IPST), we spent the two days going through a whirlwind of science topics. We answered questions about climate change and developed new strategies for students to do science research, both in Thailand and in partnership with our CloudSat-affiliated schools in the U.S.

Then, the conference started — nearly 200 students and teachers, presenting research from the last year. The spectrum of topics was incredible. They ranged from investigating the effect of clouds on radio transmission to developing techniques to estimate the amount of rainfall using CloudSat data (and validating their results using rain measurement gauges!). Students had tracked the effect of ground cover on rubber tree cultivation and had studied the increasingly earlier budburst of local flowering trees, which they linked to local climate change in their province. They are engaged in relevant and cutting-edge climate research, and the results they are obtaining are astonishing.

I've made many new friends in the last couple of days, renewed old friendships and watched in wonder as student scientists take the lead in important climate research. I know that these kids are walking away from this conference with a greater understanding of how we observe the Earth and its climate from space, but I also know that I leave this place with a wealth of knowledge gained by listening to the next generation of scientists presenting their research. And based on what I've seen in here in Thailand, the future is a bright one indeed.

--Matt Rogers

This image of Bombetoka Bay in northwestern Madagascar was taken in August 2000 by NASA’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument. Bombetoka Bay is an inlet of the Mozambique Channel, which separates Madagascar from Africa to the west. In the picture, water is sapphire and tinged with pink where sediment is particularly thick. Dense vegetation can be seen in deep green.

Just downstream is the second largest port of Madagascar — the town of Mahajanga — a road terminus and trade center that exports among other things sugar, coffee, spices, timber and vanilla. The surrounding area contains extensive coffee plantations.

From Dr. Josh Willis,
NASA/Jet Propulsion Laboratory oceanographer

This famous climate scientist I know used to always begin his talks on sea level rise by showing a cartoon of a bathtub. A faucet would fill up the bathtub, representing water coming from melting glaciers and ice sheets, and then a small campfire would add heat, causing the water to expand. It was a nice way of getting people to think about the causes of sea level rise. But you might guess that the real ocean is a bit more complicated than the cartoon lets on. And you’d be right. Even though it’s sometimes convenient to think of the ocean as a great big bathtub, where turning on the tap at one end raises the water level in the whole tub, real sea level rise doesn’t quite happen that way. To understand why, you first have to realize that ‘sea level’ isn’t really level at all.

There are lots of reasons why the oceans are not level. For example, vast ocean currents like the Gulf Stream in the Atlantic Ocean and the Kuroshio in the Pacific actually reshape the ocean surface, causing it to tilt. As the planet heats up, changes in the prevailing winds (which drive most of these ocean currents) cause changes in the currents, reshaping our ocean and changing local sea level as a result.

Just as global warming does not raise land temperatures evenly, global ocean warming is not the same everywhere around the globe. Some regions of the oceans are heating up faster than others, and because warm water takes up more space than cold water, those regions experience faster sea level rise.

Finally, the water locked away in the great ice sheets of Greenland and Antarctica also shapes the ocean surface. As the ice sheets melt and lose water to the oceans, our entire planet feels the effects. The movement of mass from the ice sheets to the oceans very slightly shifts the direction of Earth’s rotation. This, along with changes in the gravitational pull of the ice sheets on the oceans, will reshape sea levels further still.

So sea level rise is complicated, and the bathtub analogy just doesn’t cut it. Given all that, the image below is not that surprising. It shows how sea levels changed between 1993 and 2008 (yellow and red show rising sea levels, blue and green show falling). Since the early 1990s, space satellites have given us a bird’s-eye view of sea level change. They tell us that that sea level, averaged over the whole planet, has gone up by about 4.5 cm (1.8 inches) since 1993 — clear evidence of global warming. (To recap: global warming causes a) ocean water to warm up, expand, and take up more space; and b) glaciers to melt which add more water to the oceans.) But the patterns of sea level change tell a much more complicated story.

Most of the regional variations seen over this 16-year trend are related to changes in the ocean currents rather than the movement or melting of ice. Australia for example, where 80% of the population lives near the coast, has seen sea levels rise much more quickly than the rest of the planet. Meanwhile, along the California coast, sea level has stayed steady or even fallen a bit.

The question is whether these regional differences are part of natural climate cycles, or an effect of global warming? The answer is probably both, and scientists around the world are working hard to tell the difference.

So where does all this leave my friend’s bathtub analogy? High and dry, of course.

The change in the world’s sea level between 1993 and 2008. Black areas are land; colored are the oceans. Yellow and red regions show rising sea level, while green and blue regions show falling sea level. White regions are missing data during parts of the year. Nearly everywhere, sea level is rising, and the global average is clearly rising fast. But the patterns of sea level change (the regional variations) are complicated.

Credit: Altimeter data products include data from TOPEX/Poseidon, Jason-1 and Jason-2 and other satellites. Data products come from Ssalto/Duacs, distributed by Aviso, with support from CNES.

Editor's note: If you're interested in how sea level is changing around the globe check out our Climate Time Machine and Sea Level Viewer.

From Adam Voiland,
NASA Earth Science News Team

One of the posters — called Communicating with Congress (and Everybody Else) — brainstorms some of the pitfalls that make communicating climate science such a challenge. High on the list: jargon. Scientists use such a specialized language that it can be difficult for non-scientists to distill the meaning from certain scientific presentations or articles. Complicating matters more, there are some words that have distinctly different meanings to scientists and to the public. The poster highlighted a handful of them. I've taken the liberty of elaborating upon and defining a few of them below.

Did you know the difference? Have any good examples to add to the list?

Aerosols

• The Public: Spray cans that dispense a liquid mist, many of which damage Earth's ozone layer.
• Scientists: A suspension of any solid or liquid droplet in the atmosphere. Includes dust, soot, pollen, sea salt, sulfates and more.

Radiation

• The Public: Harmful material that leaks from nuclear material and is used to battle cancer.
• Scientists: Energy that comes from a source and travels through some material or space. Includes electromagnetic radiation such as radio waves, infrared light, visible light, ultraviolet light and X-rays.

Ozone

• The Public: Something in our atmosphere that protects against cancer-causing light waves.
• Scientists: A molecule containing three oxygen atoms that, in different parts of the atmosphere, acts as a harmful air pollutant, a heat-trapping greenhouse gas, and a buffer against ultraviolet radiation.

Error

• The Public: A mistake, an accidental wrong action or a false statement not made deliberately.
• Scientists: Not a mistake; instead the difference between a computed, estimated or measured value and the true, or theoretically correct, value.

Bias

• The Public: Willful manipulation of facts to suit a particular ideology or point of view.
• Scientists: A term used to describe a statistical sample in which members of the sample are not equally likely to be chosen. Also a term used to describe the difference between an estimator's expectation and the true value of the parameter being estimated. For some scientific analyses, a certain degree of bias can actually be beneficial.

Cross posted and adapted from NASA’s What on Earth blog. Adam is based at NASA’s Goddard Space Flight Center outside Washington, D.C.

Dr. Tony Freeman, Earth science manager at NASA's Jet Propulsion Laboratory, is in Copenhagen attending what is being billed as a historical climate summit. This is his final dispatch from the negotiations.

One very bright spot at the conference has been the U.S. presence. The U.S. Center was a very popular place for participants to visit, and I think nearly everyone with a camera phone took a picture of the “Science on a Sphere” globe hanging there (see my earlier entry). A few NASA presentations took place there, though I would have preferred to see NASA have an even stronger presence at the conference. However, the attendance of high-level members of our government sent a clear message of the U.S.’ seriousness of intent at the negotiations.

As the conference winds towards its conclusion, and the government ministers arrive, people’s expectations seem to be on the increase, as does the intensity of the demonstrations. Today we heard that the president of the conference had resigned, and that the prime minster of Denmark had taken her place. So will this U.N. summit result in an agreement? There are rumors flying that the answer is yes, with a possible implementation of reducing emissions from deforestation and degradation and a curb on emissions, though I suspect the result will be a compromise needing a lot of refinement in the future (like most political agreements).

--Tony Freeman