When Simon Leather was a student in the 1970s, he took a summer job as a postman and delivered mail to the villages of Kirk Hammerton and Green Hammerton in North Yorkshire. He recalls his early morning walks through its lanes, past the porches of houses on his round. At virtually every home, he saw the same picture: windows plastered with tiger moths that had been attracted by lights the previous night and were still clinging to the glass. “It was quite a sight,” says Leather, who is now a professor of entomology at Harper Adams University in Shropshire.
But it is not a vision that he has experienced in recent years. Those tiger moths have almost disappeared. “You hardly see any, although there used to be thousands in summer and that was just a couple of villages.”
It is an intriguing story and it is likely to be repeated over the next few weeks. The start of summer is the time of year when the nation’s insects should make their presence known by coating countryside windows with their fluttering presence, and splattering themselves on car windscreens. But they are spectacularly failing to do so. Instead they are making themselves newsworthy through their absence. Britain’s insects, it seems, are disappearing.
This point was underlined last week when tweets from the naturalist and TV presenter Chris Packham went viral after he commented on the absence of insects during a weekend at his home in the New Forest. Packham said he had not seen a single butterfly in his garden, and added that he sleeps with his windows open but rarely finds craneflies or moths in his room in the morning. By contrast, they were commonplace when he was a boy. “Our generation is presiding over an ecological apocalypse and we’ve somehow or other normalised it,” he later said. [Continue reading…]
Where have all Britain’s insects gone?
‘Shocking’ die-off of Africa’s oldest baobabs
Some of Africa’s oldest and biggest baobab trees — a few dating all the way back to the ancient Greeks — have abruptly died, wholly or in part, in the past decade, researchers said Monday.
The trees, aged between 1,100 and 2,500 years and some as wide as a bus is long, may have fallen victim to climate change, the team speculated.
“We report that nine of the 13 oldest… individuals have died, or at least their oldest parts/stems have collapsed and died, over the past 12 years,” they wrote in the scientific journal Nature Plants, describing “an event of an unprecedented magnitude.”
“It is definitely shocking and dramatic to experience during our lifetime the demise of so many trees with millennial ages,” said the study’s co-author Adrian Patrut of the Babes-Bolyai University in Romania.
Among the nine were four of the largest African baobabs.
While the cause of the die-off remains unclear, the researchers “suspect that the demise of monumental baobabs may be associated at least in part with significant modifications of climate conditions that affect southern Africa in particular.” [Continue reading…]
Humanity is a tiny fraction of life on Earth but has destroyed over 80% of wild mammals and half of plants
Humankind is revealed as simultaneously insignificant and utterly dominant in the grand scheme of life on Earth by a groundbreaking new assessment of all life on the planet.
The world’s 7.6 billion people represent just 0.01% of all living things, according to the study. Yet since the dawn of civilisation, humanity has caused the loss of 83% of all wild mammals and half of plants, while livestock kept by humans abounds.
The new work is the first comprehensive estimate of the weight of every class of living creature and overturns some long-held assumptions. Bacteria are indeed a major life form – 13% of everything – but plants overshadow everything, representing 82% of all living matter. All other creatures, from insects to fungi, to fish and animals, make up just 5% of the world’s biomass.
Another surprise is that the teeming life revealed in the oceans by the recent BBC television series Blue Planet II turns out to represent just 1% of all biomass. The vast majority of life is land-based and a large chunk – an eighth – is bacteria buried deep below the surface.
“I was shocked to find there wasn’t already a comprehensive, holistic estimate of all the different components of biomass,” said Prof Ron Milo, at the Weizmann Institute of Science in Israel, who led the work, published in the Proceedings of the National Academy of Sciences.
“I would hope this gives people a perspective on the very dominant role that humanity now plays on Earth,” he said, adding that he now chooses to eat less meat due to the huge environmental impact of livestock. [Continue reading…]
Someone, somewhere, is making a banned CFCs that destroys the ozone layer, scientists suspect
Emissions of a banned, ozone-depleting chemical are on the rise, a group of scientists reported Wednesday, suggesting someone may be secretly manufacturing the pollutant in violation of an international accord.
Emissions of CFC-11 have climbed 25 percent since 2012, despite the chemical being part of a group of ozone pollutants that were phased out under the 1987 Montreal Protocol.
“I’ve been making these measurements for more than 30 years, and this is the most surprising thing I’ve seen,” said Stephen Montzka, a scientist with the National Oceanic and Atmospheric Administration who led the work. “I was astounded by it, really.”
It’s a distressing result amid what is widely seen as a global environmental success story, in which nations — alarmed by a growing “ozone hole” — collectively took action to phase out chlorofluorocarbons.
The finding seems likely to prompt an international investigation into the mysterious source.
Officially, production of CFC-11 is supposed to be at or near zero — at least, that is what countries have been telling the U.N. body that monitors and enforces the Montreal Protocol. But with emissions on the rise, scientists suspect someone is making the chemical in defiance of the ban. [Continue reading…]
Glyphosate shown to disrupt microbiome ‘at safe levels’, study claims
A chemical found in the world’s most widely used weedkiller can have disrupting effects on sexual development, genes and beneficial gut bacteria at doses considered safe, according to a wide-ranging pilot study in rats.
Glyphosate is the core ingredient in Monsanto’s Roundup herbicide and levels found in the human bloodstream have spiked by more than a 1,000% in the last two decades.
The substance was recently relicensed for a shortened five-year lease by the EU. But scientists involved in the new glyphosate study say their results show that it poses “a significant public health concern”.
One of the report’s authors, Daniele Mandrioli, at the Ramazzini Institute in Bologna, Italy, said significant and potentially detrimental effects from glyphosate had been detected in the gut bacteria of rat pups born to mothers, who appeared to have been unaffected themselves.
“It shouldn’t be happening and it is quite remarkable that it is,” Mandrioli said. “Disruption of the microbiome has been associated with a number of negative health outcomes, such as obsesity, diabetes and immunological problems.”
Prof Philip J Landrigan, of New York’s Icahn School of Medicine, and also one of the research team, said: “These early warnings must be further investigated in a comprehensive long-term study.” He added that serious health effects from the chemical might manifest as long-term cancer risk: “That might affect a huge number of people, given the planet-wide use of the glyphosate-based herbicides.” [Continue reading…]
Rising incomes result in expanding forests
Forests are increasing around the world because of rising incomes and an improved sense of national wellbeing say researchers.
The authors refute the idea that increasing levels of CO2 in the atmosphere are the key cause of the spread of trees.
As countries become better off, farmers focus on good quality soils and abandon marginal lands, the authors say.
As a result, trees are able to rapidly reforest these deserted areas.
The study highlights the fact that between 1990 and 2015 forest growing stock increased annually by 1.31% in high income countries and by 0.5% in middle income nations, while falling by 0.72% in 22 low income countries.
Several global climate models have attributed this change to what’s termed CO2 fertilisation – where higher levels of carbon dioxide in the atmosphere boost the growing abilities of plants and trees.
But the authors say that this greening process has been going on since the 1800s in Western Europe when CO2 in the atmosphere was just starting to rise. [Continue reading…]
In the fate of the Delta smelt, warnings of conservation gone wrong
Peter Moyle, an eminent authority on the ecology and conservation of California’s fishes, stands on the narrow deck of a survey boat and gazes out over the sloughs of Suisun Marsh. The tall, tubular stems of tule reeds bend in the wind as a flock of pelicans soars past, their white wings edged in black. It’s an idyllic scene that hints at an earlier time, back before the Gold Rush, when undisturbed creeks and tidal marsh covered the Sacramento-San Joaquin Delta.
The Delta smelt has high odds of becoming the first fish to go extinct in the wild while under the protection of the federal Endangered Species Act.
In the delta, two of California’s greatest rivers meet and mingle with the ebb and flow of tides from San Francisco Bay, forming the largest estuary on the Pacific coast of the Americas. Moyle knows well how this place has changed. The delta’s once wild labyrinth of meandering rivulets and floating tule islands have been replaced by a network of levees that wall off agricultural fields, towns, and remnants of wildlife habitat from the tides. A legion of invasive species now course through the reshaped channels. The many tributaries that run down from the Sierras to feed the delta have been dammed and diverted to provide water for cities and farms — a maze of infrastructure and engineering that has pushed several species of native fish into steep decline.
The creature Moyle has studied the longest and knows most intimately is the Delta smelt, now on the brink of extinction.
Moyle was a young fishery ecologist, newly hired at the University of California, Davis, when he first encountered the finger-length, translucent fish in 1972. He chose to study the Delta smelt because it was abundant but little understood. During the 1980s, he documented a crash in the smelt population, and by 1993, the fish was listed as “threatened” under both the federal and California endangered species acts. As head of a team responsible for charting a course toward the smelt’s recovery, Moyle suggested a radical solution: Conservation in the delta, he said, should focus not just on the smelt, but on an array of native fish with different life histories and habitat needs, including steelhead and sturgeon. All of their populations were dwindling as humans reshaped the ecosystem, but only the smelt and winter-run Chinook salmon were officially listed as threatened.
Moyle’s idea didn’t take hold and government efforts instead followed the letter of the federal Endangered Species Act, focusing only on the smelt. Years of intense study and controversy followed, including a series of court cases over allocating water for smelt habitat. The species continued to dwindle. In 2009, California officials changed the smelt’s status in their listing from threatened to endangered, and by then, another run of Chinook salmon, a run of steelhead, and the region’s population of green sturgeon had all joined the smelt on the federal endangered species list.
In the spring of 2015, a survey of wild spawning smelt found only six fish. Today, an estimated 48,000 survive in the wild — a small remnant of pre-crash populations. About the same number live in culture facilities created to prevent the smelt’s extinction. To some Californians, that’s of little consequence, and they regard efforts to protect remaining smelt as an exemplar of absurd environmental overreach. Why should an obscure fish, rarely seen by anyone but researchers, impair the flow of precious delta water to the thirsty farms and cities of Southern California?
But many ecologists, Moyle among them, consider the smelt’s rapid disappearance the signature of both an ecosystem, and a conservation strategy, in crisis. [Continue reading…]
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China-backed Sumatran dam threatens the rarest ape in the world
By Bill Laurance, James Cook University
The plan to build a massive hydropower dam in Sumatra as part of China’s immense Belt and Road Initiative threatens the habitat of the rarest ape in the world, which has only 800 remaining members.
This is merely the beginning of an avalanche of environmental crises and broader social and economic risks that will be provoked by the BRI scheme.
Read more:
How we discovered a new species of orangutan in northern Sumatra
The orangutan’s story began in November 2017, when scientists made a stunning announcement: they had discovered a seventh species of Great Ape, called the Tapanuli Orangutan, in a remote corner of Sumatra, Indonesia.
In an article published in Current Biology today, my colleagues and I show that this ape is perilously close to extinction – and that a Chinese-sponsored megaproject could be the final nail in its coffin.
Sumatran Orangutan Society
Alaskan sea ice just took a steep, unprecedented dive
April should be prime walrus hunting season for the native villages that dot Alaska’s remote western coast. In years past the winter sea ice where the animals rest would still be abundant, providing prime targets for subsistence hunters. But this year sea-ice coverage as of late April was more like what would be expected for mid-June, well into the melt season. These conditions are the continuation of a winter-long scarcity of sea ice in the Bering Sea—a decline so stark it has stunned researchers who have spent years watching Arctic sea ice dwindle due to climate change.
Winter sea ice cover in the Bering Sea did not just hit a record low in 2018; it was half that of the previous lowest winter on record (2001), says John Walsh, chief scientist of the International Arctic Research Center at the University of Alaska Fairbanks. “There’s never ever been anything remotely like this for sea ice” in the Bering Sea going back more than 160 years, says Rick Thoman, an Alaska-based climatologist with the National Oceanic and Atmospheric Administration.
A confluence of conditions—including warm air and ocean temperatures, along with persistent storms—set the stage for this dramatic downturn in a region that to date has not been one of the main contributors to the overall reduction of Arctic sea ice. Whereas a degree of random weather variability teed up this remarkable winter, the background warming of the Arctic is what provides the “extra kick” to reach such unheard-of extremes, Walsh says. [Continue reading…]
How a Eurasian steppe empire coped with decades of drought
By Diana Crow
The bitterly cold, dry air of the Central Asian steppe is a boon to researchers who study the region. The frigid climate “freeze-dries” everything, including centuries-old trees that once grew on lava flows in Mongolia’s Orkhon Valley. A recent study of the tree-ring record, published in March, from some of these archaic logs reveals a drought that lasted nearly seven decades—one of the longest in a 1,700-year span of steppe history—from A.D. 783–850.
Decades of prolonged drought would have killed much of the grass that the Orkhon Valley’s domesticated horses relied upon. Yet the dominant steppe civilization of the era, an empire of Turkic horse nomads called the Uyghurs, somehow survived nearly 60 years of the drought, a period about seven times longer than the Dust Bowl that devastated the central U.S. in the 1930s.
Based on surviving Chinese and Uyghur documents from the drought years, the study’s authors concluded that the Uyghurs survived by diversifying their economy and using international diplomacy to boost trade.
Rather than driving the Uyghurs to plunder neighboring territories—as other steppe empires tended to do—the drought led them to take advantage of their location on the Silk Road and reinvent their economy. The Uyghurs’ relatively peaceful strategies seem to have staved off total collapse for a surprisingly long time. “They were champs,” says physical geographer and study co-author Amy Hessl of West Virginia University.
Prior to this paper, no one knew that the Uyghurs faced an “epic drought,” Hessl says. The recognition that they did may change the way historians interpret the social, political, and economic strategies of the Uyghurs.