Funnel cloud from Rio: Photos showing a funnel cloud seen around sunset, from Rio de Janeiro, Brazil. No tornado, storm or even rain was reported. More.
February 7, 2017 photo by Helio C. Vital in Rio.
Stacked moons: A stack of moon images from the morning of February 24, taken at 1 minute intervals as the moon rose from the horizon, by Ken Christison. More.
Image via Ken Christison
Artificial space clouds over U.S. East: NASA launched a sounding rocket on June 29 that formed colorful clouds in space, visible from New York to North Carolina. More.
Artificial clouds generated by rocket fired from Wallops Island, Virginia on June 29, 2017. Photo via Robert Williams. Read more.
Giant iceberg on the move: The calving of this iceberg in July reduced the size of Antarctica’s Larsen C ice shelf by 12 percent. More.
Giant iceberg breaking away from Larsen C ice shelf. Image via ESA.
Red sprite over Oklahoma: Photographer Paul Smith said he thinks this may be the 1st documented capture of a red sprite over Oklahoma. They’re large-scale electrical discharges – high above thunderstorm clouds – flickering in the night. More.
Red sprite over Oklahoma, caught by Paul Smith on October 6. Visit Dramatic sky photography by Paul Smith on Facebook.
Land of Terror: This looks like an abstract painting, but it’s a satellite image of the Tanezrouft Basin, a part of the Sahara Desert in central Algeria known as the Land of Terror. More.
This natural-color image, acquired on October 22, 2017, by NASA/s Landsat 8 satellite, shows concentric rings of exposed sandstone strata that create stunning patterns across the Tanezrouft Basin. Viewed from 705 kilometers (438 miles) above Earth. Image via NASA.
California in flames: According to the California Department of Forestry and Fire Protection, the 2017 California wildfire season is the worst on record. More.
This image was acquired via the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite on December 5. Image via NASA Earth Observatory.
… And we’ve had so many more great today’s images in 2017. You can see all of them here.
Bottom line: Favorite EarthSky images of 2017.
Funnel cloud from Rio: Photos showing a funnel cloud seen around sunset, from Rio de Janeiro, Brazil. No tornado, storm or even rain was reported. More.
February 7, 2017 photo by Helio C. Vital in Rio.
Stacked moons: A stack of moon images from the morning of February 24, taken at 1 minute intervals as the moon rose from the horizon, by Ken Christison. More.
Image via Ken Christison
Artificial space clouds over U.S. East: NASA launched a sounding rocket on June 29 that formed colorful clouds in space, visible from New York to North Carolina. More.
Artificial clouds generated by rocket fired from Wallops Island, Virginia on June 29, 2017. Photo via Robert Williams. Read more.
Giant iceberg on the move: The calving of this iceberg in July reduced the size of Antarctica’s Larsen C ice shelf by 12 percent. More.
Giant iceberg breaking away from Larsen C ice shelf. Image via ESA.
Red sprite over Oklahoma: Photographer Paul Smith said he thinks this may be the 1st documented capture of a red sprite over Oklahoma. They’re large-scale electrical discharges – high above thunderstorm clouds – flickering in the night. More.
Red sprite over Oklahoma, caught by Paul Smith on October 6. Visit Dramatic sky photography by Paul Smith on Facebook.
Land of Terror: This looks like an abstract painting, but it’s a satellite image of the Tanezrouft Basin, a part of the Sahara Desert in central Algeria known as the Land of Terror. More.
This natural-color image, acquired on October 22, 2017, by NASA/s Landsat 8 satellite, shows concentric rings of exposed sandstone strata that create stunning patterns across the Tanezrouft Basin. Viewed from 705 kilometers (438 miles) above Earth. Image via NASA.
California in flames: According to the California Department of Forestry and Fire Protection, the 2017 California wildfire season is the worst on record. More.
This image was acquired via the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite on December 5. Image via NASA Earth Observatory.
… And we’ve had so many more great today’s images in 2017. You can see all of them here.
Bottom line: Favorite EarthSky images of 2017.
The bright source near the bottom of this image, Sagittarius A* – pronounced Sagittarius A-star – is thought to be the location of the supermassive black hole at the center of our home galaxy, the Milky Way. See the filament appearing to point toward it? The filament might be caused by high-speed particles kicked away from the black hole, or it might be something even stranger. Image via NSF/ VLA/ UCLA/ M. Morris et al./ CfA.
One of the most mysterious and interesting known locations in our neighborhood of space is the center of our home galaxy, the Milky Way. It’s thought to contain a supermassive black hole, with a mass of some 4 million suns. Astronomers call this region and its possible black hole Sagittarius A* (aka Sgr A*, pronounced Sagittarius A-star). In 2016, Farhad Yusef-Zadeh of Northwestern University reported his discovery of an unusual filament in this region. The filament is about 2.3 light-years long and appears to curve around the site of the black hole. Now, another team of astronomers has employed a new technique to obtain a high-quality image of the curved filament. These astronomers said their new image supports the idea that the filament is pointing toward the black hole. The new image has led to some fascinating speculations as to the nature of this mystery filament.
A paper describing the new image – and astronomers ideas based upon it – was published in the December 1, 2017 issue of the peer-reviewed Astrophysical Journal Letters.
Mark Morris of the University of California, Los Angeles, led the imaging study. He said in a December 20, 2017 statement from the Harvard-Smithsonian Center for Astrophysics (CfA):
With our improved image, we can now follow this filament much closer to the galaxy’s central black hole, and it is now close enough to indicate to us that it must originate there. However, we still have more work to do to find out what the true nature of this filament is.
Artist’s concept of Milky Way galaxy, showing the locations of the central, supermassive black hole and our solar system. The entire galaxy is about 100,000 light-years across. Our sun lies about 26,000 light-years from the center. Image via ZMEScience.
Researchers have considered three possible explanations for the filament:
The first is that it is caused by high-speed particles kicked away from the supermassive black hole. A spinning black hole coupled with gas spiraling inwards can produce a rotating, vertical tower of magnetic field that approaches or even threads the event horizon, the point of no return for infalling matter. Within this tower, particles would be sped up and produce radio emission as they spiral around magnetic field lines and stream away from the black hole.
The second, more fantastic, possibility is that the filament is a cosmic string, theoretical, as-yet undetected objects that are long, extremely thin objects that carry mass and electric currents. Previously, theorists had predicted that cosmic strings, if they exist, would migrate to the centers of galaxies. If the string moves close enough to the central black hole it might be captured once a portion of the string crosses the event horizon.
The final option is that the position and the direction of the filament aligning with the black hole are merely coincidental superpositions, and there is no real association between the two. This would imply it is like dozens of other known filaments found farther away from the center of the galaxy. However, such a coincidence is quite unlikely to happen by chance.
Each of the scenarios being investigated would provide intriguing insight if proven true. The scientists’ statement continued:
For example, if the filament is caused by particles being ejected by Sgr A*, this would reveal important information about the magnetic field in this special environment, showing that it is smooth and orderly rather than chaotic.
The second option, the cosmic string, would provide the first evidence for a highly speculative idea with profound implications for understanding gravity, space-time and the Universe itself.
Evidence for the idea that particles are being magnetically kicked away from the black hole would come from observing that particles further away from Sgr A* are less energetic than those close in. A test for the cosmic string idea will capitalize on the prediction by theorists that the string should move at a high fraction of the speed of light. Follow-up observations with the VLA should be able to detect the corresponding shift in position of the filament.
Even if the filament is not physically tied to Sgr A*, the bend in the shape of this filament is still unusual. The bend coincides with, and could be caused by, a shock wave, akin to a sonic boom, where the blast wave from an exploded star is colliding with the powerful winds blowing away from massive stars surrounding the central black hole.
Co-author Miller Goss, from the National Radio Astronomy Observatory in Socorro, New Mexico, said:
We will keep hunting until we have a solid explanation for this object. And we are aiming to next produce even better, more revealing images.
Unannotated image of the great cosmic filament at the center of our Milky Way galaxy. This radio image is from the NSF’s Karl G. Jansky Very Large Array. Image via NSF/ VLA/ UCLA/ M. Morris et al./ CfA.
Bottom line: Astronomers have obtained a new image of the 2.3-light-year-long filament that curves around Sagittarius A*, the region of our galaxy thought to contain a supermassive black hole.
Source: A Nonthermal Radio Filament Connected to the Galactic Black Hole?
The bright source near the bottom of this image, Sagittarius A* – pronounced Sagittarius A-star – is thought to be the location of the supermassive black hole at the center of our home galaxy, the Milky Way. See the filament appearing to point toward it? The filament might be caused by high-speed particles kicked away from the black hole, or it might be something even stranger. Image via NSF/ VLA/ UCLA/ M. Morris et al./ CfA.
One of the most mysterious and interesting known locations in our neighborhood of space is the center of our home galaxy, the Milky Way. It’s thought to contain a supermassive black hole, with a mass of some 4 million suns. Astronomers call this region and its possible black hole Sagittarius A* (aka Sgr A*, pronounced Sagittarius A-star). In 2016, Farhad Yusef-Zadeh of Northwestern University reported his discovery of an unusual filament in this region. The filament is about 2.3 light-years long and appears to curve around the site of the black hole. Now, another team of astronomers has employed a new technique to obtain a high-quality image of the curved filament. These astronomers said their new image supports the idea that the filament is pointing toward the black hole. The new image has led to some fascinating speculations as to the nature of this mystery filament.
A paper describing the new image – and astronomers ideas based upon it – was published in the December 1, 2017 issue of the peer-reviewed Astrophysical Journal Letters.
Mark Morris of the University of California, Los Angeles, led the imaging study. He said in a December 20, 2017 statement from the Harvard-Smithsonian Center for Astrophysics (CfA):
With our improved image, we can now follow this filament much closer to the galaxy’s central black hole, and it is now close enough to indicate to us that it must originate there. However, we still have more work to do to find out what the true nature of this filament is.
Artist’s concept of Milky Way galaxy, showing the locations of the central, supermassive black hole and our solar system. The entire galaxy is about 100,000 light-years across. Our sun lies about 26,000 light-years from the center. Image via ZMEScience.
Researchers have considered three possible explanations for the filament:
The first is that it is caused by high-speed particles kicked away from the supermassive black hole. A spinning black hole coupled with gas spiraling inwards can produce a rotating, vertical tower of magnetic field that approaches or even threads the event horizon, the point of no return for infalling matter. Within this tower, particles would be sped up and produce radio emission as they spiral around magnetic field lines and stream away from the black hole.
The second, more fantastic, possibility is that the filament is a cosmic string, theoretical, as-yet undetected objects that are long, extremely thin objects that carry mass and electric currents. Previously, theorists had predicted that cosmic strings, if they exist, would migrate to the centers of galaxies. If the string moves close enough to the central black hole it might be captured once a portion of the string crosses the event horizon.
The final option is that the position and the direction of the filament aligning with the black hole are merely coincidental superpositions, and there is no real association between the two. This would imply it is like dozens of other known filaments found farther away from the center of the galaxy. However, such a coincidence is quite unlikely to happen by chance.
Each of the scenarios being investigated would provide intriguing insight if proven true. The scientists’ statement continued:
For example, if the filament is caused by particles being ejected by Sgr A*, this would reveal important information about the magnetic field in this special environment, showing that it is smooth and orderly rather than chaotic.
The second option, the cosmic string, would provide the first evidence for a highly speculative idea with profound implications for understanding gravity, space-time and the Universe itself.
Evidence for the idea that particles are being magnetically kicked away from the black hole would come from observing that particles further away from Sgr A* are less energetic than those close in. A test for the cosmic string idea will capitalize on the prediction by theorists that the string should move at a high fraction of the speed of light. Follow-up observations with the VLA should be able to detect the corresponding shift in position of the filament.
Even if the filament is not physically tied to Sgr A*, the bend in the shape of this filament is still unusual. The bend coincides with, and could be caused by, a shock wave, akin to a sonic boom, where the blast wave from an exploded star is colliding with the powerful winds blowing away from massive stars surrounding the central black hole.
Co-author Miller Goss, from the National Radio Astronomy Observatory in Socorro, New Mexico, said:
We will keep hunting until we have a solid explanation for this object. And we are aiming to next produce even better, more revealing images.
Unannotated image of the great cosmic filament at the center of our Milky Way galaxy. This radio image is from the NSF’s Karl G. Jansky Very Large Array. Image via NSF/ VLA/ UCLA/ M. Morris et al./ CfA.
Bottom line: Astronomers have obtained a new image of the 2.3-light-year-long filament that curves around Sagittarius A*, the region of our galaxy thought to contain a supermassive black hole.
Source: A Nonthermal Radio Filament Connected to the Galactic Black Hole?
According to a new study, dogs possess more brain power than cats. The study, published December 12, 2017 in the journal Frontiers in Neuroanatomy, counted the number of neurons or “little grey cells” in the cerebral cortexes of the brains of a number of animals, including cats and dogs. These cells are associated with thinking, planning and complex behavior – things considered hallmarks of intelligence. The study found that dogs possess significantly more of them than cats.
Suzana Herculano-Houzel, Associate Professor of Psychology and Biological Sciences at Vanderbilt University, developed the method for accurately measuring the number of neurons in animals’ brains. She said in a statement:
I believe the absolute number of neurons an animal has, especially in the cerebral cortex, determines the richness of their internal mental state and their ability to predict what is about to happen in their environment based on past experience.
In this study, we were interested in comparing different species of carnivorans to see how the numbers of neurons in their brains relate to the size of their brains, including a few favorite species including cats and dogs, lions and brown bears.
(Carnivora is a diverse order that consists of 280 species of mammals all of which have teeth and claws that allow them to eat other animals.)
As far as dogs and cats go, the study found that dogs have about 530 million cortical neurons while cats have about 250 million. By contrast, our human brains have 16 billion cortical neurons.
Is it a surprise that Herculano-Houzel describes herself as a dog person? She commented:
I’m 100 percent a dog person. But, with that disclaimer, our findings mean to me that dogs have the biological capability of doing much more complex and flexible things with their lives than cats can. At the least, we now have some biology that people can factor into their discussions about who’s smarter, cats or dogs.
Illustration showing the brains of six carnivores. Image via Suzana Herculano-Houzel/Vanderbilt.
The researchers analyzed the brains of one or two specimens from each of eight carnivoran species: ferret, mongoose, raccoon, cat, dog, hyena, lion and brown bear.
They found that the brain of a golden retriever has more neurons than a hyena, lion or brown bear, even though the bigger predators have brains up to three times as large. The bear is an extreme example. Its brain is 10 times larger than a cat’s, but has about the same number of neurons.
The analysis also discovered that the raccoon was an outlier—on the brainy side: It packs the same number of cortical neurons as a dog into a brain the size of a cat’s. Herculano-Houzel said:
Raccoons are not your typical carnivoran. They have a fairly small brain but they have as many neurons as you would expect to find in a primate … and that’s a lot of neurons.
image via PetsPajamas.
Bottom line: A new study that measures neurons in the brain says dogs are smarter than cats.
Read more from Vanderbilt University
According to a new study, dogs possess more brain power than cats. The study, published December 12, 2017 in the journal Frontiers in Neuroanatomy, counted the number of neurons or “little grey cells” in the cerebral cortexes of the brains of a number of animals, including cats and dogs. These cells are associated with thinking, planning and complex behavior – things considered hallmarks of intelligence. The study found that dogs possess significantly more of them than cats.
Suzana Herculano-Houzel, Associate Professor of Psychology and Biological Sciences at Vanderbilt University, developed the method for accurately measuring the number of neurons in animals’ brains. She said in a statement:
I believe the absolute number of neurons an animal has, especially in the cerebral cortex, determines the richness of their internal mental state and their ability to predict what is about to happen in their environment based on past experience.
In this study, we were interested in comparing different species of carnivorans to see how the numbers of neurons in their brains relate to the size of their brains, including a few favorite species including cats and dogs, lions and brown bears.
(Carnivora is a diverse order that consists of 280 species of mammals all of which have teeth and claws that allow them to eat other animals.)
As far as dogs and cats go, the study found that dogs have about 530 million cortical neurons while cats have about 250 million. By contrast, our human brains have 16 billion cortical neurons.
Is it a surprise that Herculano-Houzel describes herself as a dog person? She commented:
I’m 100 percent a dog person. But, with that disclaimer, our findings mean to me that dogs have the biological capability of doing much more complex and flexible things with their lives than cats can. At the least, we now have some biology that people can factor into their discussions about who’s smarter, cats or dogs.
Illustration showing the brains of six carnivores. Image via Suzana Herculano-Houzel/Vanderbilt.
The researchers analyzed the brains of one or two specimens from each of eight carnivoran species: ferret, mongoose, raccoon, cat, dog, hyena, lion and brown bear.
They found that the brain of a golden retriever has more neurons than a hyena, lion or brown bear, even though the bigger predators have brains up to three times as large. The bear is an extreme example. Its brain is 10 times larger than a cat’s, but has about the same number of neurons.
The analysis also discovered that the raccoon was an outlier—on the brainy side: It packs the same number of cortical neurons as a dog into a brain the size of a cat’s. Herculano-Houzel said:
Raccoons are not your typical carnivoran. They have a fairly small brain but they have as many neurons as you would expect to find in a primate … and that’s a lot of neurons.
image via PetsPajamas.
Bottom line: A new study that measures neurons in the brain says dogs are smarter than cats.
Read more from Vanderbilt University
View larger. | Bright meteors of 2017. All photos and image compilation by Eliot Herman.
Veteran meteor observer Eliot Herman in Tucson, Arizona has many nights of very clear night skies, plus an automatic camera set-up that he runs all night on the nights of major (and some minor) meteor showers. He has contributed many wonderful meteor images to EarthSky pages. The composite image above represents his best for each noteworthy shower in 2017. Eliot wrote on Flickr that this montage represents:
… bright meteors culled from over 100,000 images acquired throughout 2017 in Tucson, Arizona. Imaging occurred during a significant fraction of the nights in Tucson when the sky was dark (little moon) and/or clear. All images acquired with a Nikon D800/810 and a Sigma 8 mm fisheye for 15-second exposures and iso 2500 (bright sky) or 3200 (dark sky). The Geminids ended the year with the brightest and most amazing hour of meteors I have observed in my lifetime.
My lifetime brightest fireball from the Geminids: flic.kr/p/219SViM
and flic.kr/p/21tuvpJCamera set up: flic.kr/p/A4R18b
There are many sporadic meteors represented including some notable bright meteors. A few meteors captured are from minor showers not often imaged. Some meteor showers such as the Leonids and Taurids were not optimum this year due to the Moon but the Geminids made up for it all.
There were the occasional glitches in 2017, saving the camera from an unexpected thunderstorm and the irritation of a bird that insisted on landing on my camera lens on multiple bright moon nights.
Bird landing:
flic.kr/p/UxNFoaThunderstorm:
flic.kr/p/Wp4bHm
Thank you for all your photos, Eliot, and for this wonderful compilation!
Here is Eliot’s photo of a very bright Geminid fireball, which he captured on the morning of December 14, 2017, around 4 a.m. “The Geminids are good,” he reported that morning.
Bottom line: 2017 meteors over Tucson, Arizona.
View larger. | Bright meteors of 2017. All photos and image compilation by Eliot Herman.
Veteran meteor observer Eliot Herman in Tucson, Arizona has many nights of very clear night skies, plus an automatic camera set-up that he runs all night on the nights of major (and some minor) meteor showers. He has contributed many wonderful meteor images to EarthSky pages. The composite image above represents his best for each noteworthy shower in 2017. Eliot wrote on Flickr that this montage represents:
… bright meteors culled from over 100,000 images acquired throughout 2017 in Tucson, Arizona. Imaging occurred during a significant fraction of the nights in Tucson when the sky was dark (little moon) and/or clear. All images acquired with a Nikon D800/810 and a Sigma 8 mm fisheye for 15-second exposures and iso 2500 (bright sky) or 3200 (dark sky). The Geminids ended the year with the brightest and most amazing hour of meteors I have observed in my lifetime.
My lifetime brightest fireball from the Geminids: flic.kr/p/219SViM
and flic.kr/p/21tuvpJCamera set up: flic.kr/p/A4R18b
There are many sporadic meteors represented including some notable bright meteors. A few meteors captured are from minor showers not often imaged. Some meteor showers such as the Leonids and Taurids were not optimum this year due to the Moon but the Geminids made up for it all.
There were the occasional glitches in 2017, saving the camera from an unexpected thunderstorm and the irritation of a bird that insisted on landing on my camera lens on multiple bright moon nights.
Bird landing:
flic.kr/p/UxNFoaThunderstorm:
flic.kr/p/Wp4bHm
Thank you for all your photos, Eliot, and for this wonderful compilation!
Here is Eliot’s photo of a very bright Geminid fireball, which he captured on the morning of December 14, 2017, around 4 a.m. “The Geminids are good,” he reported that morning.
Bottom line: 2017 meteors over Tucson, Arizona.
Tonight, look for Bellatrix, the third-brightest star in Orion. Although often overlooked in contrast to Orion’s two brightest stars – Betelgeuse and Rigel – Bellatrix is a wonderful star. You can see it tonight, despite the evening moonlight.
Donate: Your support means the world to us
The classic book on star names is Richard Hinckley Allen’s Star Names: Their Lore and Meaning. The book suggests the Latin name Bellatrix means Female Warrior, and that some find that name odd since the original Arabic title translates as Conqueror. But women understand. Bellatrix represents Orion’s left shoulder. Although it appears only as the 22nd brightest star in our sky, in reality it’s a hot, blue giant some 240 light-years away.
Also look for the the star Saiph. The four stars Betelgeuse, Rigel, Bellatrix and Saiph form the familiar rectangle of Orion. The name Saiph comes from the Arabic name meaning the Sword of the Giant. Saiph is a blazing hot supergiant star 720 light-years away.
The constellation Orion takes center stage this month and rightly so. With so many bright stars, it’s one of the most prominent constellations in the sky. You’ll find Orion climbing over the eastern horizon around 7 to 8 p.m. local time.
Bottom line: Rigel and Betelgeuse are Orion’s brightest stars. We briefly describe 2 more bright stars in Orion, Bellatrix and Saiph.
EarthSky lunar calendars are cool! They make great gifts. Order now. Supplies limited.
Explore Richard Hinckley Allen’s book Star Names: Their Lore and Meaning
Tonight, look for Bellatrix, the third-brightest star in Orion. Although often overlooked in contrast to Orion’s two brightest stars – Betelgeuse and Rigel – Bellatrix is a wonderful star. You can see it tonight, despite the evening moonlight.
Donate: Your support means the world to us
The classic book on star names is Richard Hinckley Allen’s Star Names: Their Lore and Meaning. The book suggests the Latin name Bellatrix means Female Warrior, and that some find that name odd since the original Arabic title translates as Conqueror. But women understand. Bellatrix represents Orion’s left shoulder. Although it appears only as the 22nd brightest star in our sky, in reality it’s a hot, blue giant some 240 light-years away.
Also look for the the star Saiph. The four stars Betelgeuse, Rigel, Bellatrix and Saiph form the familiar rectangle of Orion. The name Saiph comes from the Arabic name meaning the Sword of the Giant. Saiph is a blazing hot supergiant star 720 light-years away.
The constellation Orion takes center stage this month and rightly so. With so many bright stars, it’s one of the most prominent constellations in the sky. You’ll find Orion climbing over the eastern horizon around 7 to 8 p.m. local time.
Bottom line: Rigel and Betelgeuse are Orion’s brightest stars. We briefly describe 2 more bright stars in Orion, Bellatrix and Saiph.
EarthSky lunar calendars are cool! They make great gifts. Order now. Supplies limited.
Explore Richard Hinckley Allen’s book Star Names: Their Lore and Meaning
In the recently released US Global Change Research Program Report, one of the chapters I was most interested in was about the changes we’ve observed in the world’s oceans. The oceans are really the key to the climate change issue, whether that be in quantifying how fast it’s happening or how much will happen in the future. As humans emit greenhouse gases (particularly carbon dioxide), we see some major changes that cannot be explained naturally.
The oceans are important because they act as a buffer; that is, they absorb much of the effects of greenhouse gases. In fact, the oceans absorb a lot of human carbon pollution. This is a big help for us because without the oceans, the climate would change much faster.
But in a certain way, the oceans are hurting us too. Since the oceans absorb so much of our carbon pollution and the resulting heat (93% of the extra heat), they turn a short-term problem into a long-term problem. Just like a fly wheel can be used to store rotating energy in a machine, the oceans store heat energy and chemical energy that can later manifest itself. The oceans also impact our psychology. The pollution we emit today will have effects for many years (partly because of the oceans). We cannot just stop emitting pollution and think this problem will immediately go away. We have to plan ahead. And, importantly, we have to stop emitting before most of the effects are evident.
I like to think of the Earth’s climate like a heavy train. A train cannot stop quickly; the brakes have to be applied far ahead of an obstacle. The ocean is our “climate train.”
Okay with that, what did this new report show? There were four key findings the authors cited. First, as I mentioned, they report that the oceans are absorbing almost all the heat from greenhouse gases. Over the past six decades, the amount of heat at all levels of the ocean has increased. This heating will continue into the future with approximately 5°F warming by the year 2100. This may not sound like much, but it is really enormous heating for water. When oceans warm, sea levels rise (warming water expands). Warm water also evaporates much faster to the air so that the atmosphere becomes more humid, resulting in more heavy rainfalls and flooding.
The figure below shows the changes in ocean heat (OHC) measured in Joules (a unit of energy).
Ocean heat content data. Illustration: USGCRP report, originally from Cheng et al., 2017
A second conclusion is that the heat may lead to major changes in the ocean currents. There is a really important flow of ocean waters called the Atlantic Meridional Overturning Circulation. It is a stream of water that passes from the warm tropics up toward Europe. Then the water gets cold and dense, sinks, and flows back towards the equator. This current is responsible for the warm wet weather in England, for example (compared with other locations with the same latitude). The report discusses a potential weakening of this current. If the current were to weaken (or stop altogether), there would be major effects to the weather in Europe and North America.
A third conclusion from the report is that the oceans are absorbing a lot of the human carbon pollution. For instance, the oceans currently absorb more than one-quarter of carbon from burning fossil fuels. One consequence of this is the oceans are becoming more acidic. The carbon dioxide is changing the ocean chemistry.
The simple way to think about this is to consider a soda. If you shake a soda and then open the soda, it will fuzz and bubble. This happens because sodas are carbonated beverages. When a soda fizzes, the carbon dioxide is leaving the liquid. What we are doing to the oceans is the reverse process. We are putting carbon dioxide into the ocean waters. Through various chemical processes, it makes the oceans more acidic and that matters for animals that make shells. For many of these animals – particularly those at the base of the food chain – acidic waters can dissolve shells or make them hard to form in the first place. This really matters because if the food chain collapses, then marine ecosystems and human society suffer.
In the recently released US Global Change Research Program Report, one of the chapters I was most interested in was about the changes we’ve observed in the world’s oceans. The oceans are really the key to the climate change issue, whether that be in quantifying how fast it’s happening or how much will happen in the future. As humans emit greenhouse gases (particularly carbon dioxide), we see some major changes that cannot be explained naturally.
The oceans are important because they act as a buffer; that is, they absorb much of the effects of greenhouse gases. In fact, the oceans absorb a lot of human carbon pollution. This is a big help for us because without the oceans, the climate would change much faster.
But in a certain way, the oceans are hurting us too. Since the oceans absorb so much of our carbon pollution and the resulting heat (93% of the extra heat), they turn a short-term problem into a long-term problem. Just like a fly wheel can be used to store rotating energy in a machine, the oceans store heat energy and chemical energy that can later manifest itself. The oceans also impact our psychology. The pollution we emit today will have effects for many years (partly because of the oceans). We cannot just stop emitting pollution and think this problem will immediately go away. We have to plan ahead. And, importantly, we have to stop emitting before most of the effects are evident.
I like to think of the Earth’s climate like a heavy train. A train cannot stop quickly; the brakes have to be applied far ahead of an obstacle. The ocean is our “climate train.”
Okay with that, what did this new report show? There were four key findings the authors cited. First, as I mentioned, they report that the oceans are absorbing almost all the heat from greenhouse gases. Over the past six decades, the amount of heat at all levels of the ocean has increased. This heating will continue into the future with approximately 5°F warming by the year 2100. This may not sound like much, but it is really enormous heating for water. When oceans warm, sea levels rise (warming water expands). Warm water also evaporates much faster to the air so that the atmosphere becomes more humid, resulting in more heavy rainfalls and flooding.
The figure below shows the changes in ocean heat (OHC) measured in Joules (a unit of energy).
Ocean heat content data. Illustration: USGCRP report, originally from Cheng et al., 2017
A second conclusion is that the heat may lead to major changes in the ocean currents. There is a really important flow of ocean waters called the Atlantic Meridional Overturning Circulation. It is a stream of water that passes from the warm tropics up toward Europe. Then the water gets cold and dense, sinks, and flows back towards the equator. This current is responsible for the warm wet weather in England, for example (compared with other locations with the same latitude). The report discusses a potential weakening of this current. If the current were to weaken (or stop altogether), there would be major effects to the weather in Europe and North America.
A third conclusion from the report is that the oceans are absorbing a lot of the human carbon pollution. For instance, the oceans currently absorb more than one-quarter of carbon from burning fossil fuels. One consequence of this is the oceans are becoming more acidic. The carbon dioxide is changing the ocean chemistry.
The simple way to think about this is to consider a soda. If you shake a soda and then open the soda, it will fuzz and bubble. This happens because sodas are carbonated beverages. When a soda fizzes, the carbon dioxide is leaving the liquid. What we are doing to the oceans is the reverse process. We are putting carbon dioxide into the ocean waters. Through various chemical processes, it makes the oceans more acidic and that matters for animals that make shells. For many of these animals – particularly those at the base of the food chain – acidic waters can dissolve shells or make them hard to form in the first place. This really matters because if the food chain collapses, then marine ecosystems and human society suffer.
