August 23, 2013
This distressing situation nonetheless presents scientists with an opportunity. Because the climate change is so widespread, it can be studied by examining a tremendous range data. Many of these data are collected from satellite images, extracted through analyzing ice cores or found from sifting through atmospheric temperature records. But some are collected from a bit more unorthodox sources. In no particular order, here’s our rundown of 5 unusual ways scientists are currently studying the changing climate:
1. Fossilized Urine
The hyrax—a small, herbivorous mammal native to Africa and the Middle East—has a pair of uncommon habits. The animals tend to inhabit the same cracks in rock for generations, and they also like to urinate in the exact same spot, over and over and over again. Because their urine contains traces of leaves, grasses and pollen, the layers of dried urine that build up and fossilize over thousands of years have given a team of scientists (led by Brian Chase of Montpellier University) a rare look at ancient plant biodiversity and how it’s been affected by broader changes in climate.
Further, the nitrogen in the urine—an element that’s long been important to those who utilize the scientific properties of pee—along with the urine’s carbon content tell an important story as layer after layer of the dessicated substance, called hyraceum, is analyzed. In drier times, plants are forced to incorporate heavier isotopes of these elements into their tissues, so urine layers that contain an abundance of heavy isotopes indicate that the hyrax relieved themselves after ingesting relatively parched plants. Stacked layers of the excretions thus allow scientists to track humidity through time.
“Once we have found a good layer of solid urine, we dig out samples and remove them for study,” Chase told The Guardian in an article about his unusual work. “We are taking the piss, quite literally—and it is proving to be a highly effective way to study how climate changes have affected local environments.” His team’s most valuable data set? One particular pile of fossilized urine that has been accreting for an estimated 55,000 years.
2. Old Naval Logbooks
Few people care more about the weather than sailors. Old Weather, a citizen science project, hopes to take advantage of that fact to better understand the daily weather of 100 years ago. As part of the project, anyone can create an account and manually transcribe the daily logbooks of 18th and 19th century vessels that sailed the Arctic and elsewhere.
The work is still in its beginning stages: So far, 26,717 pages of records from 17 different ships have been transcribed, with roughly 100,000 pages to go. Eventually, once enough data has been transcribed, scientists from around the world who are coordinating the project will use these ultra-detailed weather reports to paint a fuller picture of how microvariations in Arctic weather correspond with long-term climate trends.
Although there’s no pay offered, there’s the satisfaction of adding to our record on climate variations over the past few centuries. Plus, transcribe enough and you’ll get promoted from “cadet” to “lieutenant” to “captain.” Not bad for a modern day scrivener.
3. Satellite Speeds
Not long ago, a group of scientists who study how the atmosphere behaves at high altitudes noticed something strange about several satellites in orbit: They were consistently moving faster than calculations indicated they should. When they tried to figure out why, they discovered that the thermosphere—the uppermost layer of the atmosphere, starting roughly 50 miles up, through which many satellites glide—was slowly losing its thickness over time. Because the layer, made of up sparsely distributed gas molecules, was losing its bulk, the satellites were colliding with fewer molecules as they orbited and thus experienced less drag.
Why, though, was the thermosphere undergoing such change? It turned out that higher levels of carbon dioxide emitted at the surface were gradually drifting upwards into the thermosphere. At that altitude, the gas actually cools things down, because it absorbs energy from collisions with oxygen molecules and emits that stored energy into space as infrared radiation.
For years, scientists had assumed the carbon dioxide released from burning fossil fuels didn’t reach higher than about 20 miles above the Earth’s surface, but this research—the first to measure the concentrations of the gas this high up—showed that climate change can even affect our uppermost atmospheric layers. The group plans to look back and see how historical changes in satellite speeds might reflect carbon dioxide levels in the past. They will also continue to track satellite speeds and levels of carbon dioxide in the thermosphere to see how our aeronautical calculations might have to take climate change into account in the future.
4. Dog Sleds
Unlike many sorts of climate data, information on sea ice thickness can’t be directly collected by satellites—scientists instead infer thicknesses from satellite measurements of the ice’s height above sea level and a rough approximation of ice’s density. But getting true measurements of sea ice thicknesses must be done manually with sensors that send magnetic fields through the ice and pick up signals from the water below it—the fainter the signals, the thicker the ice. So our knowledge of real ice thicknesses is constrained to the locations where researchers have actually visited.
In 2008, when Scottish researcher Jeremy Wilkinson first traveled to Greenland to collect such measurements on ice thickness, his team interviewed dozens of local Inuit people who spoke about the difficulties thinner sea ice posed for their traditional mode of transportation, the dog sled. Soon afterward, Wilkinson got an idea. ”We saw the large number of dog teams that were on the ice everyday and the vast distances they covered. Then came the light bulb moment—why don’t we put sensors on these sleds?” he told NBC in 2011 when the idea was finally implemented.
Since then, his team has attached the sensors to the sleds owned by a few dozen volunteers. As the Inuits glide over the sea ice on their sleds, the instruments take a measurement of the ice’s thickness every second. His team has now deployed the sled-mounted sensors in each of the last three years to collect the data. The information collected not only helps scientists gauge the accuracy of thicknesses derived from orbiting satellites, but also helps climate scientists better understand how sea ice is locally responding to warmer temperatures as seasons and years change.
5. Narwhal-Mounted Sensors
Narwhals are renowned for their ability to dive to extreme depths: They’ve been measured going as far as 5,800 feet down, among the deepest dives of any marine mammal. Starting in 2006, NOAA researchers have used this ability to their advantage, by strapping sensors that measure temperature and depth to the animals and using the data to track Arctic water temperatures over time.
The strategy gives scientists access to areas of the Arctic ocean that are normally covered by ice during the winter—because the Narwhals’ dives, which can last as long as 25 minutes, often take them under areas of the water that are frozen on top—and is much less expensive than equipping a full icebreaker ship and crew to take measurements. Before using narwhals, temperatures of the Arctic waters at remote depths were inferred from long-term historical averages. Using the unorthodox method has helped NOAA document how these historical averages have underrepresented the extent to which Arctic waters are warming, particularly in Baffin Bay, the body of water between Greenland and Canada.
April 19, 2013
Last year, to celebrate the 42nd Earth Day, we took a look at 10 of the most surprising, disheartening, and exciting things we’d learned about our home planet in the previous year—a list that included discoveries about the role pesticides play in bee colony collapses, the various environmental stresses faced by the world’s oceans and the millions of unknown species are still out in the environment, waiting to be found.
This year, in time for Earth Day on Monday, we’ve done it again, putting together another list of 10 notable discoveries made by scientists since Earth Day 2012—a list that ranges from specific topics (a species of plant, a group of catfish) to broad (the core of planet Earth), and from the alarming (the consequences of climate change) to the awe-inspiring (Earth’s place in the universe).
1. Trash is accumulating everywhere, even in Antarctica. As we’ve explored the most remote stretches of the planet, we’ve consistently left behind a trail of one supply in particular: garbage. Even in Antarctica, a February study found (PDF), abandoned field huts and piles of trash are mounting. Meanwhile, in the fall, a new research expedition went to study the Great Pacific Garbage Patch, counting nearly 70,000 pieces of garbage over the course of a month at sea.
2. Climate change could erode the ozone layer. Until recently, atmospheric scientists viewed climate change and the disintegration of the ozone layer as entirely distinct problems. Then, in July, Harvard researcher Jim Anderson (who won a Smithsonian Ingenuity Award for his work) led a team that published the troubling finding that the two might be linked. Some warm summer storms, they discovered, can pull moisture up into the stratosphere, an atmospheric layer 6 miles up. Through a chain of chemical reactions, this moisture can lead to the disintegration of ozone, which is crucial for protecting us from ultraviolet (UV) radiation. Climate change, unfortunately, is projected to cause more of these sorts of storms.
3. This flower lives on exactly two cliffs in Spain. In September, Spanish scientists told us about one of the most astounding survival stories in the plant kingdom: Borderea chouardii, an extremely rare flowering plant that is found on only two adjacent cliffs in the Pyrenees. The species is believed to be a relic of the Tertiary Period, which ended more than 2 million years ago, and relies on several different local ant species to spread pollen between its two local populations.
4. Some catfish have learned to kill pigeons. In December, a group of French scientists revealed a phenomenon they’d carefully been observing over the previous year: a group of catfish in Southwestern France had learned how to leap onto shore, briefly strand themselves, and swim back into the water to consume their prey. With more than 2,000,000 Youtube views so far, this is clearly one of the year’s most widely enjoyed scientific discoveries.
5. Fracking for natural gas can trigger moderate earthquakes. Scientists have known for a while that whenever oil and gas are extracted from the ground at a large scale, seismic activity can be induced. Over the past few years, evidence has mounted that injecting water, sand and chemicals into bedrock to cause gas and oil to flow upward—a practice commonly known as fracking—can cause earthquakes by lubricating pre-existing faults in the ground. Initially, scientists found correlations between fracking sites and the number of small earthquakes in particular areas. Then, in March, other researchers found evidence that a medium-sized 2011 earthquake in Oklahoma(which registered a 5.7 on the moment magnitude scale) was likely caused by injecting wastewater into wells to extract oil.
6. Our planet’s inner core is more complicated than we thought. Despite decades of research, new data on the iron and nickel ball 3,100 miles beneath our feet continue to upset our assumptions about just how the earth’s core operates. A paper published last May showed that iron in the outer parts of the inner core is losing heat much more quickly than previously estimated
, suggesting that it might hold more radioactive energy than we’d assumed, or that novel and unknown chemical interactions are occurring. Ideas for directly probing the core are widely regarded as pipe dreams, so our only options remains studying it from afar, largely by monitoring seismic waves.
7. The world’s most intense natural color comes from an African fruit. When a team of researchers looked closely at the blue berries of Pollia condensata, a wild plant that grows in East Africa, they found something unexpected: it uses an uncommon structural coloration method to produce the most intense natural color ever measured. Instead of pigments, the fruit’s brilliant blue results from nanoscale-size cellulose strands layered in twisting shapes, which which interact with each other to scatter light in all directions.
8. Climate change will let ships cruise across the North Pole. Climate change is sure to create countless problems for many people around the world, but one specific group is likely to see a significant benefit from it: international shipping companies. A study published last month found that rising temperatures make it probable that during summertime, reinforced ice-breaking ships will be able to sail directly across the North Pole—an area currently covered by up to 65 feet of ice—by the year 2040. This dramatic shift will shorten shipping routes from North America and Europe to Asia.
9. One bacteria species conducts electricity. In October, a group of Danish researchers revealed that the seafloor mud of Aarhus’ harbor was coursing with electricity due to an unlikely source: mutlicellular bacteria that behave like tiny electrical cables. The organisms, the team found, built structures that traveled several centimeters down into the sediment and conduct measurable levels of electricity. The researchers speculate that this seemingly strange behavior is a byproduct of the way of the bacteria harvests energy from the nutrients buried in the soil.
10. Our Earth isn’t alone. Okay, this one might not technically be a discovery about Earth, but over the past year we have learned a tremendous amount about what our Earth isn’t: the only habitable planet in the visible universe. The pace of exoplanet detection has accelerated rapidly, with a total of 866 planets in other solar systems discovered so far. As our methods have become more refined, we’ve been able to detect smaller and smaller planets, and just yesterday, scientists finally discovered a pair of distant planets in the habitable zone of their stars that are relatively close in size to Earth, making it more likely than ever that we might have spied an alien planet that actually supports life.
March 31, 2013
You probably think of the Arctic as a cold, frozen tundra—home to lichen, polar bears and scattered herds of reindeer. In many places, this view would be accurate, but in a few relatively southern areas in Canada, Alaska and Russia, warming temperatures over the past few decades have allowed new types of plants, such as shrubs, to take root.
And by 2050—if current warming trends continue—we’ll see a dramatically different ecosystem across the Arctic, starting with something that’s largely unknown in the area currently: trees. According to research published today in Nature Climate Change, tree cover in the Arctic could increase by more than 50 percent over the next few decades.
The research team, which included scientists from a number of universities and was led by Richard Pearson of the American Museum of Natural History, made the calculation based off of current projections of how the Arctic’s climate will change by 2050. So far, temperatures in the region have risen about twice as fast as those for the planet as a whole.
They created a model that predicts which class of plants (various grasses, mosses, shrubs or trees) will grow given a particular temperature and precipitation range expected for the future; for each spot on a map of the Arctic, they fed in the 2050 projections. Doing this kind of vegetative modeling for the Arctic, they say, is relatively straightforward compared to doing it for somewhere like the tropics, because there are hard limits on the temperature and growing season length that given plant types can tolerate.
They found that tree cover will expand drastically, covering up to 52 percent more land area than currently, rising far north of the current tree line in Alaska and Canada. This new tree cover will mostly come at the expense of areas currently covered by shrubs, but shrubs will take over places now dominated by tundra plants (lichens and mosses), and some areas presently under ice will convert into tundra.
In effect, the area’s warming climate and lengthening growing season will shift all current vegetation zones to more northerly and colder regions. Already, these vegetation zones have shifted an average of five degrees of latitude over the past 30 years–in other words,
the vegetation in one spot resembles how a location five degrees south looked 30 years ago .
But by 2050, this shift will be even more dramatic—perhaps equaling 20 degrees of latitude—and a projected 48 to 69 percent of the Arctic’s vegetated areas will switch to a different class of plants. Some rare plant species could be at risk of extinction if they’re not able to migrate as quickly as the vegetation zones move.
Because plants are the base of any food chain, this conversion will have wide-ranging effects, both locally and elsewhere. “These impacts would extend far beyond the Arctic region,” Pearson said in a press statement. “For example, some species of birds seasonally migrate from lower latitudes and rely on finding particular polar habitats, such as open space for ground-nesting.” Their migrations patterns would presumably be altered by the growth of forests on what had been open tundra.
Most troubling, the conversion of white, snow-covered land to dark vegetation will further
affect the warming of the planet. Because darker colors absorb more radiation than the white of ice and snow, shifting large masses of land to a darker color is projected to further accelerate warming, creating a positive feedback loop: more warming leads to a greener Arctic, which leads to more warming.
Given all the other problems that the area is rapidly encountering as the climate changes—melting glaciers, increasing oil exploration and hybridizing bear species—it’s clear that the Arctic will be one of the most environmentally fragile regions of the planet over the coming century.
March 22, 2013
Scientists and science writers have created catchy monikers for hybrid species, much the way tabloid writers merge the names of celebrity couples (Kimye, Brangelina, anyone?). Lions and tigers make ligers. Narwhals meet beluga whales in the form of narlugas. And pizzlies and grolar bears are a cross between polar bears and grizzlies. In coming years, their creativity may get maxed out to meet an expected spike in the number of hybrids. A driving force? Climate change.
A new study published in the journal PLOS Genetics showed that there’s a historic precedent for cross-breeding among polar bears and brown bears–we’ll jump on the bandwagon and call them brolar bears. The researchers also asserted that such hybridization is currently occurring at an accelerated clip. As sea ice melts, polar bears are forced ashore to an Arctic habitat that’s increasingly hospitable to brown bears. There have been recent sightings in Canada of the resulting mixed-breed animals, which have coloring anomalies such as muddy-looking snouts and dark stripes down their backs, along with the big heads and humped backs typical of brown bears.
As it turns out, climate-change-induced hybridization extends well beyond bears. A 2010 study published in the journal Nature listed 34 possible and actual climate-change-induced hybridizations (PDF) of Arctic and near-Arctic marine mammals–a group that has maintained a relatively consistent number of chromosomes over time, making them particularly primed for hybridization. Here are some highlights from this list, along with some more recent discoveries.
In 2009, a bowhead-right-whale hybrid was spotted in the Bering Sea by the National Oceanic and Atmospheric Administration’s (NOAA) National Marine Mammal Laboratory. Right whales, which typically hail from the North Pacific and North Atlantic, will increasingly be migrating north into the Arctic Ocean, the domain of bowheads, as a result of climate change–and co-mingling their DNA. The authors of the Nature study determined that “[d]iminishing ice will encourage species overlap.”
The narluga has a very big head, according to the scientists who found one in West Greenland. Its snout and lower jaw were particularly burly, and its teeth shared some similarities with both narwhals and belugas. Both species, which form a whale family called monodontidae, live in the Arctic Ocean and hunters have reported seeing more whales of similar stature in the region.
Harbor and Dall’s porpoises have already been mixing it up off the coast of British Columbia, and given that harbor porpoises are likely to keep moving north from the temperate seas of the North Atlantic and North Pacific into the home waters of the Dall’s, the trend is expected to continue. (Click here to see rare photos of the hybrid porpoise.)
Scientists in Ontario, Canada, are investigating inter-breeding between southern and northern flying squirrels as the southern rodents push into northern habitats. The hybrid squirrels have the stature of the southern species and the belly coloring of the northern one. The video below details the research.
Hybrid species often suffer from infertility, but some of these cross-breeds are having success at procreating. For example, researchers recently discovered the offspring of a female pizzly and a male grizzly bear (a subspecies of the brown bear) in Canada’s Northwest Territories. Despite cases like these, scientists are debating whether all of this hybridization is healthy. “Is this going to be a problem for the long-term existence of parental species? Are they going to merge into one big hybrid population?” asked University of California, Berkeley evolutionary biologist Jim Patton in an interview.
In the case of inter-bred polar bears, the concern is that the changing climate will be more welcoming to brown bears, and that while inter-species mating at first might appear to be an adaptive technique for polar bears, it could end up spelling their demise in all ways except cellular structure–much the way Neanderthals were folded into the human gene pool thanks to early humans in Europe more than 47,000 years ago.
Rare and endangered species are particularly vulnerable to the pitfalls of hybridization, according to the authors of the Nature study. “As more isolated populations and species come into contact, they will mate, hybrids will form and rare species are likely to go extinct,” they wrote. “As the genomes of species become mixed, adaptive gene combinations will be lost.”
Such is likely the case with the narluga. Scientists determined the animal’s lack of a tusk is a liability because the tusk is a measure of the narwhal’s breeding prowess. And a pizzly living at a German zoo showed seal-hunting tendencies, but lacked the swimming prowess of polar bears.
As Patton pointed out, it will be many years until we know the full consequences of hybridization. “We’re only going to find out in hindsight,” he said. But that’s not a reason to be complacent, according to the Nature authors, who called for the monitoring of at-risk species. “The rapid disappearance of sea ice,” they wrote, “leaves little time to lose.”
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March 4, 2013
Rapidly melting ice has already remade shipping possibilities in the Arctic. Over the past decade, commercial use of the Northern Sea Route (the blue shipping lane along the northern coast of Russia in the map above) during late summer has become commonplace, dramatically shortening the journey from Europe to the Far East.
If present trends continue, though, the options for shipping goods across the Arctic will expand even more. According to a paper published today in the Proceedings of the National Academy of Sciences, by 2040, the legendary Northwest Passage (the shipping lane on the left side of the map, along the coast of Canada and Alaska) could be accessible during some summers to normal oceangoing ships without specially reinforced ice-breaking hulls. Most surprisingly, at times, reinforced polar icebreakers might even be able to plow straight across the North Pole, making the shortest possible journey across the Arctic.
All this is due to the fact that, over the past two decades, temperatures have risen even faster in the Arctic than the planet as a whole. Although the polar ice pack grows each winter and shrinks each summer, the overall trend has been a decrease in total ice cover, as seen in the video below. In the future, this will open up a window for reinforced ships to break through weaker ice, and for normal ships to cruise through ice-free corridors.
The new study, by Laurence Smith and Scott Stephenson of UCLA, uses existing climate models to examine how this trend will change Arctic shipping for the years 2040 to 2059. They looked at theoretical ice conditions under a pair of climate scenarios from the UN’s Intergovernmental Panel on Climate Change’s most recent report, one that assumed a medium-low level of greenhouse gas emissions going forward, and another that assumed a high level. They also explored the navigational possibilities for two different types of ships: Polar Class 6 ice-breaking ships and normal oceangoing vessels.
Their analysis found that in both scenarios, the Northern Sea Route—already navigable for reinforced vessels in late summer most years—will become wider, opening up for a greater number of months each summer and allowing for a greater geographical diversity in routes. The wider lane will enable ships to take routes further away from the Russian coast and closer to the North Pole, shortening the journey over the top of our planet, and will allow unreinforced ships to travel through without an ice-breaking escort.
Currently, the Northwest Passage is inaccessible for normal vessels, and has only been transited a handful of times by reinforced ice-breaking ships. Under both of the scenarios in the model, though, it becomes navigable to Polar Class 6 ships every summer. At times, it could even be open to unreinforced vessels as well—the study shows that, when multiple simulations were run in both medium-low and high levels of greenhouse gas emissions, open sailing was possible for 50 to 60 percent of the years studied.
Finally, the straight shot over the North Pole—a route that would currently take would-be captains through a sheet of ice as much as 65 feet thick in areas—could also become possible for Polar Class 6 ships in both scenarios, at least in warmer years. “Nobody’s ever talked about shipping over the top of the North Pole,” Smith said in a press statement. “This is an entirely unexpected possibility.”
The most striking part of the study might be that these dramatic changes occurred in simulations assuming both medium-low and high levels of emissions, and that the time period studied isn’t all that far away, beginning just 27 years from the present. “No matter which carbon emission scenario is considered, by mid-century we will have passed a crucial tipping point—sufficiently thin sea ice—enabling moderately capable icebreakers to go where they please,” Smith said.