DATE: March 18, 2022
SOURCE: Washington Post
SNIP: The coldest location on the planet has experienced an episode of warm weather this week unlike any ever observed, with temperatures over the eastern Antarctic ice sheet soaring 50 to 90 degrees above normal. The warmth has smashed records and shocked scientists.
“This event is completely unprecedented and upended our expectations about the Antarctic climate system,” said Jonathan Wille, a researcher studying polar meteorology at Université Grenoble Alpes in France, in an email.
“Antarctic climatology has been rewritten,” tweeted Stefano Di Battista, a researcher who has published studies on Antarctic temperatures. He added that such temperature anomalies would have been considered “impossible” and “unthinkable” before they actually occurred.
Parts of eastern Antarctica have seen temperatures hover 70 degrees (40 Celsius) above normal for three days and counting, Wille said. He likened the event to the June heat wave in the Pacific Northwest, which scientists concluded would have been “virtually impossible” without human-caused climate change.
What is considered “warm” over the frozen, barren confines of eastern Antarctica is, of course, relative. Instead of temperatures being minus-50 or minus-60 degrees (minus-45 or minus-51 Celsius), they’ve been closer to zero or 10 degrees (minus-18 Celsius or minus-12 Celsius) — but that’s a massive heat wave by Antarctic standards.
The average high temperature in Vostok — at the center of the eastern ice sheet — is around minus-63 (minus-53 Celsius) in March. But on Friday, the temperature leaped to zero (minus-17.7 Celsius), the warmest it’s been there during March since record keeping began 65 years ago. It broke the previous monthly record by a staggering 27 degrees (15 Celsius).
“In about 65 record years in Vostok, between March and October, values above -30°C were never observed,” wrote Di Battista in an email.
Vostok, a Russian meteorological observatory, is about 808 miles from the South Pole and sits 11,444 feet above sea level. It’s famous for holding the lowest temperature ever observed on Earth: minus-128.6 degrees (minus-89.2 Celsius), set on July 21, 1983.
Temperatures running at least 50 degrees (32 Celsius) above normal have expanded over vast portions of eastern Antarctica from the Adélie Coast through much of the eastern ice sheet’s interior. Some computer model simulations and observations suggest temperatures may have even climbed up to 90 degrees (50 Celsius) above normal in a few areas.
Eastern Antarctica’s Concordia research station, operated by France and Italy and about 350 miles from Vostok, climbed to 10 degrees (minus-12.2 Celsius), its highest temperature on record for any month of the year. Average high temperatures in March are around minus-56 (minus-48.7 Celsius).
At a nearby weather station, the temperature reached 13.6 degrees (minus-10.2 Celsius) about 67 degrees (37 Celsius) above average, according to University of Wisconsin Antarctic researchers Linda Keller and Matt Lazzara.
Keller and Lazzara said in an email that such a high temperature is particularly noteworthy since March marks the beginning of autumn in Antarctica, rather than January, when there is more sunlight. At this time of year, Antarctica is losing about 25 minutes of sunlight each day.
Wille said the warm conditions over Antarctica were spurred by an extreme atmospheric river, or a narrow corridor of water vapor in the sky, on its east coast. According to computer models, the atmospheric river made landfall on Tuesday between the Dumont d’Urville and Casey Stations and dropped an intense amount of rainfall, potentially causing a significant melt event in the area.
The moisture from the storm diffused and spread over the interior of the continent. However, a strong blocking high pressure system or “heat dome,” moved in over east Antarctica, preventing the moisture from escaping. The heat dome was exceptionally intense, five standard deviations above normal.
The excessive moisture from the atmospheric river was able to retain large amounts of heat, while the liquid-rich clouds radiated the heat down to the surface — known as downward long-wave radiation.
Wille explained warm air is often transported over the Antarctic interior this way but not to this extent or intensity. “[T]his is not something we’ve seen before,” he said. “This moisture is the reason why the temperatures have gotten just so high.”
Models show the atmospheric river will exit the continent around Saturday, but the moisture will take longer to dissipate. Abnormally high temperatures in the region could last through the weekend.
The abnormally high temperatures have caused some melting in the region according to models, which is unusual as this part of Antarctica doesn’t experience much melt often. This one melt event won’t affect the stability of the glaciers in that area though.
“This event happened in a location that doesn’t often have melt. Obviously, this doesn’t mean that from now on we’re worried that melting will happen,” Wille said. “It’s more of like, ‘Oh, that is weird, that could happen more in the future and then this could be bad.’”
Wille said it’s difficult to attribute this one event to climate change at the moment, but he does think rising temperatures helped prime conditions for such an event. Climate change is “loading the dice” for more situations like this, he said.
Wille and his colleagues are studying how climate change will affect the circulation patterns around Antarctica and whether atmospheric rivers will become more common or more intense.
“We do believe they will become more intense because it just simple physics … but the details, we’re still trying to figure that out. It would be very difficult to say that there’s not a climate change fingerprint on an event like this,” he said.
Keller and Lazzara suggested more study is needed on the climate change connection.
“[W]e can’t tell whether this is going to be a new trend or is just an oddity that occurs occasionally on a most fascinating continent,” they wrote.
Temperatures are known to vary wildly over Antarctica, and massive swings are common. Contrasting with this warm spell over eastern Antarctica, the South Pole observed just observed its coldest April to September period on record last year, with an average temperature of minus-78 degrees (minus-61 Celsius).
But shortly after that historic bout of cold, the sea ice extent surrounding the continent shrunk to its smallest extent just last month.
Amid all of the variability in Antarctica, fingerprints of human-caused climate change are still evident. Its western ice sheet is losing mass while western parts of the continent and the peninsula are among the fastest-warming regions on Earth.
Warm ocean temperatures threaten to destabilize Antarctica’s Thwaites Glacier, a slab the size of Florida that contributes about 4 percent of annual global sea level rise.
The historically high temperatures in Antarctica follow a pulse of exceptional warmth on the planet’s opposite end. On Wednesday, temperatures near the North Pole catapulted 50 degrees above normal, close to the melting point.
DATE: March 15, 2022
SOURCE: Inside Climate News
Methane emissions from coal mines worldwide exceed those from the global oil or gas sectors and are significantly higher than prior estimates by the Environmental Protection Agency and the International Energy Agency, a new Global Energy Monitor report concludes.
“The numbers just aren’t adding up,” Ryan Driskell Tate, the report’s author, said of coal mine methane emission estimates when compared to those in prior reports. “It’s an area that has dodged a lot of scrutiny.”
Coal mining emits 52 million metric tons of methane per year, more than is emitted from either the oil sector, which emits 39 million tons, or the gas industry, which emits 45 million tons, according to the report, published Tuesday.
Methane, the primary component of natural gas, is a potent greenhouse gas and the second leading driver of climate change after carbon dioxide. On a unit-per-unit basis, methane is more than 80 times as powerful at warming the planet as carbon dioxide over its first 20 years in the atmosphere. The gas slowly accumulates in coal seams as organic matter is converted to coal, a process that can take millions of years.
Methane emissions from coal mining worldwide are comparable to the vast carbon dioxide emissions from burning coal at over 1,100 coal-fired power plants in China over the near term, the report concludes. China, the world’s largest greenhouse gas emitter, derived more than 60 percent percent of its power in 2020 from burning coal, compared to about 19 percent in the United States.
“We all know that the oil and gas industry emits a lot of methane and that coal plants in China are a major source of CO2 emissions,” said Driskell Tate, the energy monitor’s project manager for its Global Coal Mine Tracker. “The most surprising thing about this report is just realizing that coal mining has a comparable climate impact.”
Measuring emissions from approximately 2,300 coal mines in operation worldwide, the Global Energy Monitor report found emissions were 50 percent higher than a 2019 estimate by the EPA and 20 percent higher than an estimate earlier this year by the International Energy Agency. Both the EPA and IEA estimates relied on national averages rather than more specific figures from individual mines.
Other prior estimates for global coal mine methane emissions were even higher than those in the current report. However, the Global Energy Monitoring report is the first to take a detailed look at emissions from individual mines.
The current analysis drew data from the organization’s Coal Mine Tracker, a database that includes detailed information on nearly all coal mines worldwide, including the type and volume of coal extracted from each. The database also includes the depth of each mine, which can play a key role in how much methane a mine releases.
“One of the biggest contributions of this report is the level of detail and information that they provide about individual coal mines across the globe,” said Scot Miller, an environmental health and engineering professor at Johns Hopkins University. “If we want to mitigate these emissions, we need to know more than country level emissions. We need to know where these mines are, and how much methane is coming out of each mine so that we can develop effective mitigation strategies.”
The information on individual mines was combined with the Model for Calculating Coal Mine Methane, a method of calculating emissions developed by researchers at the Pacific Northwest National Laboratory, the EPA and other industry experts. The report found that some high-emitting mines can emit 67 times more methane than similarly sized mines.
China is far and away the leading source of coal mine methane emissions, the report said, warning that additional mines currently under development in China and other Asian countries will fuel additional warming.
DATE: December 14, 2021
It’s almost a mantra in climate science: The Arctic is warming twice as fast as the rest of the world. But that figure, found in scientific studies, advocacy reports, the popular press, and even the 2021 U.N. climate assessment, is incorrect, obscuring the true toll of global warming on the north, a team of climate scientists reports this week. In fact, the researchers say, the Arctic is warming four times faster than the global average.
“Everybody knows [the Arctic] is a canary when it comes to climate change,” says Peter Jacobs, a climate scientist at NASA’s Goddard Space Flight Center, who presented the work on 13 December at a meeting of the American Geophysical Union. “Yet we’re misreporting it by a factor of two. Which is just bananas.”
Researchers have long known the world warms faster in the far north, because of a phenomenon known as Arctic amplification. The drivers of amplification include increased solar heating, as dark ocean water replaces reflective sea ice, along with occasional intrusions of tropical heat, carried to the Arctic by “atmospheric rivers,” narrow parades of dense clouds that drag water vapor northward.
Jacob’s co-authors include researchers who oversee several influential global temperature records, and they noted the faster Arctic warming as they prepared to release the global temperature average for 2020. NASA’s internal peer reviewer challenged the higher figure, suggesting the scientific literature didn’t support it. But the researchers have found the four times ratio holds in record sets from both NASA (3.9) and the United Kingdom’s Met Office (4.1), and they hope to soon include the Berkeley Earth record. (Their work also has company: In July, a team at the Finnish Meteorological Institute posted a preprint also arguing for the four times figure.)
The researchers found Arctic warming has been underestimated for a couple of reasons. One is climate scientists’ tendency to chop each hemisphere into thirds and label the area above 60°N as the “Arctic”—an area that would include, for example, most of Scandinavia. But the true definition of the Arctic is defined by Earth’s tilt. And, as has been known for centuries, the Arctic Circle is a line starting at 66.6°N. When researchers lump in the lower latitudes, “you’re diluting the amount of Arctic warming you’re getting,” Jacobs says. “That is not a trivial thing.”
The other difference is the choice of time periods over which the warming rate is calculated. Jacobs and his colleagues focused on the past 30 years, when a linear warming trend emerged for the Arctic. Analyses that look at longer term trends see less divergence between the Arctic and the world. That’s because before 1990, the Arctic’s temperatures fluctuated, and even cooled for decades because of air pollution, including light-blocking sulfate aerosols that swept in from the northern midlatitudes, says Mark England, a climate scientist at the University of California, Santa Cruz, who is unaffiliated with the new work. As the world moves off fossil fuels and curbs pollution, he says, “this scenario is not going to repeat itself again.”
Overall, the researchers make a valuable point, England says. “I’m one of the people guilty of using the 60° mark. I guess a large number of people are.” One open question, he adds, is how much of the fast Arctic warming comes from human-driven climate change versus natural variability. Some of the Arctic temperature rise could be due to multidecadal temperature swings in the Atlantic Ocean in the 20th century, which some scientists believe are driven by the ocean’s intrinsic variability. Even so, “introducing this rigor in terms of 66° is a welcome development and I’ll certainly be doing that going forward,” England says.
Mark Serreze, director of the U.S. National Snow and Ice Data Center, also welcomes the new analysis but points out that Arctic amplification is never a fixed ratio. As the researchers showed, the time span used to calculate the rate matters, as does the latitude and season—amplification is far larger in the winter. Serreze adds that Arctic warming has always been more uncertain than the rest of the world, because of the spottiness of the observational records. “As a result, I’m always in favor of looking at it as a range,” he says. “Two times to four times.”
Wherever the exact ratio of amplification sits, its influence is undeniable, researchers say. Thawing permafrost is undermining Indigenous villages, summer sea ice is vanishing, and water is sluicing off Greenland’s ice sheet in record amounts.
The team also sees the work as a cautionary tale, says Jacobs, who also works on communications for NASA. “When something is changing as quickly as the climate, numbers can get old and outdated quickly,” he says. “Before you realize it, you’re misinforming people by a factor of two.”
DATE: August 19, 2021
SNIP: For the first time on record, precipitation on Saturday at the summit of Greenland — roughly two miles above sea level — fell as rain and not snow.
Temperatures at the Greenland summit over the weekend rose above freezing for the third time in less than a decade. The warm air fueled an extreme rain event that dumped 7 billion tons of water on the ice sheet, enough to fill the Reflecting Pool at the National Mall in Washington, DC, nearly 250,000 times.
It was the heaviest rainfall on the ice sheet since record keeping began in 1950, according to the National Snow and Ice Data Center, and the amount of ice mass lost on Sunday was seven times higher than the daily average for this time of year.
Ted Scambos, a senior research scientist at the National Snow and Ice Data Center at the University of Colorado, said this is evidence Greenland is warming rapidly.
“What is going on is not simply a warm decade or two in a wandering climate pattern,” Scambos told CNN. “This is unprecedented.”
The National Science Foundation’s Summit Station is located at the highest point on the Greenland ice sheet, where scientists can observe Arctic weather and changes in the ice. The station has been staffed year-round to observe extreme changes since 1989. The majority of the weekend’s rain fell from the southeast coast of Greenland up to the Summit Station.
Jennifer Mercer, program officer for the Office of Polar Programs at the National Science Foundation, said because of the significant rain event, operations at the Summit Station would need to change: “It means that we need to consider weather events that we have not had to deal with before in the history of our operations there,” she told CNN.
“Increasing weather events including melting, high winds, and now rain, over the last 10 years have occurred outside the range of what is considered normal,” Mercer said. “And these seem to be occurring more and more.”
According to Mercer, the rain will have a lasting effect on the properties of the snow, leaving a crust of ice behind that will absorb more energy from the sun, until it gets buried by snow. Scambos said this crusty layer will also be a barrier that prevents the downward draining of melt water, which will then flood the surface of the ice sheet and initiate run off at higher elevations.
Because of the layer of ice it created, the weekend’s rainfall event “will be visible in ice core records in the future,” Mercer said.
SOURCE: The Guardian
DATE: August 13, 2021
SNIP: At the peak of the whaling industry, in the late 1800s, North Atlantic right whales were slaughtered in their thousands. With each carcass hauled on to the deck, whalers were taking more than just bones and flesh out of the ocean. The slaughtered whales had unique memories of feeding grounds, hunting techniques and communication styles; knowledge acquired over centuries, passed down through the generations, and shared between peers. The critically endangered whale clings on, but much of the species’ cultural knowledge is now extinct.
Whales are among the many animals known to be highly cultural, says Prof Hal Whitehead, a marine biologist at Dalhousie University. “Culture is what individuals learn from each other, so that a bunch of individuals behave in a similar way,” he says.
North Atlantic right whales are no longer found in many of their ancestral feeding grounds. Whitehead suspects this may be because the cultural knowledge of these places was lost when populations were wiped out by whaling. This loss could spell trouble for the species if human activity degrades their remaining feeding grounds, making it hard for the whales to predict where good hunting is. “The more possible feeding grounds they have, the more likely they are to find somewhere they can get the food they need,” he says.
Animal culture is not limited to the ocean. Birds, bees, naked mole-rats, fish and even fruit flies are among those that have been found to learn socially and create cultures. As the list grows, researchers are starting to understand animal culture as critical to many conservation efforts.
Whitehead was an early voice calling for animal culture to be taken seriously in conservation. This is because cultural diversity gives a species a larger behavioural toolkit when facing new challenges, he argues. “We recognise this with humans, that the diversity of our cultures is a strength.”
Whitehead is a member of the Committee on the Status of Endangered Wildlife in Canada, a body that decides which species are endangered. “The most difficult thing we do is to decide how to divide a population of a species up,” he says. With caribou, for example, plains caribou are doing better than mountain caribou. “Do we assess the mountain caribou differently from the others?” Whitehead asks.
Typically, this decision is made by assessing how genetically different the groups are. “One of the things I’ve been pushing is the idea that cultural information is also important.”
Whitehead’s research into whale culture provided a lightbulb moment for Philippa Brakes, a research fellow at Whale and Dolphin Conservation. Brakes, a PhD student at the University of Exeter, published a paper with colleagues in April, which argues that conservation efforts should consider how culture affects reproduction, dispersal and survivorship.
Understanding who holds cultural knowledge in a population can be key, says Brakes, who cites African elephant herds as an example. “The age of the matriarch in the herd has a significant [positive] influence on the fertility rate of the younger females,” she says. “The [matriarch] female’s experience of where water holes are, where good foraging is, and also which other social units are friendly has a demonstrable knock-on effect on the fertility rate of the younger females in her herd.
“If you remove individuals who have knowledge, through hunting for example, that can have a much wider knock-on effect than just minus one from your population.”
“We are just starting to understand what culture is in other species and just starting to develop methods for measuring and analysing culture, as we are seeing it disappear before our eyes.”
SOURCE: New York Times
DATE: August 12, 2021
SNIP: It is seen by many as the clean energy of the future. Billions of dollars from the bipartisan infrastructure bill have been teed up to fund it.
But a new peer-reviewed study on the climate effects of hydrogen, the most abundant substance in the universe, casts doubt on its role in tackling the greenhouse gas emissions that are the driver of catastrophic global warming.
The main stumbling block: Most hydrogen used today is extracted from natural gas in a process that requires a lot of energy and emits vast amounts of carbon dioxide. Producing natural gas also releases methane, a particularly potent greenhouse gas.
And while the natural gas industry has proposed capturing that carbon dioxide — creating what it promotes as emissions-free, “blue” hydrogen — even that fuel still emits more across its entire supply chain than simply burning natural gas, according to the paper, published Thursday in the Energy Science & Engineering journal by researchers from Cornell and Stanford Universities.
“To call it a zero-emissions fuel is totally wrong,” said Robert W. Howarth, a biogeochemist and ecosystem scientist at Cornell and the study’s lead author. “What we found is that it’s not even a low-emissions fuel, either.”
To arrive at their conclusion, Dr. Howarth and Mark Z. Jacobson, a professor of civil and environmental engineering at Stanford and director of its Atmosphere/Energy program, examined the life cycle greenhouse gas emissions of blue hydrogen. They accounted for both carbon dioxide emissions and the methane that leaks from wells and other equipment during natural gas production.
The researchers assumed that 3.5 percent of the gas drilled from the ground leaks into the atmosphere, an assumption that draws on mounting research that has found that drilling for natural gas emits far more methane than previously known.
They also took into account the natural gas required to power the carbon capture technology. In all, they found that the greenhouse gas footprint of blue hydrogen was more than 20 percent greater than burning natural gas or coal for heat.
Such findings could alter the calculus for hydrogen. Over the past few years, the natural gas industry has begun heavily promoting hydrogen as a reliable, next-generation fuel to be used to power cars, heat homes and burn in power plants.
In the United States, Europe and elsewhere, the industry has also pointed to hydrogen as justification for continuing to build gas infrastructure like pipelines, saying that pipes that carry natural gas could in the future carry a cleaner blend of natural gas and hydrogen.
The latest study added to the evidence, said Drew Shindell, a professor of earth science at Duke University. Dr. Shindell was the lead author of a United Nations report published this year that found that slashing emissions of methane, the main component of natural gas, is far more vital in tackling global warming than previously thought.
SOURCE: The Guardian
DATE: August 3, 2021
SNIP: With climate change threatening the sea ice habitat of Emperor penguins, the US Fish and Wildlife Service today announced a proposal to list the species as threatened under the Endangered Species Act.
“The lifecycle of Emperor penguins is tied to having stable sea ice, which they need to breed, to feed and to molt,” said Stephanie Jenouvrier, a penguin ecologist at the Woods Hole Oceanographic Institution.
Research published Tuesday in the journal Global Change Biology found that by 2100, 98 per cent of Emperor penguin colonies may be pushed to the brink of extinction, if no changes are made to current rates of carbon emissions and climate change.
Around 70 per cent of colonies will be in danger sooner, by 2050.
The new study looked at overall warming trends and the increasing likelihood of extreme weather fluctuations due to global warming.
And it noted that extremely low levels of sea ice in 2016 led to a massive breeding failure of an Emperor penguin colony in Antarctica’s Halley Bay.
That year, seasonal sea ice broke up before penguin chicks had time to develop waterproof adult feathers, and about 10,000 baby birds drowned, Jenouvrier said. The colony did not recover afterward.
Emperor penguins breed exclusively in Antarctica during winter. They endure temperatures of minus 40 degrees Celsius and wind speeds approaching 144 kilometres per hour by huddling together in groups of several thousand birds. But they can’t survive without sufficient sea ice.
“These penguins are hard hit by the climate crisis, and the US government is finally recognising that threat,” said Sarah Uhlemann, international program director at the non-profit Centre for Biological Diversity.
The US government has previously listed species outside the country as threatened, including the polar bear, which lives in Arctic regions and is also imperilled by climate change and sea ice loss.
Emperor penguins — the world’s largest penguins — currently number about 270,000 to 280,000 breeding pairs, or 625,000 to 650,000 individuals. The proposed listing will be published in the Federal Register on Wednesday to open to a 60-day public comment period.
Listing the bird provides protections such as prohibition against importing them for commercial purposes. Potential impacts on penguins must also be evaluated by US marine fisheries currently operating in Antarctica.
“Climate change, a priority challenge for this Administration, impacts a variety of species throughout the world,” said Martha Williams, principal deputy director of the wildlife service.
“The decisions made by policymakers today and during the next few decades will determine the fate of the Emperor penguin.”
SOURCE: The Guardian
DATE: July 30, 2021
SNIP: Greenland’s vast ice sheet is undergoing a surge in melting, with the amount of ice vanishing in a single day this week enough to cover the whole of Florida in two inches of water, researchers have found.
The deluge of melting has reached deep into Greenland’s enormous icy interior, with data from the Danish government showing that the ice sheet lost 8.5bn tons of surface mass on Tuesday alone. A further 8.4bn tons was lost on Thursday, the Polar Portal monitoring website reported.
The scale of disappearing ice is so large that the losses on Tuesday alone created enough meltwater to drown the entire US state of Florida in two inches, or 5cm, of water. Ice that melts away in Greenland flows as water into the ocean, where it adds to the ongoing increase in global sea level caused by human-induced climate change.
“It’s a very high level of melting and it will probably change the face of Greenland, because it will be a very strong driver for an acceleration of future melting, and therefore sea-level rise,” said Marco Tedesco, a glacier expert at Columbia University and adjunct scientist at Nasa.
Tedesco said a patch of high pressure is sucking and holding warmer air from further south “like a vacuum cleaner” and holding it over eastern Greenland, causing an all-time record temperature of 19.8C in the region on Wednesday. As seasonal snow melts away, darker core ice is exposed, which then melts and adds to sea level rise.
“We had these sort of atmospheric events in the past but they are now getting longer and more frequent,” Tedesco said.
“The snow is like a protective blanket so once that’s gone you get locked into faster and faster melting, so who knows what will happen with the melting now. It’s amazing to see how vulnerable these huge, giant areas of ice are. I’m astonished at how powerful the forces acting on them are.”
Greenland’s melting season usually lasts from June to August. The Danish government data shows that the island has lost more than 100bn tons of ice since the start of June this year and while the severity of melting is less than in 2019 – when 11bn tons of ice was lost in a single day – the area affected is much larger in 2021.
This rate of ice loss, which is accelerating as temperatures continue to increase, is changing ocean currents, altering marine ecosystems and posing a direct threat to the world’s low-lying coastal cities, which risk being inundated by flooding. A 2019 research paper found the Greenland ice sheet could add anything between 5cm and 33cm to global sea levels by the end of the century. The world is on track for “the mid to upper end of that”, Lipovsky said.
SOURCE: The Guardian
DATE: July 25, 2021
SNIP: In 1963, two years before I was born, Rachel Carson warned us in her book Silent Spring that we were doing terrible damage to our planet. She would weep to see how much worse it has become. Insect-rich wildlife habitats, such as hay meadows, marshes, heathland and tropical rainforests, have been bulldozed, burned or ploughed to destruction on a vast scale. The problems with pesticides and fertilisers, she highlighted, have become far more acute, with an estimated 3m tonnes of pesticides now going into the global environment every year. Some of these new pesticides are thousands of times more toxic to insects than any that existed in Carson’s day. Soils have been degraded, rivers choked with silt and polluted with chemicals. Climate change, a phenomenon unrecognised in her time, is now threatening to further ravage our planet. These changes have all happened in our lifetime, on our watch, and they continue to accelerate.
Few people seem to realise how devastating this is, not only for human wellbeing – we need insects to pollinate our crops, recycle dung, leaves and corpses, keep the soil healthy, control pests, and much more – but for larger animals, such as birds, fish and frogs, which rely on insects for food. Wildflowers rely on them for pollination. As insects become more scarce, our world will slowly grind to a halt, for it cannot function without them.
Insects have been around for a very long time. Their ancestors evolved in the primordial ooze of the ocean floors, half a billion years ago. They make up the bulk of known species on our planet – ants alone outnumber humans by a million to one – so if we were to lose many of our insects, overall biodiversity would of course be significantly reduced. Moreover, given their diversity and abundance, it is inevitable that insects are intimately involved in all terrestrial and freshwater food chains and food webs. Caterpillars, aphids, caddisfly larvae and grasshoppers are herbivores, for instance, turning plant material into tasty insect protein that is far more easily digested by larger animals. Others, such as wasps, ground beetles and mantises, occupy the next level in the food chain, as predators of the herbivores. All of them are prey for a multitude of birds, bats, spiders, reptiles, amphibians, small mammals and fish, which would have little or nothing to eat if it weren’t for insects. In their turn, the top predators such as sparrowhawks, herons and osprey that prey on the insectivorous starlings, frogs, shrews or salmon would themselves go hungry without insects.
The loss of insect life from the food chain would not just be catastrophic for wildlife. It would also have direct consequences for the human food supply. … 87% of all plant species require animal pollination, most of it delivered by insects. The colourful petals, scent and nectar of flowers evolved to attract pollinators. Without pollination, wild flowers would not set seed, and most would eventually disappear. There would be no cornflowers or poppies, foxgloves or forget-me-nots. But an absence of pollinators would have a far more devastating ecological impact than just the loss of wild flowers. Approximately three-quarters of the crop types we grow also require pollination by insects, and if the bulk of plant species could no longer set seed and died out, then every community on land would be profoundly altered and impoverished, given that plants are the basis of every food chain.
Insects are also intimately involved in the breakdown of organic matter, such as fallen leaves, timber and animal faeces. This is vitally important work, for it recycles the nutrients, making them available once more for plant growth. Most decomposers are never noticed. For example, your garden soil – and particularly your compost heap, if you have one – almost certainly contains countless millions of springtails (Collembola). These minute, primitive relatives of insects, often less than 1mm long, are named for their clever trick of firing themselves as high as 100mm into the air to escape predators. This army of minuscule high-jumpers does an important job, nibbling on tiny fragments of organic matter and helping to break them up into even smaller pieces which are then further decomposed by bacteria, releasing the nutrients for plants to use.
The American biologist Paul Ehrlich likened the loss of species from an ecological community to randomly popping out rivets from the wing of an aeroplane. Remove one or two and the plane will probably be fine. Remove 10, or 20 or 50, and at some point that we are entirely unable to predict, there will be a catastrophic failure, and the plane will fall from the sky. Insects are the rivets that keep ecosystems functioning.
In October 2019 a different group of German scientists published their findings from a study of insect populations in German forests and grasslands over 10 years from 2008 to 2017. The study’s results were deeply troubling. Grasslands fared worst, losing on average two-thirds of their arthropod biomass (the insects, spiders, woodlice and more). In woodlands, biomass dropped by 40%.
What about elsewhere? Is there something peculiar going on in Germany? It seems highly unlikely. Perhaps the best-studied insect populations in the world are the UK’s butterflies. They are recorded by volunteers as part of the Butterfly Monitoring Scheme, the largest and longest-running scheme of its kind in the world. The trends it reveals are worrying. Butterflies of the “wider countryside” – common species found in farmland, gardens and so on, such as meadow browns and peacocks – fell in abundance by 46% between 1976 and 2017. Meanwhile, habitat specialists, fussier species that tend to be much rarer, such as fritillaries and hairstreaks, fell by 77%, despite concerted conservation efforts directed at many of them.
Worldwide, although the bulk of insect species – the flies, beetles, grasshoppers, wasps, mayflies, froghoppers and so on – are not systematically monitored, we often have good data on population trends for birds that depend on insects for food, and these are mostly in decline. For example, populations of insectivorous birds that hunt their prey in the air (ie the flying insects that have decreased so much in biomass in Germany) have fallen by more than any other bird group in North America, by about 40% between 1966 and 2013. Bank swallows, common nighthawks (nightjars), chimney swifts and barn swallows have all fallen in numbers by more than 70% in the past 20 years.
In England, populations of the spotted flycatcher fell by 93% between 1967 and 2016. Other once-common insectivores have suffered similarly, including the grey partridge (-92%), nightingale (-93%) and cuckoo (-77%). The red-backed shrike, a specialist predator of large insects, went extinct in the UK in the 1990s. Overall, the British Trust for Ornithology estimates that the UK had 44m fewer wild birds in 2012 compared with 1970.
All the evidence above relates to populations of insects and their predators in highly industrialised, developed countries. Information about insect populations in the tropics, where most insects live, is sparse. We can only guess what impacts deforestation of the Amazon, the Congo, or south-east Asian rainforests has had on insect life in those regions. We will never know how many species went extinct before we could discover them.
DATE: July 21, 2021
SNIP: Twelve people have died after record-breaking rainfall flooded underground railway tunnels in China, leaving passengers trapped in rising waters.
Video shared on social media shows evening commuters just managing to keep their heads above water. Water is seen rushing onto platforms.
More than 500 people were eventually rescued from the tunnels in Henan province, officials said.
Days of rain have caused widespread damage and led to 200,000 evacuations.
Above ground, roads have been turned into rivers, with cars and debris swept along in fast moving currents. A number of pedestrians have had to be rescued.
In total, 25 people have died in Henan province and more than a dozen cities are affected. President Xi Jinping said on Wednesday that there had been “significant loss of life and damage to property”.
Several dams and reservoirs have breached warning levels, and soldiers have been mobilised to divert rivers which have burst their banks. Flights and trains in many parts of Henan have also been suspended.
In the provincial capital Zhengzhou, the equivalent of a year’s average rainfall has fallen in just three days.
On Tuesday, some of the city’s flood defences were overwhelmed and water began flowing down into the railway tunnels.
Survivors have described how water leaked through the doors, rising slowly from “our ankles to our knees to our necks”. “All of us who could, stood on the subway seats,” one woman wrote on Chinese social network site Weibo.
Henan has experienced “rare and severe rainfall” since Saturday, China’s meteorological authority said on Wednesday.
Zhengzhou saw 624mm of rainfall on Tuesday, with a third of that amount falling between 16:00 and 17:00 alone, which “smashed historical records”.
It forecasted that parts of the region would continue to see “severe or extremely severe storms” and that the heavy rain was likely to end only on Thursday.
Many factors contribute to flooding, but a warming atmosphere caused by climate change makes extreme rainfall more likely.