May 23, 2013
Most people consider saving the Amazon rainforest a noble goal, but nothing comes without a cost. Cut down a rainforest, and the planet looses untold biodiversity along with ecosystem services like carbon dioxide absorption. Conserve that tract of forest, however, and risk facilitating malaria outbreaks in local communities, a recent study finds.
Nearly half of malaria deaths in the Americas occur in Brazil, and of those nearly all originate from the Amazon. Yet few conservationists consider the forest’s role in spreading that disease. Those researchers who do take malaria into account disagree on what role forest cover plays in its transmission.
Some think that living near a cleared patch of forest–which may be pockmarked with ditches that mosquitoes love to breed in–increase malaria incidence. Others find the opposite–that living near an intact forest fringe brings the highest risk for malaria. Still more find that close proximity to forests decrease malaria risk because the mosquitoes that carry the disease are kept in check through competition with mosquitoes that don’t carry the disease. Most of the studies conducted in the past only focused on small patches of land, however.
To get to the bottom of how rainforests contribute to malaria risk, two Duke University researchers collected 1.3 million positive malaria tests from a period of four-and-a-half years, and ranging over an area of 4.5 million square kilometers in Brazil. Using satellite imagery, they added information about the local environment where each of the cases occurred and also took rainfall into account, because precipitation affects mosquitoes’ breeding cycles. Using statistical models, they analyzed how malaria incidences, the environment and deforestation interacted.
Their results starkly point towards the rainforest as the main culprit for malaria outbreaks. “We find overwhelming evidence that areas with higher forest cover tend to be associated with higher malaria incidence whereas no clear pattern could be found for deforestation rates,” the authors write in the journal PLoS One. People living near forest cover had a 25-fold greater chance of catching malaria than those living near recently cleared land. Men tended to catch malaria more often the women, implying that forest related jobs and activities–traditionally carried out by men–are to blame by putting people at greater risk for catching the disease. Finally, the authors found that people living next to protected areas suffered the highest malaria incidence of all.
Extrapolating these results, the authors calculated that, if the Brazilian government avoids just 10 percent of projected deforestation in the coming years, citizens living near those spared forests will contend with a 2-fold increase in malaria by 2050. “We note that our finding directly contradicts the growing body of literature that suggests that forest conservation can decrease disease burden,” they write.
The authors of the malaria study do not propose, however, that we should mow down the Amazon in order to obliterate malaria. “One possible interpretation of our findings is that we are promoting deforestation,” they write. “This is not the case.” Instead, they argue that conservation plans should include malaria mitigation strategies. This could include building more malaria detection and treatment facilities, handing out bed nets and spraying for mosquitoes.
This interaction between deforestation and disease outbreakis just one example of the way efforts to protect the environment can cause nature and humans to come into conflict. Around the world, other researchers have discovered that conservation efforts sometimes produce negative effects for local communities. Lyme disease–once all but obliterated–reemerged with a vengeance (pdf) in the northeastern U.S. when abandoned farmland was allowed to turn back into forest. Human-wildlife conflict–including elephants tearing up crops, tigers attacking livestock, and wolves wandering into people’s backyards–often comes to a head when a once-declining or locally extinct species makes a comeback due to conservation efforts.
“We believe there are undoubtedly numerous ecosystem services from pristine environments,” the PLoS One authors conclude. “However, ecosystem disservices also exist and need to be acknowledged.”
May 2, 2013
In the wealthy world, improving the energy system generally means increasing the central supply of reliable, inexpensive and environmentally-friendly power and distributing it through the power grid. Across most of the planet, though, simply providing new energy sources to the millions who are without electricity and depend on burning wood or kerosene for heat and light would open up new opportunities.
With that in mind, engineers and designers have recently created a range of innovative devices that can increase the supply of safe, cheap energy on a user-by-user basis, bypassing the years it takes to extend the power grid to remote places and the resources needed to increase a country’s energy production capacity. Here are a few of the most promising technologies.
1. VOTO: Millions of people around the world use charcoal and wood-fueled stoves on a daily basis. VOTO (above), developed by the company Point Source Power, converts the energy these fires release as heat into electricity, which can power a handheld light, charge a phone or even charge a spare battery. The company initially designed VOTO for backpackers and campers in wealthy countries so they can charge their devices during trips, but is also trying to find a way to make it accessible to residents of the developing world for daily use.
2.Window Socket: This is perhaps the simplest solar charger in existence: Just stick it on a sunny window for 5 to 8 hours with the built-in suction cup, and the solar panels on the back will store about 10 hours worth of electricity that can be used with any device. If there’s no window available, a user can just leave it on any sunny surface, including the ground. Once it’s fully charged, it can be removed and taken anywhere—inside a building, stored around in a bag or carried around in a vehicle. The designers, Kyuho Song and Boa Oh of Yanko Design, created it to resemble a normal wall outlet as closely as possible, so it can be used intuitively without any special instructions.
3. The Berkeley-Darfur Stove: In the past few years, a number of health researchers have come to the same conclusion: that providing a safe, energy-efficient wood-burning cookstove to millions of people in the developing world can directly improve health (by reducing smoke inhalation), aid the environment (by reducing the amount of wood needed for fuel) and alleviate poverty (by reducing the amount of time needed to devote to gather wood every day).
Many projects have pursued this goal, but Potential Energy, a nonprofit dedicated to adapting and scaling technologies to help improve lives in the developing world, is the furthest along, having distributed more than 25,000 of their Berkeley-Darfur Stoves in Darfur and Ethiopia. Their stove’s design achieves these aims with features such as a tapered wind collar, a small fire box opening, nonaligned air vents that reduce the amount of wind allowed to stoke or snuff the fire (which wastes fuel) and ridges that ensure the optimal distance between the fire and pot in terms of fuel efficiency.
4. GravityLight: Along with wood-burning stoves, the kerosene-burning lamps that provide light throughout the developing world have recently become a target for replacement for one of the same reasons: The fumes generated by burning kerosene in closed corners are a major health problem. A seemingly simple solution is GravityLight, developed by the research initiative deciwatt.org.
To power the device, a user fills an included bag with about 20 pounds of rock or dirt, attaches it to the cord hanging down from the device and lifts it upward. The potential energy stored in that lifting motion is then gradually converted to electricity by the GravityLight, which slowly lets the bag downward over the course of about 30 minutes and powers a light or other electrical device during that time. It’s currently priced at about $10, and because it requires no running costs, the development team estimates that the investment will be paid back in about 3 months, as compared to the cost of kerosene.
5. SOCCKET: Soccer—known simply as football in nearly every English-speaking country besides the U.S.—is easily the most popular sport in the world. The newest product of Uncharted Play, a for-profit social enterprise, seeks to take advantage of the millions of people already playing the sport to replace kerosene lamps with electric light generated in a much different manner. Their ball uses an internal kinetically-powered pendulum to generate and store electricity. After about 30 minutes of play, the ball stores enough energy to power an attachable LED lamp for 3 hours. Development of the product was funded via Kickstarter, and the first ones will ship in the next few weeks. A percentage of all retail sales will go to providing SOCCKETs to schools in the developing world.
April 25, 2013
Penguins seem a bit out of place on land, with their stand-out black jackets and clumsy waddling. But once you see their grace in the water, you know that’s where they’re meant to be–they are well-adapted to life in the ocean.
1. Depending on which scientist you ask, there are 17–20 species of penguins alive today, all of which live in the southern half of the globe. The most northerly penguins are Galapagos penguins (Spheniscus mendiculus), which occasionally poke their heads north of the equator.
2. While they can’t fly through the air with their flippers, many penguin species take to the air when they leap from the water onto the ice. Just before taking flight, they release air bubbles from their feathers. This cuts the drag on their bodies, allowing them to double or triple their swimming speed quickly and launch into the air.
4. Penguins don’t wear tuxedos to make a fashion statement: it helps them be camouflaged while swimming. From above, their black backs blend into the dark ocean water and, from below, their white bellies match the bright surface lit by sunlight. This helps them avoid predators, such as leopard seals, and hunt for fish unseen.
5. The earliest known penguin fossil was found in 61.6 million-year old Antarctic rock, about 4-5 million years after the mass extinction that killed the dinosaurs. Waimanu manneringi stood upright and waddled like modern day penguins, but was likely more awkward in the water. Some fossil penguins were much larger than any penguin living today, reaching 4.5 feet tall!
6. Like other birds, penguins don’t have teeth. Instead, they have backward-facing fleshy spines that line the inside of their mouths. These help them guide their fishy meals down their throat.
7. Penguins are carnivores: they feed on fish, squid, crabs, krill and other seafood they catch while swimming. During the summer, an active, medium-sized penguin will eat about 2 pounds of food each day, but in the winter they’ll eat just a third of that.
8. Eating so much seafood means drinking a lot of saltwater, but penguins have a way to remove it. The supraorbital gland, located just above their eye, filters salt from their bloodstream, which is then excreted through the bill—or by sneezing! But this doesn’t mean they chug seawater to quench their thirst: penguins drink meltwater from pools and streams and eat snow for their hydration fix.
9. Another adaptive gland—the oil (also called preen) gland—produces waterproofing oil. Penguins spread this across their feathers to insulate their bodies and reduce friction when they glide through the water.
10. Once a year, penguins experience a catastrophic molt. (Yes, that’s the official term.) Most birds molt (lose feathers and regrow them) a few at a time throughout the year, but penguins lose them all at once. They can’t swim and fish without feathers, so they fatten themselves up beforehand to survive the 2–3 weeks it takes to replace them.
11. Feathers are quite important to penguins living around Antarctica during the winter. Emperor penguins (Aptenodytes forsteri) have the highest feather density of any bird, at 100 feathers per square inch. In fact, the surface feathers can get even colder than the surrounding air, helping to keep the penguin’s body stays warm.
12. All but two penguin species breed in large colonies for protection, ranging from 200 to hundreds of thousands of birds. (There’s safety in numbers!) But living in such tight living quarters leads to an abundance of penguin poop—so much that it stains the ice! The upside is that scientists can locate colonies from space just by looking for dark ice patches.
13. Climate change will likely affect different penguin species differently—but in the Antarctic, it appears that the loss of krill, a primary food source, is the main problem. In some areas with sea ice melt, krill density has decreased 80 percent since the 1970s, indirectly harming penguin populations. However, some colonies of Adelie penguins (Pygoscelis adeliae) have grown as the melting ice exposes more rocky nesting areas.
14. Of the 17 penguin species, the most endangered is New Zealand’s yellow-eyed penguin (Megadyptes antipodes): only around 4,000 birds survive in the wild today. But other species are in trouble, including the erect-crested penguin (Eudyptes sclateri) of New Zealand, which has lost approximately 70 percent of its population over the past 20 years, and the Galapagos penguin, which has lost more than 50 percent since the 1970s.
Learn more about the ocean from the Smithsonian’s Ocean Portal.
April 22, 2013
Over the past few decades, researchers have developed biofuels derived from an remarkable variety of organisms—soybeans, corn, algae, rice and even fungi. Whether synthesized into ethanol or biodiesel, though, all of these fuels suffer from the same limitation: They have to be refined and blended with heavy amounts of conventional, petroleum-based fuels to run in existing engines.
Though this is far from the only current problem with biofuels, a new approach by researchers from the University of Exeter in the UK appears to solve at least this particular issue with one fell swoop. As they write today in an article in Proceedings of the National Academy of Sciences, the team has genetically engineered E. coli bacteria to produce molecules that are interchangeable to the ones in diesel fuels already sold commercially. The products of this bacteria, if generated on a large-scale, could theoretically go directly into the millions of car and truck engines currently running on diesel worldwide—without the need to be blended with petroleum-based diesel.
The group, led by John Love, accomplished the feat by mixing and matching genes from several different bacteria species and inserting them into the E. coli used in the experiment. These genes each code for particular enzymes, so when the genes are inserted into the E. coli, the bacteria gains the ability to synthesize these enzymes. As a result, it also gains the ability to perform the same metabolic reactions that those enzymes perform in each of the donor bacteria species.
By carefully selecting and combining metabolic reactions, the researchers built an artificial chemical pathway piece-by-piece. Through this pathway, the genetically modified E. coli growing and reproducing in a petri dish filled with a high-fat broth were able to absorb fat molecules, convert them into hydrocarbons and excrete them as a waste product.
Hydrocarbons are the basis for all petroleum-based fuels, and the particular molecules they engineered the E. coli to produce are the same ones present in commercial diesel fuels. So far, they’ve only produced tiny quantities of this bacterial biodiesel, but if they were able to grow these bacteria on a massive scale and extract their hydrocarbon products, they’d have a ready-made diesel fuel. Of course, it remains to be seen whether fuel produced in this way will be able to compete in terms of cost with conventional diesel.
Additionally, energy never comes from thin air—and the energy contained within this bacterial fuel mostly originates in the broth of fatty acids that the bacteria are grown on. As a result, depending on the source of these fatty acids, this new fuel could be subject to some of the same criticisms leveled at biofuels currently in production.
For one, there’s the argument that converting food (whether corn, soybeans or other crops) into fuel causes ripple effects in global food market, increasing the volatility of food prices, as a UN study from last year found. Additionally, if the goal of developing new fuels is to fight climate change, many biofuels fall dramatically short, despite their environmentally-friendly image. Using ethanol made from corn (the most widely used biofuel in the U.S.), for example, is likely no better than burning conventional gasoline in terms of carbon emissions, and maybe actually be worse, due to all the energy that goes into growing the crop and processing it info fuel.
Whether this new bacteria-derived diesel suffers from these same problems largely depends upon what sort of fatty acid source is eventually used to grow the bacteria on a commercial scale—whether it would by synthesized from a potential food crop (say, corn or soy oil), or whether it could come from a presently-overlooked energy source. But the new approach already has one major advantage: Just the steps needed to refine other biofuels so they can be used in engines use energy and generate carbon emissions. By skipping these steps, the new bacterial biodiesel could be an energy efficient fuel choice from the start.
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.