Stop Soot, Black Carbon, and Global Warming – Earthjustice

[Music playing] Sometimes it’s the little things that can make big things happen. Fleas and the plague, atoms and nuclear bombs. Diminutive leaders in world history. [Man laughs] Soot is one of these little things. Soot also known as black carbon is released when you burn dung, coal, diesel fuel and wood. [Trunk horn] From Los Angeles to Mumbai, soot causes respiratory illnesses like lung cancer and asthma [Man coughs] and contributes to one point six million premature deaths every year. Mostly among the poor. And it gets worse. Atmospheric currents carry soot thousands of miles from where it is produced, to the Himalayas and the arctic. Black carbon being black, absorbs sunlight, so even a little soot on snow makes it melt faster. And when snow melts global sea levels rise, threatening our freshwater indigenous communities and polar bears who hunt on the arctic ice. [Fish squeaks] Climate Change has been a big thing for awhile and carbon dioxide has been it’s main cause. Scientists estimate that soot causes twenty five percent of human caused global warming.

It’s the second leading cause of arctic warming after carbon dioxide. Let’s not underestimate the impact of this tiny particle. But there’s good news, reducing black carbon maybe the fastest way to slow global warming. Buy time for the arctic. Yes even more so than changing a light blub. Since black carbon only stays in the atmosphere for a couple of weeks, reducing it will produce results immediately. Of course reducing soot alone won’t solve global warming, but solving our soot problem now will help buy time for the arctic and allow us to deal with the bigger problem of carbon dioxide. We have the cleaner industries, cook stoves, and diesel now we have to use them. In developed nations, we’ve significantly reduced our black carbon, but we still have much more to do. [car horn] We need to tighten our standards at home and invest in cleaner technologies in developing nations.

In a world going on seven billion people, you might feel rather little yourself. But if you urge the US government and the European Union to take the lead on black carbon reduction, you can make a big difference. Go to And help stop these little things from causing big trouble. [Music ends].

Walrus Flash Mob & 20 Years of Pot Research

[Intro] Every now and then, a story shows up on your Facebook page, your Tumblr dash, your Twitter feed that just doesn't go away, because people keep arguing about it. And arguments are fine, but they often tend not to reveal much in the way of data, or context. So with that in mind, SciShow wanted to weigh in on "The Great Walrus Haulout of 2014". You've seen the pictures, probably, taken last month by a government biologist who counted more than 35,000 Pacific walruses crowded together on Point Lay, a rocky barrier island off Alaska's northern coast. Depending on what online ecosystem you inhabit, you might have seen this picture shared as a grim sign of global warming, or from the opposite perspective, as a normal event that environmentalists have just hyped up. Well, let's start with what we know – walruses can't swim for very long periods like seals can, so they stop between feedings to rest on chunks of land or ice.

This is known as "hauling out" and it is a thing that walruses do, especially in late summer and early fall. What's interesting, and kind of weird about the Point Lay haulout, is that there are SO MANY walruses resting together at the same place – it may be the biggest ever recorded. And while it's been described as a walrus "flash mob", it is not nearly as fun as that. Many of these walruses are females with young calves, and having thousands of animals, some weighing more than a ton, in such close quarters can lead to battles over territory, accidental tramplings, and the fast spread of disease. In fact, deaths in these mass haulouts are common. Now many media reports have quoted scientists as saying that haulouts are getting bigger, and therefore more dangerous, because of global warming.

As sea ice melts, more walruses have to cluster together on land to rest. But there's also been a backlash among your climate-change-is-not-happening crowd which has pointed out – OFTEN IN ALL CAPS – that these things have been seen before. Well yeah, sort of. Most often the skeptics are citing a University of Alaska study from 1978 that estimated that some 35,000 hauled out en masse that year, but that was an estimate made after the walruses had moved on, gleaned mostly from how much land the walruses had disturbed, and how many dead were left behind. Since then, research into these events has become more regular and rigorous, and results over the past ten years do seem to reveal a pattern. The first large haulout on land was recorded in 2007, when 30,000 walruses were counted on beaches on the Russian side of the Bering Strait.

And according to the U.S. National Marine Fisheries Service, this coincided with a loss of sea ice in that part of the Arctic, that at the time, was unprecedented. Then, in 2010, 20,000 walruses hauled out near Point Lay, and the following year, 30,000 appeared in the same place. But these numbers haven't gone up every year – there were no huge haulouts in 2008 and 2012, for example – years when, according to the Feds, there was enough sea ice for all of the animals to rest on. So the likelihood is we're going to be seeing more of these events in the future, but the science behind them is more complicated that you can fit into one hundred and forty characters. Another thing people like to argue about that's also being researched more than ever? Cannabis. By some estimates marijuana is now almost as prevalent as tobacco in many countries, and on Monday, a new study from the University of Queensland laid out all of the research that has been done on marijuana over the past 20 years, listing everything scientists have learned, as well as what patterns they've observed but haven't been connected yet.

Among the conclusions, even through it's not chemically addictive like opiates, cannabis has been found to cause what's known as a Dependence Syndrome – a persistent psychological craving that can disrupt a person's thoughts and behavior. This was documented in about one of every ten pot smokers across various studies, but the risk was nearly twice as high – one in six – among adolescents. Also, results show that regular cannabis users have double the risk of experiencing symptoms of psychosis – a disorder often described as a loss of touch with reality, as well as schizophrenia – a condition that causes things like disorganized thinking, delusions, and hallucinations. Now, this doesn't mean that pot causes these conditions, but the data do suggest that people who are genetically predisposed to these disorders are more likely to have symptoms appear if they smoke often. Finally, there are some correlations that scientists have found while studying pot use among teens, but so far they haven't found any direct link between the drug and these observations.

Specifically, they found that adolescents who regularly use pot typically attain a lower level of total education, suffer from intellectual impairment, and are more likely to use other illicit drugs. Now, these are all things that could have a number of social causes like poverty, access to education, and family situations, so no causal link has been established at all. But me? We're talking about the health of my brain here, so I'm not taking any chances; it's the only one I got, and I like to think it's working great on its own. Thanks for watching SciShow News, brought to you by Audible – which is giving away a free audio book to SciShow viewers. You can go to, and download one of my favorite new science books of the year, "What If? Serious scientific answers to absurd hypothetical questions", narrated by my friend Wil Wheaton, and written by the creator of XKCD, Randall Munroe. Or, you know, practically any other book, for free, so go to


Flying over the melting arctic made climate change feel much more urgent

So I just landed in Tokyo. the one place where getting off the Metro, you can get lost in an underground mall. The flight from DC to here goes over Alaska and it flies over the Bering Sea which is just south of the Arctic Circle and I was going to the bathroom or something and I peeked out the window and I saw this vast amazing sight of a frozen ocean that was basically kind of breaking up and melting. And it made me so curious about ice! By every measure, what I was looking at out that window is a record. It's a record low of ice pack for the Arctic Ocean. We're talking like over the past past like several thousand years. Ok fine I'll go to unique love this Uniqlo This Uniqlo has row has 11 stories..

.12 stories So it turns out that ice is actually more important than you think. At least it was way more important than I thought. One of the more interesting functions that ice plays that it acts as a giant reflector basically bouncing a bunch of sunlight back up into space so that the earth doesn't have to absorb it. And this is actually super vital for keeping the earth systems regulated. The ice also keeps ocean currents running smoothly which a lot of species depend on including humans. Ice is more than just important for polar bears. It actually has huge ramifications for like our entire global ecosystem and all of the many systems that support I came to Tokyo for a totally different story. It has nothing to do with climate change I'm pretty sure jaywalking in Japan is like a total faux pax. Definitely. Everyone's laughing at me . The view I had while flying over Alaska was beautiful. But the story it tells is one of potential disaster for our globe. I'm actually in Japan working on a couple of really interesting videos.

I won't give any spoilers away but I'll give you a hint. It has to do with North Korea and with racist people..

NASA | Massive Phytoplankton Bloom Discovered Under Arctic Sea Ice

[ Bells ] Scientists have found a massive phytoplankton bloom growing beneath sea ice in the Arctic. The discovery, captured on video and shown here, stunned scientists, as an under-ice bloom of this size has never been seen anywhere on the planet. The bloom was spotted last summer by a team of scientists collecting field measurements for NASA's ICESCAPE mission, which explores the effects of climate change in the Arctic. Sampling took place at multiple sites along two tracks of ice-covered water in the Chukchi Sea, just north of Alaska. According to observations, the bloom extended for more than 60 miles from the ice edge into the sea ice pack and concentrated in the top layers of water near the ocean surface. Video footage taken below the sea ice at two different study sites contrasts the Arctic's typically barren and dark blue water with the emerald shades of green produced when teeming with phytoplankton. The blooms consisted mainly of diatoms — microscopic plants that make up the base of the marine food chain and require large amounts of sunlight to grow.

Scientists previously thought blooms were limited to ice-free expanses of open water, where sunlight isn't reflected by sea ice and prevented from entering the ocean. But thinning ice and an increase in melt ponds has allowed more sunlight to reach the water below the sea ice in recent years, which may account for the presence of these massive blooms. If such blooms are widespread, scientists will have to evaluate the impact of these carbon-consumers on the amount of carbon dioxide entering the ocean, and what that means for our changing climate. [ Beeps ] .

GLACIER: Dr. Piers Sellers on Climate Change and the Arctic

The Arctic is warming twice as fast as anywhere else on Earth. Its seemingly remote location in the north might lead some to believe that what happens in the Arctic stays in the Arctic. But that is not the case. The consequences of this region’s transformation are being felt by the entire world, not just the Arctic’s 4 million people. [TEXT: Dr. Piers Sellers, Climate Scientist, NASA/GSFC] And the most important action that we can take to slow Arctic warming over the long term is to substantially reduce our emissions of carbon dioxide, methane and other greenhouse gases. But it’s also important to address black carbon — and that’s the soot that’s produced by dirty vehicles, oil and gas wells, and wildfires, and is a strong contributor to global warming by itself. But additionally, when this soot settles on the Arctic snow and ice, it increases the amount of heat that is absorbed, which in turn melts the snow and ice faster.

Now, as the snow and ice melt, the darker land and water underneath the snow are uncovered and absorb more heat. This accelerates additional melting in the Arctic. In scientific terms, this is a positive feedback loop, and it explains why the Arctic is warming faster than anywhere else on Earth. The water from melting ice ends up in the ocean and contributes to sea-level rise. Glaciers that have endured since the last ice age are shrinking and adding to the rising sea levels that threaten coastal communities around the globe. And emerging science suggests that changes in the Arctic may be affecting the jet stream in the Northern Hemisphere, disrupting weather patterns far beyond the Arctic. Now Arctic communities are facing the full brunt of these changes. [TEXT: In Alaska, permafrost thaw could add up to $6.1 billion to current costs of maintaining public infrastructure over the next 20 years.

] Thawing permafrost is destroying infrastructure. Loss of sea ice has left communities vulnerable to coastal erosion and threatens the survival of a number of key species. These communities are losing the ecosystems they depend on for their survival — and the centuries-old traditions they’ve built around them. The good news is that we can do something about it — now. Low-carbon solutions are increasingly abundant and affordable. Around the globe, the price of solar and wind energy has plummeted in recent years, with more than half of new power generation in 2014 alone coming from renewable sources. And some firms are voluntarily eliminating flaring and methane leaks from their oil and gas operations. Science has informed the public and policy-makers about this environmental crisis. What is needed now is the initiative and courage to confront the problem head on. Our actions can protect or unravel the Arctic.

Concerted and deliberate action by the world’s leaders in politics, in industry and in science will be needed to prevent the loss of our Arctic heritage and reduce further damage to the climate system. The responsibility for dealing with this challenge is on all of us. [TEXT: The world needs to redirect to a low-carbon future.] [TEXT: A key opportunity for effective action comes this December in Paris at the international climate negotiations.] [TEXT: Paris isn’t the end of the road — more work remains.] [TEXT: To learn more about the Arctic visit:] [TEXT: Additional footage provided by: NASA’s Scientific Visualization Studio, Chasing Ice, and Ukpeaġvik Iñupiat Corporation.] [TEXT: Produced by the U.S. Department of State].

A New Forecast Model Gives Scientists a Longer View of Arctic Sea Ice

It’s always a challenge to predict each year how much Arctic sea ice coverage might change with the seasons. Now we have a new tool to make the summer forecast for sea ice minimums just a little bit better. NASA scientists can make a reasonable estimate of September’s sea ice extent as early as this March, with the predictions getting more reliable everyday. This new forecasting model uses real-time NASA satellite data of Arctic sea ice melt, so the predictions improve through late spring and early summer as they incorporate more information about the state of sea ice melt and distribution of open water across the Arctic Ocean. Although most forecast models focus on predicting the extent of sea ice across the entire Arctic, this model also produces reliable forecasts of sea ice in specific regions, like the seas north of Alaska, crucial information for people living in and moving through the region. Arctic sea ice plays an important role in regulating the planet’s climate, so predictions of sea ice extent can help us better understand how global temperatures might change.

Scientists can continue to train the model based on historical observations. In just a few weeks, the model will begin producing forecasts of Arctic sea ice extent for the coming September and will continue making improvements, as the annual sea ice minimum extent gets closer. .

Ice Race – The NORTHEAST PASSAGE – the dream of the new Marine Silk Road

fishing grounds in the Indian Ocean have been kidnapped by Somali pirates off the coast of Africa. There’s nothing we can do when faced with guns. When we came up on deck armed only with knives and axes, they were already on board. One was here, another was there. One on the deck, and another on top, at the bridge. So there was basically nothing we could do. What could we do against those guns? After that horrific incident, I fear sailing. But I came to know a good captain and his men, and they changed my mind, so I have gotten on board again. But I won’t go to the Indian Ocean again, no matter how much money I could make. One person standing on guard for an ally will make a thousand enemies fearful. One Korean warship, the Lee Sunshin, will make a thousand enemies tremble with fear. We will secure the safety of Korean ships in the Gulf of Aden. From the national security point of view, it is better to diversify energy sources, because if you depend on one region heavily, it makes you more vulnerable in times of crisis. We have to consider that. Also, I think that the amount of energy provided by the Middle East will decrease in the future.

And that’s the reason why we should try to find new energy sources we demand, like Russia or somewhere in Central Asia, or some other regions. We will endeavor to make everything the best. So, especially the vessel, it’s the first time. As I know, for a foreign vessel, it’s the first time to pass on this one route. Before, it was only Soviet vessels who had passed through this route, so for foreign vessels, it is the first time. In the near future (or, “Soon…”) it will be totally totally ice-free across the North Pole. And what I can say is, for the foreseeable future, at least in the next fifty years. So this standard that you mention is very important, and the standard, first of all, means that the ship will need to be able to go through ice (quite heavy ice), and it will need to be also capable of coping with drifting ice, packed ice, and it must also be taking special precautions for being able to maneuver to avoid, for example, icebergs, which can be very dangerous.

So not only on the construction (although the ship has to be looked at especially for operating in such waters), but also the operation and having adequate information about the ice formations and such. Then they went more to the north, and they discovered a new land. Spitsbergen, it’s now called. But Barents called it also Het Nieuwe Land, “the New Land.” And at that part they couldn’t find a way further to the north, and Willem Barents had the idea for going more to the east, northeast, North of Novaya Zemlya. Several countries claim partial ownership of the Arctic Ocean, but this is an issue for diplomats to resolve. In Russia there is a common expression, though it’s not quite a saying: “Those who can swim in the Arctic Ocean are its real owners.” What’s most important, we could say, is that we’re able to sail on the Arctic Ocean all year round. The Murmansk Port is the gateway to the north and an ice-free harbor.

Ships can freely come and go to the rest of the world through the year. Not only shippers from Murmansk but global carriers use the port. Not long ago, all the nuclear-powered icebreakers which explored the routes to the North Pole and the Northern Sea Route belonged to Murmansk shippers. We can say Murmansk is at the heart of the Northern Sea Route. When everything proceeds without obstacles, the shortest sea route from Russian to Canada and the US will be created, and it will pass through Murmansk. We thought in the beginning that the ship might need near the full power of 21,000 horsepower. But surprisingly, she could sail at less than 13,000 horsepower, with a speed of more than 6 knots in the severe ice to the west of Wiangel island. This I believe will not be the last expedition.

We have worked so well and achieved so much. We held an international conference in Oslo to report on what INSROP had discovered. Technically speaking, a North Pole marine route is not impossible. Since satellites can constantly monitor ice conditions, there isn’t any problem in the summer. But when we conducted research, it was clear we needed icebreakers in the winter. This sea route is very attractive because, compared to the route through the Suez Canal, it cuts the distance between Europe and Korea and Japan by up to forty percent. We have learned a lot from these projects. One of them was mentioned earlier. There’s no real benefit to using the Northern Sea Route throughout the year. But we use it in certain seasons, with summer being the most beneficial. We can use the route in winter, but ships can’t go very fast due to the ice. So now there are voices saying use the southern route only in the winter. As long as humans expect speed, safety, and eco-friendly services, this market will expand.

In a place where voyages were not possible due to heavy ice, new sea routes have been created. We need to get rid of our old way of thinking and collect accurate data on Arctic ice. Creation of a new route will make shipping companies realize that they can bring economic and environmental benefits at the same time. If all the parties related to the new route work together, the global market will grow. Traditional ships must follow icebreakers, which chop a path through the ice in front of them. But his icebreaker supertanker combines both functions in one ship. So the ship is able to break through the ice and carry freight at the same time. Best of luck to Pohang’s Yong-il Bay! We signed a memorandum of understanding with FESCO, the largest state-owned ocean carrier in Russia October 2008. Railroad construction has started at Yong-il Bay in Korea.

The railway network will begin in Korea, cross Siberia, and then connect with the TCR in China and the TMR in Mongolia, and go on to the TSR in Europe. That enables this new Port of Yong-il Bay to feed Busan Habor as a international terminal heading for North America and Europe, the distant places. Moreover, I expect the New international container habour of Young-il Bay would be very competitive when it finds its role as a foothold-port in the East Asia Once the Northern Sea Route is developed, it will bring financial benefits but will also raise some issues for countries using the route. Some issues will be ecological changes or environmental problems affecting the Arctic. If those countries that take responsibility for the Arctic share basic research on it, in the long run the Northern Sea Route will be environmentally sound and sustainable. It’s important that each country pay for its own contributions to basic research. That’s why the Araon to contribute to global society by conducting international co-research, to build up a basic infrastructure for Northern Sea Route research.

Thanks to global warming, the Northern Sea Route can open. As the ice melted, a new sea lane was created. It’s good that ships can travel over the North Pole, but climate change in the extreme north brought by global environmental change is not always good. Many Russian meteorologists and researchers from the Russian Academy of the Sciences are conducting research into the issue. The melting of ice in the Arctic is an environmental issue and it may cause many problems in the future. This is the Arctic Ocean. And you can see that we have waters coming from both the Pacific via Bering Strait, and the Atlantic through Fram Strait. And in the Canada Basin, these waters form layers, determined primarily by their salinity. It is important to people who live in Canada and other countries such as Korea, China, and Japan, who are also Pacific nations. We are affected by global change together. Before I sail out, I pray for the safety of the Korean and foreign seamen on board. I pray that we all come back in one piece.

I don’t expect any problems coming back home. That’s all I want. Piracy found in the Gulf of Aden, off the coast of Somalia, and in the Malacca Strait makes the Northern Sea Route more attractive. When the situation gets worse in the south, expectations for an alternative route will rise. Shipping companies will invest money and develop new ships suitable for voyages atop icy waters, instead of losing their ships and crew members in the south. I am sure that the current situation in the south is a primary factor influencing shipping companies to choose alternative routes or to give up on the southern route. Now the most significant change in the Canada Basin and the Arctic Ocean is the significant decrease in ice extent. You can see by the different colors where the ice edge was in 1980, 1997. But now in 2007, it’s a marked decrease. And this is affecting the waters north of Canada and Siberia. All the freezing land layers might melt away.

We might have to import bananas from Siberia instead of those from Africa. Is it fine for us to use melting ice? For example, let’s suppose that the ice in the Arctic Ocean melts down enough to create marine routes. It doesn’t melt anymore and global warming stops at the right moment. Let’s suppose that new marine routes open up. If these things happen, that would be a great thing for human beings. It is human wisdom that controls everything at just the right time. Such things don’t happen if we don’t take up a challenge with new things..

Earth in 1000 Years

Ice in its varied forms covers as much as 16% of Earth’s surface, including 33% of land areas at the height of the northern winter. Glaciers, sea ice, permafrost, ice sheets and snow play an important role in Earth’s climate. They reflect energy back to space, shape ocean currents, and spawn weather patterns. But there are signs that Earth’s great stores of ice are beginning to melt. To find out where Earth might be headed, scientists are drilling down into the ice, and scouring ancient sea beds, for evidence of past climate change. What are they learning about the fate of our planet, a thousand years into the future and even beyond? 30,000 years ago, Earth began a relentless descent into winter, Glaciers pushed into what were temperate zones. Ice spread beyond polar seas. New layers of ice accumulated on the vast frozen plateau of Greenland.

At three kilometers thick, Greenland’s ice sheet is a monumental formation built over successive ice ages and millions of years. It’s so heavy that it has pushed much of the island down below sea level. And yet, today, scientists have begun to wonder how resilient this ice sheet really is. Average global temperatures have risen about one degree Celsius since the industrial revolution. They could go up another degree by the end of this century. If Greenland’s ice sheet were to melt, sea levels would rise by over seven meters. That would destroy or threaten the homes and livelihoods of up to a quarter of the world’s population. These elevation maps show some of the areas at risk. Black and red are less than 10 meters above current sea level. The Southeastern United States, including Florida, And Louisiana.

Bangladesh. The Persian Gulf. Parts of Southeast Asia and China. That’s just the beginning. With so much at stake, scientists are monitoring Earth’s frozen zones, with satellites, radar flights, and expeditions to drill deep into ice sheets. And they are reconstructing past climates, looking for clues to where Earth might now be headed, not just centuries, but thousands of years in the future. Periods of melting and freezing, it turns out, are central events in our planet’s history. That’s been born out by evidence ranging from geological traces of past sea levels, the distribution of fossils, chemical traces that correspond to ocean temperatures, and more. Going back over two billion years, earth has experienced five major glacial or ice ages. The first, called the Huronian, has been linked to the rise of photosynthesis in primitive organisms. They began to take in carbon dioxide, an important greenhouse gas. That decreased the amount of solar energy trapped by the atmosphere, sending Earth into a deep freeze.

The second major ice age began 580 million years ago. It was so severe, it’s often referred to as “snowball earth.” The Andean-Saharan and the Karoo ice ages began 460 and 360 million years ago. Finally, there’s the Quaternary, from 2.6 million years ago to the present. Periods of cooling and warming have been spurred by a range of interlocking factors: volcanic events, the evolution of plants and animals, patterns of ocean circulation, the movement of continents. The world as we know it was beginning to take shape in the period from 90 to 50 million years ago. The continents were moving toward their present positions. The Americas separated from Europe and Africa. India headed toward a merger with Asia. The world was getting warmer.

Temperatures spiked roughly 55 million years ago, going up about 5 degrees Celsius in just a few thousand years. CO2 levels rose to about 1000 parts per million, compared to 280 in pre-industrial times, and 390 today. But the stage was set for a major cool down. The configuration of landmasses had cut the Arctic off from the wider oceans. That allowed a layer of fresh water to settle over it, and a sea plant called Azolla to spread widely. In a year, it can soak up as much as 6 tons of CO2 per acre. Plowing into Asia, the Indian subcontinent caused the mighty Himalayan Mountains to rise up. In a process called weathering, rainfall interacting with exposed rock began to draw more CO2 from the atmosphere, washing it into the sea. Temperatures steadily dropped.

By around 33 million years ago, South America had separated from Antarctica. Currents swirling around the continent isolated it from warm waters to the north. An ice sheet formed. In time, with temperatures and CO2 levels continuing to fall, the door was open for a more subtle climate driver. It was first described by the 19th century Serbian scientist, Milutin Milankovic. He saw that periodic variations in Earth’s rotational motion altered the amount of solar radiation striking the poles. In combination, every 100,000 years or so, these variations have sent earth into a period of cool temperatures and spreading ice. Each glacial period was followed by an interglacial period in which temperatures rose and the ice retreated. The Milankovic cycles are not strong enough by themselves to cause the shift.

What they do is get the ball rolling. A decrease in solar energy hitting the Arctic allows sea ice to form in winter and remain over summer, then to expand its reach the following year. The ice reflects more solar energy back to space. A colder ocean stores more CO2, which further dampens the greenhouse effect. Conversely, when ocean temperatures rise, more CO2 escapes into the atmosphere, where it traps more solar energy. With so many factors at play, each swing of the climate pendulum has produced its own unique conditions. Take, for example, the last interglacial, known as the Eemian, from 130 to 115,000 years ago. This happened at a time when CO2 was at preindustrial levels, and global temperatures had risen only modestly. But with higher solar energy striking the north, temperatures rose dramatically in the Arctic. The effect was amplified by the lower reflectivity of ice-free seas and spreading northern forests.

There is still uncertainty about how much these changes affected sea levels. Estimates range from a 5 to 9 meters, levels that would be catastrophic today. That’s one reason scientists today are intensively monitoring Earth’s frozen zones, including the ice sheet that covers Greenland. Satellite radar shows the flow of ice from the interior of the island and into glaciers. In the eastern part of the island, glaciers push slowly through complex coastal terrain. In areas of higher snowfall in the northwest and west, the ice speeds up by a factor 10. The landscape channels the ice into many small glaciers that flow straight down to the sea. In the distant past, the center of the island may have been drained by a giant canyon, recently discovered. Scientists found that it’s 550 kilometers long and up to 800 meters deep.

It leads from Greenland’s interior to one of today’s most volatile glaciers. This is the Petermann Glacier in Northwest Greenland. Amid unusually warm summer temperatures in 2012, satellites tracked a giant iceberg as it broke off and moved down the glacier’s outlet channel. At about 31 square kilometers, this island of ice stayed together as it floated along. After two months, it finally began to fragment. The Jakobshavn glacier on Greenland’s west coast flows toward the sea at a rapid rate of 20 to 40 meters per day. At the ice front, where the glacier meets the sea, Jakobshavn has been retreating as it dumps more and more ice into the ocean. You can see it in this map. In 1851, the front was down here. Now it’s 50 kilometers up. One reason, scientists say, is that water seeping down into its base is acting like a lubricant.

Another is that as the glacier thins, it’s more likely to break off, or calve, when it interacts with warmer ocean waters. Scientists are tracking the overall rate of ice loss with the Grace Satellite. They found that from 2003 to 2009, Greenland lost about a trillion tons, mostly along its coastlines. This number mirrors ice loss in the Arctic as a whole. By 2012, summer sea ice coverage had fallen to a little more than half of what it was in the year 1980. While the ice rebounded in 2013, the coverage was still well below the average of the last three decades. Analyzing global data from Grace, one study reports that Earth lost about 4,000 cubic kilometers of ice in the decade leading up to 2012. Sea levels around the world are now expected to rise about a meter by the end of the century. What will happen beyond that? To gauge the resilience of Greenland’s great ice sheet, scientists mounted one of the most intensive glacial drilling projects to date, the North Greenland Eemian Ice Drilling Project, or NEEM. The ice samples they obtained from the height of Eemian warming told a surprising story.

If you were a visitor to Northern Greenland in those times, you would have stood on ice over two kilometers thick. Temperatures were warmer than today by about 8 degrees Celsius. And yet, the ice had receded by only about 25%, a relatively modest amount. That has shifted the focus to Earth’s other, much larger ice sheet, on the continent of Antarctica. Antarctica contains 90% of all the ice, and 70% of all the fresh water on the Earth. Scientists are asking: how dynamic are its ice sheets? How sensitive are they to melting? Data from Grace and other satellites shows that this frozen continent overall has lately been losing as much ice as it gains. The vast plateau of Antarctic ice is one of the driest deserts on Earth. What little snow falls, remains, adding to the continent’s mass. You can see evidence of this in the snow and ice that piles up at the South Pole research station. This geodesic dome was built in the 1970s.

By the time it was decommissioned in 2009, the entrance was nearly buried. With a thickness of up to 4 kilometers, the ice on which this outpost sits will not melt easily. That’s true in part because of the landmass below it, captured in an extraordinary radar image. The eastern part of the continent, the far side of the image, is a stable foundation of continental crust. In contrast, the western side dips as much as 2500 meters below present day sea level. Along the Amundsen Sea Coast, the ice is disappearing at an accelerating rate. Inland ice streams are moving toward the ocean at at least 100 meters per year. They end up in floating ice shelves that extend hundreds of miles into the ocean. This region is the greatest source of uncertainty about global sea level projections. When ice shelves like this grow, they become prone to fracturing. A giant crack, for example, recently appeared in the Pine Island Glacier. Within two years, a 720 square kilometer iceberg had broken off.

But the scientists are more concerned about what’s happening below the surface. In recent times, the Southern ocean that swirls around the continent has been getting warmer, at the rate of .2 degrees Celsius per decade. That has affected ice shelves like Pine Island by melting them from below. In a comprehensive survey of the continent, scientists concluded that this process was responsible for 55 percent of the mass lost from ice shelves between 2003 and 2008. It’s also been blamed for one of the more puzzling twists in the story of climate change, the spread of sea ice all around Antarctica. One possibility is that ramped up winds, circling the pole, are pushing the ice into thicker, more resilient formations. Another is that the melting of ice shelves has spread a layer of cold, fresh water over coastal seas, which readily freezes.

A team of researchers has come to the Pine Island Glacier to try to monitor the melting in real time. After five years of preparation, they drilled through 500 meters of ice to begin measuring ice volume, temperature, salinity, and flow. In some places, they found melt rates of about 6 centimeters per day, or about 22 meters in a year. Because ice shelves hold back inland glaciers, the melting could trigger larger changes. That’s likely what happened to the Larsen ice shelf on the Antarctic Peninsula in the year 2002. It’s thought to have been stable since the last interglacial. Warmer ocean waters had been eating away at Larsen’s underside. By early February of 2002, the shelf began to splinter into countless small icebergs. By March 7th, when this picture was taken, it had completely collapsed, forming a vast slush that drifted out to sea. Without the shelf’s buttressing effect, a series of nearby glaciers picked up speed, dumping an additional 27 cubic kilometers of ice into the ocean per year.

Evidence from the last interglacial, the Eemian, brings an ominous warning of what could lie ahead. It’s based on the height of ancient coral reefs, which grow to a depth relative to the sea level above them. Based on reefs along the Australian coast, a recent study published in the journal Nature showed that sea levels remained stable for most of the Eemian, at 3-4 meters above those of today. But the authors found that in the last few thousand years of the period, starting around 118,000 years ago, sea levels suddenly shot up to 9 meters above today. The authors concluded, in their words, that “a critical ice sheet stability threshold was crossed, resulting in the catastrophic collapse of polar ice sheets.” Looking ahead, uncertainties about the future of our climate abound. According to one study, the long cool down to the next glacial period is due to start in the next 1500 years or so, based on the timing of Milankovic cycles. But for this actually to happen, the study says, enough new ice would have to form to get the ball rolling. CO2 would have to retreat to below pre-industrial levels.

Instead, it appears that a warming climate is becoming a fact of life. The danger is that if the melting gains a momentum of its own, even reducing CO2 emissions may not be enough to stop it. The still unfolding story of Earth’s past tells us about the mechanisms that can shape our climate. But it’s the unique conditions of our time that will determine sea levels, ice coverage, and temperatures. What’s at stake in the coming centuries is the world we know, the one that has nurtured and sustained us. The Earth itself will go on, ever changing on short and long time scales, a dynamic living planet 1.