Posts Tagged ‘environment’

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by IRIS KULBATSKI

Consuming a mixture of sugar syrup and glyphosate, the active ingredient in Monsanto’s Roundup herbicide, alters honey bees’ microbiomes, and these changes increased mortality among insects exposed to pathogenic bacteria, according to a study published yesterday (September 24) in PNAS.

Glyphosate is the most commonly used herbicide worldwide. It acts by blocking a key plant enzyme used in the production of amino acids. Researchers are divided on whether the chemical is safe to animals at the levels it is usually used as a herbicide. However, some bacteria are known to produce this enzyme, and the new study demonstrates what some researchers have suspected: glyphosate may harm animals indirectly by killing their resident microbes.

Nancy Moran of the University of Texas at Austin and colleagues found that glyphosate consumption can lower the levels of the common bee symbiont Snodgrassella alvi by up to five times in the guts of honey bees, and high levels of the herbicide thwarted growth of S. alvi in vitro. Moreover, bees were more susceptible to infection by Serratia marcescens, a bacterium commonly present at low levels in beehives, after drinking the glyphosate–sugar water cocktail: only 12 percent of the insects survived, compared with 47 percent of infected bees that had not been fed glyphosate.

Given these findings, more research is warranted to determine whether the proposed mechanism of honey bee morbidity contributes significantly to issues of colony collapse and overall rates of honey bee decline worldwide, University of Illinois bee geneticist Gene Robinson tells Science.

Moreover, the current study raises the possibility that glyphosate may alter the gut microbiome of other animals, including humans, Moran tells Science.

https://www.the-scientist.com/news-opinion/herbicide-may-harm-microbiome-of-bees-64860?utm_campaign=TS_DAILY%20NEWSLETTER_2018&utm_source=hs_email&utm_medium=email&utm_content=66214269&_hsenc=p2ANqtz–RVJMklVdDEAWS-ddB7O5kVzSQTWCLWqUOnn8jMfmpot3jBytURnj14l3Nx2fPlFTeNO-ZlmSqqln8Wjtd9SqOUpzqTQ&_hsmi=66214269

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After passing legislation 6 years ago that prohibited North Carolina policymakers from considering climate change data in planning for rising sea levels along their coast, Hurricane Florence now threatens to cause a devastating storm surge that could put thousands of lives in danger and cost North Carolina billions of dollars worth of damage.

The hurricane, which is expected to make landfall on Friday, is shaping up to be one of the worst storms to hit the East Coast. Residents of North Carolina’s Outer Banks and mainland coasts have already been ordered to evacuate. President Donald Trump declared a state of emergency in both North and South Carolina, and a Federal Emergency Management Agency administrator said that the Category 4 hurricane will likely cause “massive damage to our country.”

And the rise in sea levels, experts say, is making the storm surge worse.

Sea level rise is a direct consequence of global warming; the warming of the ocean has resulted in thermal expansion and melted ice sheets and glaciers that are causing the oceans to rise. Since 1950, the sea level has risen 6.5 inches ― a number that sounds small but has actually had major consequences across the country.

“Sea level rising, simply put, makes every coastal flood deeper and more destructive,” said Ben Strauss, CEO of Climate Central, a climate change research organization that has published dozens of studies about rising sea levels and the risks of ignoring the problem. “Ignoring it is incredibly dangerous.”

“It only takes a few extra inches of water depth to be the difference between a ruined floor and no damage, or a ruined electrical system and just a ruined floor,” Strauss said. “Floods tend to be a great deal more destructive and costly than homeowners anticipate.”

Sea level rise can also affect the severity of hurricanes, said William Sweet, an oceanographer at the National Oceanic and Atmospheric Administration. “If you compared storm surge heights from the same storm at the same location over several decades, the surge would be higher ― assuming no change in flood defenses ― because of sea level rise,” Sweet said.

But in North Carolina, lawmakers chose to ignore the threats. A panel of scientists on the state Coastal Resources Commission issued a dire warning in March 2010, estimating that the sea levels along the state’s coast would rise 39 inches over the next century. Conservative lawmakers and business interest groups feared the report would hurt lucrative real estate development on the state’s coast and sought to undermine it. A lobbying group committed to economic development on the coast accused the panel of “pulling data out of their hip pocket.”

Conservative state Rep. Pat McElraft, whose top campaign contributors were the North Carolina Association of Realtors and the North Carolina Home Builders’ Association, drafted a bill in response that rejected the panel’s predictions.

McElraft introduced the bill in April 2011, and it passed the legislature in the summer of 2012.

Part of the bill stipulated that state and local agencies must also refer to historical linear predictions of sea level rise rather than current research, and another alarming section required that research look only at 30-year predictions rather than at a century, as the CRC report had done. Supporters of the bill saw short-term benefits in more affordable insurance, and continued opportunities for real estate development and tourism along the attractive coast. Critics saw the long-term consequences of damaged homes and businesses and vast swaths of the state being swallowed by floods.

Environmental scientists, coastal researchers and a number of lawmakers called the measure a blatant denial of crucial climate science and criticized then-Gov. Bev Perdue (D) for not acting on the bill and therefore allowing it to become law.

“By putting our heads in the sand, literally, we are not helping property owners,” said then-state Sen. Deborah K. Ross. “We are hurting them. We are not giving them information they might need to protect their property. Ignorance is not bliss. It’s dangerous.”

‘It’s a really bad setup’

In North Carolina, the state’s topography and the rising sea levels have made for even more dangerous storms and floods, Strauss said. Unlike coastal communities that have deep, cliff-like dropoffs, North Carolina’s coast is flat, wide and shallow, “like a kiddie pool,” Strauss said. “When you think about storm surge, some places have higher potential than others. The same storm would produce different surges depending on the topography,” said Strauss.

The state also has a wide, shallow continental shelf compared with places like Miami, which “means there is massive potential for a storm surge,” he said.

“Especially a storm like this, that’s moving straight forward,” he said. “It’s a really bad setup.”

At the same time, climate change has “supercharged” recent storms, as HuffPost’s Chris D’Angelo reported on Friday, putting Florence on track to do as much, if not more, damage than last year’s Hurricane Harvey, which devastated parts of Texas and Louisiana.

“It is fair to say that the very same factors are likely at play here, namely very warm ocean temperatures and an anomalous jet stream pattern favoring stalled weather systems,” said Michael Mann, a climate scientist at Pennsylvania State University.

https://www.huffingtonpost.com/entry/north-carolina-sea-level-rise-hurricane-florence_us_5b985a87e4b0162f4731da0e?ncid=APPLENEWS00001

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A nearly 2,000-foot-long tube is towed offshore from San Francisco Bay on Saturday. It’s a giant garbage collector and the brainchild of 24-year-old Boyan Slat, who aims to remove 90 percent of ocean plastic by 2040.

by LAUREL WAMSLEY

We humans have deposited a huge amount of plastic in Earth’s waters. There are now five garbage-filled gyres in the world’s oceans — the largest and most notorious being the Great Pacific Garbage Patch, with its estimated 1.8 trillion pieces of plastic, spread across an area twice the size of Texas.

One of the people trying to figure out how to clean up the ocean is Boyan Slat, a 24-year-old Dutch social entrepreneur who has been working to invent a solution since he was 17. His idea — for a giant floating system that would corral the plastic so it can be scooped out — is on the verge of reality.

He founded a nonprofit called The Ocean Cleanup and picked up a major environmental award from the United Nations along the way. Tech investors including Peter Thiel and Marc Benioff got behind his go-big ethos; a reported $35 million total has been raised.

On Saturday, a vessel that usually tows oil rigs instead towed Slat’s giant garbage-catcher some 300 miles offshore from San Francisco Bay. For two weeks, engineers will monitor how the system handles the battering waves in the Pacific before towing it 1,100 more miles to the patch.

The system’s centerpiece is a nearly 2,000-foot-long plastic tube with a 10-foot skirt attached beneath, forming a U-shaped barrier designed to be propelled by wind and waves. Its aim is to collect plastic as it floats — and then every few months, a support vessel would come by to retrieve the plastic, like an oceanic garbage truck. The plastic would then be transported back to land for recycling.

If it works, The Ocean Cleanup plans to deploy a fleet of 60 such devices, which the group projects can remove half the plastic in the Great Pacific Garbage Patch in five years’ time.

But will it actually work? Slat doesn’t know.

His team has changed its concept over time, switching from a moored system to a drifting one, in order to act more like the plastic it’s trying to catch. They tested a prototype on the North Sea but say the Pacific will be the real challenge.

“We believe that every risk that we can eliminate in advance we have been able to eliminate,” he said in a video prior to Saturday’s launch. “But that doesn’t mean that all risks have been eliminated. Truly, the only way to prove that we can rid the oceans of plastic is to actually go out there and deploy the world’s first ocean-cleaning system.”

The Ocean Cleanup hopes to reduce the amount of plastics in the world’s oceans by at least 90 percent by 2040. But many experts on plastic pollution have expressed concerns about whether the project will be effective.

For one thing, most of the plastic that ends up in the ocean doesn’t end up in these garbage gyres.

“Based on the latest math, we think that about 8 million metric tons of plastic is flowing in to the ocean from land around the world,” says George Leonard, chief scientist at Ocean Conservancy. And he says that only around 3 percent to 5 percent of that total amount of plastic actually winds up in the gyres.

“So if you want to clean up the ocean,” Leonard says, “it may in fact be that the open ocean is not the place to look.”

Part of the issue is that not all plastic is buoyant. A lot of it sinks immediately — and thus won’t be captured by this floating boom, said Eben Schwartz, marine debris program manager for the California Coastal Commission.

“It would be wonderful if we can clean up the surface of the gyre, but since so much more of the trash in the ocean actually doesn’t end up on the surface of the gyre, it’s even more critical that we address where it’s coming from and try to stop it at its source,” Schwartz recently told NPR’s Here and Now.

Then there’s the question of whether the project might cause unintended environmental consequences. Specifically: Can you capture plastics without ensnaring marine life?

“We know from the fishing industry that if you put any kind of structure in the open ocean, it will attract a whole community of animals, both large and small, to that particular piece of structure,” Leonard says.

Fishermen sometimes create fish aggregating devices (FADs) that intentionally create little floating ecosystems to attract fish. “There’s a worry that this could become a very large FAD and attract a whole number of larger fish and marine mammals and seabirds that might be impacted by it,” he says.

Plus, The Ocean Cleanup’s system is made of high-density polyethylene, a kind of plastic. So, what if it becomes part of the problem it’s trying to solve?

“I sort of wonder what kinds of microplastics this thing is going to be generating on its own, assuming that it’s even functioning exactly as designed,” oceanographer Kara Lavender Law of the Sea Education Association told Wired. And if the boom gets busted in a big storm, well: “If it’s shedding nano-size particles and then gets smashed into 200-meter-long pieces, you’re really covering the whole size range there.”

And then there’s the worry that a big, expensive project like The Ocean Cleanup diverts money and attention away from other efforts that are known to be effective — such as waste management policies to keep the garbage from getting into the ocean in the first place.

A 2015 study found that China, Indonesia, the Philippines, Vietnam, Sri Lanka and Thailand were the leading sources of plastic waste in the world’s oceans.

“The science points to about a half a dozen countries in Southeast Asia which are rapidly developing economies that are heavily reliant on plastic, and lack the kind of waste management infrastructure that I think many of us in the U.S. take for granted,” Leonard says.

He points to one low-tech way to help fight plastics in the ocean: Pick up trash in your own local waterways. His organization’s annual International Coastal Cleanup takes place Sept. 15, when he says nearly a million people are expected to work to remove some 20 million pounds of trash from beaches and waterways around the world.

Leonard says the Ocean Conservancy is skeptical that the giant trash collector will work, “but we’re being enthusiastic, and we hope it does.”

“The ocean really needs all the help it can get.”

https://www.npr.org/2018/09/11/646724291/a-massive-floating-boom-is-supposed-to-clean-up-the-pacific-can-it-work

By Sarah Fecht

You’ve probably heard the news that our nation’s bees are in trouble. Pollinators have been disappearing for decades, and the population crash could threaten the global food supply. Now, a small city in Iowa has decided to do something about it.

This spring, Cedar Rapids (population: 130,000) will seed 188 acres with native prairie grasses and wildflowers. The city’s plan is to eventually create 1,000 acres of bee paradise by planting these pollinator-friendly foodstuffs.

Scientists think the pollinator crisis is caused by a variety of factors, including pesticides, pathogens, and climate change. Meanwhile, with farms, parking lots, mowed lawns, and other human developments replacing wildflower fields, bees have been losing habitat and their food supply. While many of the drivers behind bee population decline remain mysterious, the people of Cedar Rapids hope to at least give pollinators places to perch and plants to feed on.

The 1,000 Acre Pollinator Initiative (http://www.cedar-rapids.org/residents/parks_and_recreation/pollinator_and_natural_resources_initiatives.php#Acre) grew out of a partnership with the Monarch Research Project(MRP), whose goal is to restore monarch butterfly populations. It was Cedar Rapids Park Superintendent Daniel Gibbins who proposed converting 1,000 acres into pollinator habitat over five years. So far, the project has secured $180,000 in funding from the state and the MRP.

“With the agricultural boom around 100 years ago, about 99.9 percent of all the native habitat of Iowa has been lost,” says Gibbins, who is spearheading the project. “When you convert it back to what was originally native Iowa, you’re going to help a lot more than just native pollinators. You’re helping birds, amphibians, reptiles, mammals—everything that’s native here relies on native vegetation.”

Prairie revival

Cedar Rapids has developed a special mix of grasses and wildflowers to help restore that native habitat. The seed mix includes 39 species of wildflowers, and 7 species of native prairie grasses. While bees and butterflies are mostly attracted to the flowers, the hardy prairie grasses will prevent weeds and invasive species from moving in and choking out the flowers.

Gibbins and his team have catalogued all the unused public land where they could potentially plant the flowers and grasses. The list includes not only the rarely frequented corners of parks, golf courses, and the local airport, but also sewage ditches, water retention basins, and roadway right-of-ways, totaling nearly 500 acres. Cedar Rapids is working with other cities within the county to reach its 1,000-acre target.

Before they can seed the land with the special pollinator plant mix, Gibbins’ crew has to “knock back the undesirable vegetation.” That means mowing down, burning off, or in some cases applying herbicide to get rid of grass, weeds, and invasive species. They’ll lay down the special seed mixture in the spring and fall.

“You can’t just seed them and walk away,” says Gibbins. Although the pollinator habitat will be lower maintenance than a green turf that needs to be mown every week, the prairie grasses will require some care, including mowing once a year or burning every few years.

Everyone can help

You don’t need to have 1,000 spare acres to help bees and butterflies. Even devoting a few square feet of your garden—or even a few small planters—to wildflowers native to your area could make a difference, says Gibbins.

“When creating pollinator gardens, the most important thing is to have a big diversity of wildflowers and heirloom crops that bloom in the spring, summer, and fall,” says Stephen Buchmann, a pollination ecologist at the University of Arizona and author of The Reason for Flowers. (Buchmann isn’t involved in the 1,000 Acre Initiative.)

Buchmann recommends against using herbicides or insecticides, or, if necessary, applying them at night when bees aren’t active. Providing nesting sites for certain bee species can help, too.

“People think they’ll just plant the wildflowers and the bees will come,” he says. “And that’s true in some cases, but the smaller the bee is, the less far it can fly. Some can only fly a few hundred meters.”

Some species nest in hard substrates, like the bare ground (bees hate mulch, says Buchmann), or in holes that you can drill in adobe or earthen bricks. Others nestle in sand pits or dead wood that’s been tunneled through by beetles. And it helps to have mud and water on the premises. The Xerces Society has a handy how-to guide on creating homes for bees.

The 1,000 Acre Pollinator Initiative is still looking into funding for the next four years, and they don’t expect to see huge jumps in the number of pollinators immediately. But Cedar Rapids is confident it will help, and they hope the project will serve as a model for the rest of the country.

And if enough local businesses and private landowners get involved, there’s no reason to stop at 1,000 acres, says Gibbins. “There’s a big push to extend this initiative up to maybe 10,000 acres in Linn County.”

http://www.popsci.com/Cedar-Rapids-Iowa-save-bee-pollinator#page-4

Through vegetables and fruits, the drugs that we flush down the drain are returning to us.

In a randomized, single-blind pilot study, researchers found that anticonvulsive epilepsy drug carbamazepine, which is released in urine, can accumulate in crops irrigated with recycled water—treated sewage—and end up in the urine of produce-eaters not on the drugs. The study, published Tuesday in Environmental Science & Technology, is the first to validate the long-held suspicion that pharmaceuticals may get trapped in infinite pee-to-food-to-pee loops, exposing consumers to drug doses with unknown health effects.

While the amounts of the drug in produce-eater’s pee were four orders of magnitude lower than what is seen in the pee of patients purposefully taking the drugs, researchers speculate that the trace amounts could still have health effects in some people, such as those with a genetic sensitivity to the drugs, pregnant women, children, and those who eat a lot of produce, such as vegetarians. And with the growing practice of reclaiming wastewater for crop irrigation—particularly in places that face water shortages such as California, Israel, and Spain—the produce contamination could become more common and more potent, the authors argue.

“The potential for unwitting exposure of consumers to contaminants via this route is real,” the authors wrote, adding that their study provides real world data that proves exposure occurs.

For the study, researchers recruited 34 healthy adults—excluding vegetarians, vegans, and people who take carbamazepine. The participants were all from Israel, where farmers use reclaimed water for 50 percent of the country’s irrigation needs. California, which grows a large portion of US produce, currently uses reclaimed water for six percent of its irrigation needs, but is looking to increase its usage.

First, the researchers measured what was in each participant’s pee, then randomly assigned them to one of two groups. While each participant got a big basket of produce to eat over one week and another basket for a second week, the contents varied depending on their group. Those in group one unknowingly started off with produce irrigated with reclaimed water and then got a batch irrigated with fresh water for the second week. Group two started with produce irrigated with fresh water, then were switched to crops bought at a local grocery store. (The authors admit that they meant to switch the second group to produce grown with reclaimed water for that second week, but they ran out.) The researchers weren’t sure what type of water was used to grow the grocery store produce, but they assumed it was a mix.

Throughout the two weeks, researchers sampled each participant’s urine, looking for carbamazepine and its metabolites—forms of the drug that have been modified in the human body.

At the start, the participants had mixed levels of carbamazepine in their urine, with ~38 percent having undetectable amounts, ~35 percent having detectable amounts that were too little to quantify, and ~26 having low but quantifiable amounts. After the first week, all of the participants in the first group, which noshed on produce irrigated with reclaimed water, had quantifiable amounts of the drug and its metabolites in their urine—some of the amounts hiked up by more than ten-fold from the start. Those in group two, however, didn’t change from their initial measurements.

In the second week, after the veggie swap, the levels of carbamazepine dropped back down to baseline levels in group one participants. Drug levels in participants in group two stayed about the same in the second week, despite some of the grocery store produce testing positive for carbamazepine.

Both of those findings—that drug levels can quickly drop after exposure and the mixed supermarket food didn’t alter levels—is relatively good news for public health, the authors note. Still, the unintentional drug doses in food are a concern worth more attention by the public health community, the authors conclude. Previous studies have found a variety of drugs in crops, including cholesterol medications, caffeine, and triclosan.

Environmental Science & Technology, 2015. DOI: 10.1021/acs.est.5b06256 (About DOIs).

Thanks to Kebmodee for bringing this to the It’s Interesting community.

By Eva Botkin-Kowacki

Plastic is everywhere around us. We drink out of plastic cups, buy disposable water bottles, unwrap new electronics from plastic packaging, take home plastic shopping bags, and even wear plastic in polyester fabrics.

Some 311 million tons of plastic is produced across the globe annually, and just 10 percent makes it back to a recycling plant. The rest ends up in landfills, or as litter on land or in the ocean, where it remains for decades and longer.

As for the plastic that has been recycled, it has given rise to an unintended side effect: A team of scientists searching through sediments at a plastic bottle recycling plant in Osaka, Japan have found a strain of bacteria that has evolved to consume the most common type of plastic.

Ideonella sakaiensis 201-F6 can degrade poly (ethylene terephthalate), commonly called PET or PETE, in as little as six weeks, they report in a new paper published Thursday in the journal Science.

Common uses of PET include polyester fibers, disposable bottles, and food containers. The last two are typically labelled with a No. 1 inside a recycling symbol.

But this new paper doesn’t mean you should ditch your reusable water bottles in favor of a tray of disposable ones, or that we’re going to inject this bacteria into landfills tomorrow. This study simply evaluated if the bacteria in question could degrade PET and was conducted under laboratory conditions.

“We hope this bacterium could be applied to solve the severe problems by the wasted PET materials in nature,” Kohei Oda, one of the study authors, tells The Christian Science Monitor in an email. But “this is just the initiation for application.” More research has to be done in order to make this a practical solution to plastic pollution.

But could this sort of fix work in theory?

“[Plastics] have been engineered for cost and for durability, or longevity,” says Giora Proskurowski, an oceanographer at the University of Washington who studies plastic debris in the ocean but was not part of this study, in a phone interview with the Monitor. But he’s hopeful that this research could yield further studies and technologies to mitigate the problem.

The durability of plastic isn’t the only challenge this potential fix faces. Microbes are like teenagers, Christopher Reddy, a senior scientist at Woods Hole Oceanographic Institution who studies environmental pollution and was not part of this study, explains in an interview with the Monitor.

“You can tell them to clean the garage over the weekend but they’re going to do it on their own timescale, they’re going to do it when they want, they’re going to pick the easiest thing to do and they’re likely going to leave you more frustrated than you think,” he explains the metaphor. Similarly, you can’t rely on microbes to break down compounds. “Don’t rely on microbes to clean the environment.”

Dr. Reddy says that has a lot to do with the environment outside the lab. In the experiment, he says, the researchers controlled the situation so the bacteria ate the plastic, but in nature, they would have many options for food.

Also, if I. sakaiensis 201-F6 were to be applied, it would likely only help plastic pollution on land. PET particles are denser than water, so they tend to sink down into the sediment. The trillions of tons of plastic particles amassing in the oceans are other types of plastics, types for which this bacteria probably lacks an appetite. Also, Dr. Proskurowski says, marine organisms have evolved to withstand the saltwater and sunlight that sediment-dwelling organisms might not.

Still, perhaps this bacteria could be harnessed to accelerate degradation of plastics that make it to a landfill, he says.

But this study does show that “the environment is evolving and you get the microbes evolving along with that as well,” Proskurowski says. “These are evolving systems.”

Neither Proskurowski nor Reddy were surprised that the researchers found an organism that can consume PET.

“I’m surprised it’s taken this long. I’ve been waiting for results like this,” Proskurowski says.

“Nature is incredibly wily, microbes are incredibly wily,” Reddy says. “Microbes are very good eaters.”

This is not the first time researchers have found an organism that will eat trashed plastic. Last year engineers at Stanford University found a mealworm that can eat styrofoam. And in that case, it was not the animal’s digestion that broke down the styrofoam, but bacteria it its gut.

http://www.csmonitor.com/Science/2016/0310/Researchers-discover-plastic-eating-bacteria-in-recycling-plant

There is no precedent in contemporary weather records for the kinds of droughts the country’s West will face, if greenhouse gas emissions stay on course, a NASA study said.

No precedent even in the past 1,000 years.

The feared droughts would cover most of the western half of the United States — the Central Plains and the Southwest.

Those regions have suffered severe drought in recent years. But it doesn’t compare in the slightest to the ‘megadroughts’ likely to hit them before the century is over due to global warming.
These will be epochal, worthy of a chapter in Earth’s natural history.

Even if emissions drop moderately, droughts in those regions will get much worse than they are now, NASA said.

The space agency’s study conjures visions of the sun scorching cracked earth that is baked dry of moisture for feet below the surface, across vast landscapes, for decades. Great lake reservoirs could dwindle to ponds, leaving cities to ration water to residents who haven’t fled east.

“Our projections for what we are seeing is that, with climate change, many of these types of droughts will likely last for 20, 30, even 40 years,” said NASA climate scientist Ben Cook.

That’s worse and longer than the historic Dust Bowl of the 1930s, when “black blizzards” — towering, blustery dust walls — buried Southern Plains homes, buggies and barns in dirt dunes.

It lasted about 10 years. Though long, it was within the framework of a contemporary natural drought.

To find something almost as extreme as what looms, one must go back to Medieval times.

Nestled in the shade of Southwestern mountain rock, earthen Ancestral Pueblo housing offers a foreshadowing. The tight, lively villages emptied out in the 13th century’s Great Drought that lasted more than 30 years.

No water. No crops. Starvation drove populations out to the east and south.

If NASA’s worst case scenario plays out, what’s to come could be worse.

Its computations are based on greenhouse gas emissions continuing on their current course. And they produce an 80% chance of at least one drought that could last for decades.

One “even exceeding the duration of the long term intense ‘megadroughts’ that characterized the really arid time period known as the Medieval Climate Anomaly,” Cook said.

That was a period of heightened global temperatures that lasted from about 1100 to 1300 — when those Ancestral Pueblos dispersed. Global average temperatures are already higher now than they were then, the study said.

The NASA team’s study was very data heavy.

It examined past wet and dry periods using tree rings going back 1,000 years and compared them with soil moisture from 17 climate models, NASA said in the study published in Science Advances.

Scientists used super computers to calculate the models forward along the lines of human induced global warming scenarios. The models all showed a much drier planet.

Some Southwestern areas that are currently drought-stricken are filling up with more people, creating more demand for water while reservoirs are already strained.

The predicted megadroughts will wrack water supplies much harder, NASA Goddard Space Flight Center said.

“These droughts really represent events that nobody in the history of the United States has ever had to deal with,” Cook said.

Compared with the last millennium, the dryness will be unprecedented. Adapting to it will be tough.

http://www.cnn.com/2015/02/14/us/nasa-study-western-megadrought/index.html