Friday, June 30, 2017

Mapping The Potential Economic Effects Of Climate Change

[NPR] Climate scientists agree that this century is getting much warmer and that such warming will likely bring economic pain to the U.S., but economists aren't sure how much. Now, a team of scientists and economists, writing in the upcoming issue of the journal Science, says it can at least tell which parts of the country are likely to suffer the most.
The researchers started with history: How have heat waves and drought affected the economy in the past? Then they applied that metric to a range of future warming scenarios — from minor to extreme — and mapped the effects, county by county across the U.S. They found that if warming continues at recent rates, it could shave 3 to 6 percentage points off of the country's gross domestic product by century's end — the warmer it gets, the bigger the hit to the economy.
Lead researcher Solomon Hsiang acknowledges that the numbers are uncertain by scientific standards but that they aren't really the bottom line. "I think the takeaway message that is most striking is that the effects of climate change on the U.S. are not the same everywhere," says Hsiang, an economist at the University of California, Berkeley. "Where you are in the country really matters."
Colder places like New England might see an economic upturn — for example, from lower heating bills. But places that are already hot, like the South and Midwest, could see huge damage to their local economies, due to enormous electric bills, dying crops or mass migration away from the area.
Maybe that is not so surprising, but Hsiang takes it a step further: Climate change will redistribute wealth by driving workers, businesses and agriculture away from those hard-hit regions and move them mostly toward the north and west of the country. Again, Hsiang says exactly how much is hard to predict. But he says that is actually part of the new study's findings: "When you start changing the climate," he says, "it starts affecting all these aspects of the economy, and it makes the future world harder to predict." Read More

Thursday, June 29, 2017

Psychics Who Hear Voices Could Be On to Something

[The Atlantic] Jessica Dorner was lying in bed at her cousin’s house when her grandmother, a “pushy lady” in an apron who had been dead for several years, appeared in front of her. “I know you can see me,” Jessica heard her say, “and you need to do something about it.”
It was a lonely time in Jessica’s life. She was living away from home for the first time, and she thinks her grandmother was drawn by some sense of that. She eventually told her parents what happened, and according to her they were concerned, but not overly panicked. “My parents are probably the least judgmental people I know,” she said.
As Jessica tells it, over the next two years, spirits visited her every now and again. Her brother-in-law’s deceased father began forming before her, ghostlike, just as her grandmother did. And while the experiences were intense and at times made her feel “crazy,” she said, they were infrequent, and insists that they were never a real source of suffering.
Jessica later moved back home and got a job as a pharmacy technician, all the while figuring out how to cope with what was happening to her. At a co-worker’s suggestion, she went to the Healing in Harmony center in Connecticut. In 2013, she says, she enrolled in classes there that taught her to use her “gift.” A self-described psychic medium, Jessica tells me she hears voices that other people do not (in addition to sometimes seeing people others do not see), at varying intensity, and mostly through her right ear.
Meeting others like her at the center gave Jessica a sense of relief. “Just being around people who are going through similar things—that helps a lot, because I could talk to anybody about those things and not feel like I was crazy,” she said.
It was through a friend from the center that Jessica ended up in the lab of Philip Corlett and Albert Powers, a psychologist and a psychiatrist at Yale. In a study published last fall in Schizophrenia Bulletin, Powers and Corlett compared self-described psychics with people diagnosed with a psychotic disorder who experience auditory hallucinations.
“A lot of the time, if someone says they hear voices, you immediately jump to psychotic illness, bipolar disorder, schizophrenia,” Corlett said. But research suggests hearing voices is not all that uncommon. A survey from 1991—the largest of its kind since—found that 10 to 15 percent of people in the U.S. experienced sensory hallucinations of some sort within their lifetime. And other research, as well as growing advocacy movements, suggest hearing voices isn’t always a sign of psychological distress.
The researchers at Yale were looking for a group of people who hear voices at least once a day, and had never before interacted with the mental-health-care system. They wanted to understand, as Corlett put it, those who do not suffer when “the mind deviates from consensual reality.” Read More

Monday, June 26, 2017

Ram Dass – Here and Now – Ep. 112 – The Notion of Ego with Chogyam Trung...

Many Native Communities Are Being Forced to Relocate Due to Climate Change

[The Planet] Fawn Sharp grew up in Taholah village, a small community on the Quinault Reservation nestled between the mouth of the Quinault River and the Pacific Ocean. She spent her childhood summers surrounded by water, splashing in Lake Quinault on the eastern edge of the reservation, and hiking along the local beaches near the village, scouring the rocks for starfish and other treasures. In the mornings, she was often up before the sun, out fishing with her grandparents on the river.
Decades after she left home for college, Sharp is back on the reservation, this time living near the lake, some 35 miles from her childhood home in Taholah. Now she goes by President Sharp, and leads both the Quinault Indian Nation and the Affiliated Tribes of Northwest Indians.
Since returning, Sharp has faced the kinds of tough issues that might have seemed outlandish, or even inconceivable, during her childhood. She’s seen the tribe’s salmon runs in sharp decline. She’s observed the rapid retreat of nearby glaciers. And she’s watched her childhood home, Taholah, endure dangerous flooding during increasingly harsh storm surges.
Given the growing threat that climate change poses to the “lower village,” as tribal members refer to the lower portion of Taholah, paired with ongoing concerns about the village’s vulnerability to earthquakes and tsunamis, Sharp and the Quinault leadership were forced to make an almost unthinkable decision: to leave home.
The Quinault have lived on the Olympic Peninsula for centuries, since long before the 1855 Quinault River Treaty established the Quinault Reservation and ceded vast tracts of lands to Washington State. The reservation is wedged between the towering mountains and dense temperate rainforest of Olympic National Park to the east and beaches and oceans to the west. It’s bisected by the swift Quinault River, and is home to black bear, Roosevelt elk, and bald eagles. The tribe’s ties to the land are strong. As it proudly claims on its website: “We are among the small number of Americans who can walk the same beaches, paddle the same waters, and hunt the same lands our ancestors did centuries ago.” Read More

Wednesday, June 21, 2017

Stephen Hawking calls for a return to the moon as Earth’s clock runs out

[Washington Post] Humans are overdue for a return trip to the moon, Stephen Hawking has just opined.
Speaking on Tuesday at the Starmus Festival, a science-slash-musical gathering, the astrophysicist offered two parts doom cut with one part scientific optimism. He argued that we should prepare for a cosmic exodus to take place in the next 200 to 500 years.
“We are running out of space, and the only place we can go to are other worlds. It is time to explore other solar systems,” he said via video link to the audience gathered in Trondheim, Norway. “Spreading out may be the only thing that saves us from ourselves. I am convinced that humans need to leave Earth.”
Hawking's plan to boogie off this planet is ambitious: Countries should collaborate to construct a moon colony within 30 years. We can reach Mars “in the next 15 years,” he said, with a base to follow a few decades later.
The head of the European Space Agency said in 2016 that a “moon village” would take 20 years to plan and construct. NASA's long-term plans include sending humans to Mars by the 2030s.
Astronauts last walked on the moon in 1972, the same year that Elton John's “Rocket Man” debuted on vinyl. The final lunar visitor, Eugene Cernan, died in January. Cernan remained a lifelong advocate for space travel, testifying before Congress in 2011 that American space exploration was on “a path of decay” after the Obama administration shuttered NASA's Constellation moon program.
Hawking's gloom goes beyond decay into eschatology. In November, he said we had about 1,000 years left before escaping to the stars. In May, he chopped that timetable to the next hundred years. During his speech Tuesday, titled “The future of humanity,” the 75-year-old black hole expert said that “Earth is under threat from so many areas that it is difficult for me to be positive.” Read More

The failures of modern capitalism are forcing us to appreciate the virtues of the simple life again

[Quartz] The good life is the simple life. Among philosophical ideas about how we should live, this one is a hardy perennial; from Socrates to Thoreau, from the Buddha to Wendell Berry, thinkers have been peddling it for more than two millennia. And it still has plenty of adherents. Magazines such as Real Simple call out to us from the supermarket checkout; Oprah Winfrey regularly interviews fans of simple living such as Jack Kornfield, a teacher of Buddhist mindfulness; the Slow Movement, which advocates a return to pre-industrial basics, attracts followers across continents.
Through much of human history, frugal simplicity was not a choice but a necessity—and since necessary, it was also deemed a moral virtue. But with the advent of industrial capitalism and a consumer society, a system arose that was committed to relentless growth, and with it grew a population (aka “the market”) that was enabled and encouraged to buy lots of stuff that, by traditional standards, was surplus to requirements. As a result, there’s a disconnect between the traditional values we have inherited and the consumerist imperatives instilled in us by contemporary culture.
In pre-modern times, the discrepancy between what the philosophers advised and how people lived was not so great. Wealth provided security, but even for the rich wealth was flimsy protection against misfortunes such as war, famine, disease, injustice and the disfavor of tyrants. The Stoic philosopher Seneca, one of the richest men in Rome, still ended up being sentenced to death by Nero. As for the vast majority—slaves, serfs, peasants and laborers—there was virtually no prospect of accumulating even modest wealth.
Before the advent of machine-based agriculture, representative democracy, civil rights, antibiotics and aspirin, just making it through a long life without too much suffering counted as doing pretty well. Today, though, at least in prosperous societies, people want and expect (and can usually have) a good deal more. Living simply now strikes many people as simply boring. Read More

North Korea and U.S. War the Subject of Peruvian Shamans' Prevention Ritual

[Newsweek] Increasing military tensions between North Korea and the U.S. aren’t just causing concern for East Asia—in Peru, four shamans have performed a ritual in a bid to save the world from a third world war.
The shamans carried their instruments, skulls, flowers, candles, American and North Korean flags to a hill just outside the capital of Lima on Monday and built an altar pointing to the four cardinal points.
As part of the ritual, they placed hot spices, incense, fruit, herbs and stones on posters of U.S. President Donald Trump, North Korean leader Kim Jong Un and Russian President Vladimir Putin. They then made a plea for peace and “to avoid any unnecessary deaths,” shaman Juán Osco explained, quoted in Spanish news agency Efe.
“We are doing a special ritual for peace between the U.S. and North Korea because they are using all the best modern weapons, but the world demands peace and not conflicts, wars, destructions and slaughter,” Osco told Euronews.
The shamans, who are considered to be physical and spiritual healers, closely follow world events in their rituals. Some of the shamans who performed the ritual on Monday were also involved in one just ahead of the U.S. presidential election in November. At the time, EFE reported, their predictions on the winners differed: Osco forecast a victory for Democrat candidate Hillary Clinton, while shaman Marino de los Santos said Trump would win because of his “spiritual powers.” Read More

By 2100, Deadly Heat May Threaten Majority of Humankind

[National Geographic] A new study has found that 30 percent of the world’s population is currently exposed to potentially deadly heat for 20 days per year or more—and like a growing forest fire, climate change is spreading this extreme heat.
Without major reductions in emissions of greenhouse gases such as CO2, up to three in four people will face the threat of dying from heat by 2100. However, even with reductions, one in two people at the end of the century will likely face at least 20 days when extreme heat can kill, according to the analysis, published on Monday in Nature Climate Change.

“Lethal heatwaves are very common. I don’t know why we as a society are not more concerned about the dangers,” says Camilo Mora of the University of Hawaii at Manoa, the study’s lead author. “The 2003 European heatwave killed approximately 70,000 people—that’s more than 20 times the number of people who died in the September 11 attacks.”
Dangerous heatwaves are far more common than anyone realized, killing people in more than 60 different parts of the world every year. Notable deadly heatwaves include the 2010 Moscow event that killed at least 10,000 people and the 1995 Chicago heatwave, where 700 people died of heat-related causes. Read More

Sunday, June 18, 2017

A Texas-size chunk of Antarctica partially melted last year

[Popular Science] El Niño has given us a preview of West Antarctica’s future, and things do not look good.
For two weeks in January of 2016, unusually warm weather caused a 300,000 square mile patch of the Ross Ice Shelf to partially melt. The roughly Texas-sized area, blanketed in a slushy mixture of ice and water, represents one of the first times scientists have been able to catch such widespread Antarctic melting in action. The findings were published this week in Nature Communications.
The meltwater caused no sea level rise, because eventually it re-froze. So this event poses no immediate danger to us. But it does give scientists a terrifying glimpse into Antarctica’s future.
A strong El Niño event caused the bizarrely warm conditions. During the El Niño climate pattern, the Pacific Ocean’s surface heats up around the equator, and currents carry the warmer than average temperatures to Canada, the U.S., and Antarctica. In this case, El Niño brought rainfall to West Antarctica, which is quite an extraordinary event.
“The story of melt all over the ice shelf rattled through the science community as it happened,” Robin Bell, an Antarctic researcher at Columbia University who was not involved in the study told The Washington Post. “Who had heard of rain in Antarctica—it is a desert!”
As our planet warms, El Niño events are expected to become more frequent over the next century. So melting events like this could become more common, too.
We already knew that warm ocean waters have been melting the Ross Ice Shelf—the world’s largest block of floating ice—from below. The new research confirms that balmy weather can melt it from above as well.
Being attacked from the bottom and the top could make Ross fracture and collapse more quickly. That’s not good, because ice shelves like Ross help hold Antarctic ice on land, which keeps glaciers out of the water. Once the shelves fracture, that ice can pour into the ocean a lot faster. David Bromwich, a climate researcher at Ohio State University, told Motherboard that if the Ross Ice Shelf collapses, sea levels would rise by 11 feet, which could flood nearly 30,000 square miles in the U.S. alone. Read More

Friday, June 16, 2017

Earth Is Not in the Midst of a Sixth Mass Extinction

[The Atlantic] At the annual meeting of the Geological Society of America, Smithsonian paleontologist Doug Erwin took the podium to address a ballroom full of geologists on the dynamics of mass extinctions and power grid failures—which, he claimed, unfold in the same way.
“These are images from the NOAA website of the US blackout in 2003,” he said, pulling up a nighttime satellite picture of the glowing northeastern megalopolis, megawatts afire under the cold dark of space. “This is 20 hours before the blackout. You can see Long Island and New York City.”
“And this is seven hours into the blackout,” he said, pulling up a new map, cloaked in darkness. “New York City is almost dark. The blackout extended all the way up into Toronto, all the way out to Michigan and Ohio. It covered a huge section of both Canada and the United States. And it was largely due to a software bug in a control room in Ohio.”
Erwin is one of the world’s experts on the End-Permian mass extinction, an unthinkable volcanic nightmare that nearly ended life on earth 252 million years ago. He proposed that earth’s great mass extinctions might unfold like these power grid failures: most of the losses may come, not from the initial shock—software glitches in the case of power grid failures, and asteroids and volcanoes in the case of ancient mass extinctions—but from the secondary cascade of failures that follow. These are devastating chain reactions that no one understands. Erwin thinks that most mass extinctions in earth’s history—global die-offs that killed the majority of animal life on earth—ultimately resulted, not from external shocks, but from the internal dynamics of food webs that faltered and failed catastrophically in unexpected ways, just as the darkening eastern seaboard did in 2003.
“Because it was not clear how to manage that collapse—although after the fact it was clear that it should have been easily contained—it cascaded into failure of grids across the northeastern United States ...  I mention this because it turns out that, from a mathematical point of view, the problem of understanding these food webs is exactly the [same] problem as understanding the nature of the power grid. There’s a very rapid collapse of the ecosystem during these mass extinctions,” he said. Read More

Climate Change Pushing Tropical Diseases Toward Arctic

[National Geographic] He'd gone for a swim in the Gulf of Mexico, whose warm waters, it turned out, would soon kill him. The 31-year-old man arrived at Parkland Memorial Hospital in Dallas three days after his dip in the Atlantic. Crushing pain was radiating from his new calf tattoo—an image of hands clasping a cross along with the phrase "Jesus is my life." He had a fever, and dangerously low blood pressure. Black blisters appeared around his ankles. His kidneys and lungs began shutting down. Gangrenous tissue splotched his hips and toes. Within two months, he was dead.
The culprit, a meddlesome bacterium called Vibrio vulnificus, occurs naturally in warm ocean water. It can seep into scrapes or fresh wounds, including those from tattoo needlework. Infections like the one that killed this man in 2016 have appeared sporadically for years in warm seas from Texas to Maryland. But as greenhouse gases boost temperatures across the globe, rare pathogens like these from hotter parts of the planet are now creeping toward the poles, creating new risks for people. Deadly warm-water Vibrio illnesses are on the rise, now appearing even near the Arctic Circle.
"We are seeing lots of new hospitable areas opening up for these bacteria," says Craig Baker-Austin, a Vibrio expert who runs the United Kingdom's Centre for Environment, Fisheries and Aquaculture Sciences laboratory in southern England. "Climate change is essentially driving this process, especially warming."
t's no secret that climate change can spread illnesses such as West Nile virus, Zika, and malaria, as rising temperatures push disease-carrying mosquitoes into new places, from the highlands of Ethiopia to the United States. But warm temperatures and shifting weather patterns work in subtle ways, too. Changes in precipitation, wind, or heat are shifting the threat posed by other human illnesses, from cholera to a rare freshwater brain-eating amoeba to rodent-driven infections like hantavirus. And the importance of all these changes are only growing more significant. Read More

Rain and snow help stress out earthquake faults A little bit.

[Popular Science] Natural forces shape every inch of our globe, but in California, the two big players are water falling out of the sky (or the lack thereof) and earthquakes.
For a long time, many researchers figured that the two were unrelated. Earthquakes can mess with groundwater levels and aquifers, but not rain, and for the most part, it was assumed that rain and snow didn’t make enough of an impression on the Earth to really affect earthquakes either.
But a study published today in Science found a connection between seasonal precipitation and earthquakes, especially some of the very small ones.
Much of California has two distinct seasons—wet and dry. During the wet season, reservoirs fill, snowpacks build up on mountaintops, and the ground fills with moisture. In drier months, all that water starts moving, melting, and evaporating. This massive amount of water concentrated in the region collectively weighs so much that it can push down on the Earth by a fraction of an inch.
Earth scientists Christopher Johnson and Roland Bürgmann of UC Berkeley were able to measure those seasonal flexes in the Earth using a network of sensors called EarthScope that tracks tiny movements of the ground under our feet. The network includes GPS measurements (like you have in your phone) that record how the Earth’s surface moves in response to stress. For instance, a bunch of water being dumped on it every season. Read More

Thursday, June 8, 2017

How Spirituality Helped Me Overcome Crippling Depression

[MindBodyGreen] My youth was filled with ups and downs. I lost my mom when I was a baby and my life was forever changed. This great disruption imprinted a deep loss in my heart and soul that, still to this day, I do not fully understand how to soothe. My family life growing up was highly dysfunctional, toxic, and abusive. For many years, I struggled to find my place in the world, had a hard time accepting who I was, and struggled with severe anxiety and depression.
I am an empathic, sensitive soul, and I often take on what others are feeling. Early on, I learned that I needed to put practices in place to keep me grounded and in touch with my own energy. Finding yoga and nutrition at 20 radically shifted my physical connection to myself, helping me nourish my body and mind with clean foods and restorative poses. But it also taught the importance of my relationship to spirit: to myself, the earth, and all of life.
This connection began to take precedence over fleeting happiness drawn in from material things and consumerism. I like a well-made product as much as the next gal, but the deep fulfillment that comes from matters of the heart is so much more important to me. The raw beauty of human connection and the love we share with our friends and family is spirit in its purest form. When I focus my attention on the connection to spirit, my whole life lights up.
The heart is the essence of spirituality. It’s where the soul meets body and we become aware of our inherent life force. It's where we feel deeply, open ourselves to love, and find tenderness when things become challenging. Connecting my mind and body by way of the heart was such a profound step for me. This integration of head and heart allowed me to listen to my intuition, tune into my body’s changing needs, feel more, and think less. Read More

Seismic CT scan points to rapid uplift of Southern Tibet

[Scienmag] Using seismic data and supercomputers, Rice University geophysicists have conducted a massive seismic CT scan of the upper mantle beneath the Tibetan Plateau and concluded that the southern half of the “Roof of the World” formed in less than one-quarter of the time since the beginning of India-Eurasia continental collision.
The research, which appears online this week in the journal Nature Communications, finds that the high-elevation of Southern Tibet was largely achieved within 10 million years. Continental India’s tectonic collision with Asia began about 45 million years ago.
“The features that we see in our tomographic image are very different from what has been seen before using traditional seismic inversion techniques,” said Min Chen, the Rice research scientist who headed the project. “Because we used full waveform inversion to assimilate a large seismic data set, we were able to see more clearly how the upper-mantle lithosphere beneath Southern Tibet differs from that of the surrounding region. Our seismic image suggests that the Tibetan lithosphere thickened and formed a denser root that broke away and sank deeper into the mantle. We conclude that most of the uplift across Southern Tibet likely occurred when this lithospheric root broke away.”
The research could help answer longstanding questions about Tibet’s formation. Known as the “Roof of the World,” the Tibetan Plateau stands more than three miles above sea level. The basic story behind its creation — the tectonic collision between the Indian and Eurasian continents — is well-known to schoolchildren the world over, but the specific details have remained elusive. For example, what causes the plateau to rise and how does its high elevation impact Earth’s climate?
“The leading theory holds that the plateau rose continuously once the India-Eurasia continental collision began, and that the plateau is maintained by the northward motion of the Indian plate, which forces the plateau to shorten horizontally and move upward simultaneously,” said study co-author Fenglin Niu, a professor of Earth science at Rice. “Our findings support a different scenario, a more rapid and pulsed uplift of Southern Tibet.” Read More

My month with chemtrails conspiracy theorists

[The Guardian] Standing between beds of golden beets and elephant garlic in the garden of Lincoln Hills, a small organic farm in Placer County, California, Tammi Riedl looks up and points to a stripe of white haze running across a cloudless blue sky.
“See that?” she asks, raising her eyebrows. “What do you think that is?”
I look up. The white stripe looks like a normal contrail of jet engine exhaust to me. But to Tammi, a 54 year-old organic farmer, it’s a “chemtrail”: a toxic cocktail of aluminum, strontium and barium sprayed from planes in a plot to control the weather, the population and our food supply.
“See how it dissipates and becomes cloud cover?” she says. “That’s not normal.”
I nod, unsure how to respond to this unexpected declaration, and Tammi resumes demonstrating how to cover crop rows with frost blankets.
For the month of January, in an attempt to escape seasonal and post-election depression, I applied to work as a part-time farmhand at Lincoln Hills in exchange for room and board after spotting the arrangement advertised on the website HelpX.
To someone accustomed to New York City’s mouse-infested apartments, the farm was cartoonishly idyllic: on 10 acres in the Sierra Nevada foothills, sheep graze on blackberry bushes, a baby mule frolics, and free-range chickens pluck worms from compost heaps. But for the residents who subscribe to the chemtrails conspiracy theory, what looks like a perfect bucolic scene feels shrouded in danger.
Tammi and her boyfriend, Rob Neuhauser, are among the estimated 5% of Americans who believe that various global powers, including the US government, run clandestine and harmful chemical-spraying programs.
Versions of the chemtrails (or “covert geoengineering”) theory abound, and Tammi’s goes roughly like this: to mitigate global warming, mysterious airplanes spray chemicals into the atmosphere to form sun-blocking artificial cloud cover. This is done in secret, because these chemicals wreak havoc on environmental and human health, causing “Alzheimer’s, all sorts of brain problems, cancer”, she says.
Despite her adherence to USDA organic guidelines, Tammi fears that the chemical spraying means the produce she sells and donates to the Placer Food Bank isn’t technically organic. “It makes me think, ‘Wow, are we going to have to start growing everything indoors, under tunnels?’” she says. “Because the air is not healthy for crops.” Read More

More than 360 species of large mammal now at highest level of threat as humans pose ever-bigger extinction risk, experts warn

[Daily Mail] An ever-expanding human population and exploding demand for food, water and living space, will place animals at 'unprecedented' extinction risk in the next 50 years, experts warned Wednesday.
Facing the highest level of threat are more than 360 species of large mammals in Africa, Asia and South America -- the most biodiverse regions of the world, said a review published in the journal Nature Insight.
But all is not lost, and a drastic change to human diets and farming methods could provide 'healthy diets' for 10 billion people by 2060, while also preserving liveable habitats for most remaining species, it concluded.
'With forethought and timely action, these goals can be achieved.'
Successive waves of species extinctions have followed in the wake of modern humans' spread out of Africa to the rest of the world.
By 3,000 years ago, Earth had lost half of its terrestrial mammal mega-species -- animals which weigh more than 44 kilogrammes (97 pounds) -- and 15 percent of its birds.
The human population at seven billion is now 25 times larger than it was then, and projected to add another four billion mouths to feed by century's end.
Already, a quarter of mammal species and 13 percent of birds are threatened with extinction, said the review authors.
'Extinction rates for birds, mammals and amphibians are similar at present to those of the five global mass-extinction events of the past 500 million years that probably resulted from meteorite impacts, massive volcanism and other cataclysmic forces,' they wrote.
One such event is thought to have wiped out the dinosaurs.
Hunting, culling and poaching imperils up to half of threatened bird and mammal species, said the paper.
Designated protected areas now cover about 14 percent of Earth's land surface, yet biodiversity continues to decline worldwide. Read More