Economists Who Changed Thinking on Climate Change Win Nobel Prize


The ideas of William Nordhaus and Paul Romer have shaped today’s policies on greenhouse gas emissions.
Economists Who Changed Thinking on Climate Change Win Nobel Prize
William Nordhaus (left) and Paul Romer.

A pair of U.S. economists, William Nordhaus and Paul Romer, share the 2018 Nobel Prize in Economic Sciences for integrating climate change, and technological change, into macroeconomics, which deals with the behaviour of an economy as a whole.

Nordhaus, at the University of Yale in New Haven, Connecticut, is the founding father of the study of climate change economics. Economic models he has developed since the 1990s are now widely used to weigh the costs and benefits of curbing greenhouse gas emissions against those of inaction. His studies are central to determining the social cost of carbon, an attempt to quantify the total cost to society of greenhouse-gases, including hidden factors such as extreme weather and lower crop yields. The metric is increasingly used when implementing climate change policies.

“Nordhaus was in a position early on to think about climate change from a human welfare and well-being perspective,” says Ottmar Edenhofer, director of the Potsdam Institute for Climate Impact Research in Germany. “Without him, there wouldn’t be such a subject of climate economics.”

Romer, who is at the NYU Stern School of Business in New York, was honoured for his work on the role of technological change in economic growth. The economist is best-known for his studies on how market forces and economic decisions facilitate technological change. His ‘endogenous growth theory’, developed in the 1990s, opened new avenues of research on how policies and regulations can prompt new ideas and economic innovation.

And Romer’s work also has implications for policies relating to climate-change mitigation. “He showed clearly that unregulated free markets will not sufficiently invest in research and development activities,” says Edenhofer.

The Royal Swedish Academy of Sciences said in a statement: “William D. Nordhaus and Paul M. Romer have designed methods for addressing some of ourtime’s most basic and pressing questions about how we create long-term sustained and sustainableeconomic growth.”

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What’s in a Half a Degree? 2 Very Different Future Climates


A new IPCC report shows the impacts in the near future that can be avoided by limiting warming to 1.5 degrees Celsius instead of 2 degrees C.
What's in a Half a Degree? 2 Very Different Future Climates
Coral reefs, like this bleached specimen in Malaysia, could be virtually wiped out if global temperatures rise by 2 degrees C. A more limited warming of 1.5 degrees C would still cause 70 to 90 percent of reefs to disappear.

A mere half a degree could spell the difference between the Arctic being ice-free once a decade and once a century; between coral reefs being almost entirely wiped out and up to 30 percent hanging on; and between a third of the world’s population being exposed to extreme heat waves and a tenth.

These alternate futures were laid out last week in a new report from the Intergovernmental Panel on Climate Change (IPCC) that explores the possibility of limiting global temperature rise to 1.5 degrees Celsius above preindustrial times by 2100, instead of the 2-degree C upper limit agreed to in the landmark Paris agreement three years ago. The report exposes the closing window humanity has to choose which future it wants.

Preventing a temperature rise of 2 degrees C will be a major challenge, one that the current commitments from various countries will likely be unable to meet. And that is before Pres. Donald Trump pulls the U.S. out of the agreement. But the report says a 1.5-degree C limit is not impossible—although it will require immediate and drastic action, because the current pace of emissions would breach that level between 2030 and 2052. The most likely scenario for achieving that goal may require blowing past it, and then sucking carbon dioxide out of the atmosphere to bring temperatures back in line.

With disruptions to the climate system already being felt now amid just under 1 degree C of warming, even the 1.5-degree C goal seems poised to bring major negative impacts. Preventing another half degree of warming on top of that, however, would spare entire ecosystems, cities and vulnerable populations from exponentially worse damage. “We still have choices to make; we’ve seen some of the leading-edge damage already,” says Kim Cobb, a climate scientist at Georgia Institute of Technology, who is an author on the next major IPCC report.

Here are some of the climate consequences that can be avoided if warming is limited to 1.5 degrees C:

Heat: Rising average temperatures have a clear connection to how often heat waves happen, and how bad they get when they do. Studies have already shown the fingerprints of global warming on major heat waves in today’s climate, and things will only get worse as temperatures on the hottest days rise faster than the global average. One study cited in the new report used climate models to see how the share of the world’s population exposed to a heat wave (one with a 5 percent chance of occurring in any given year) would change. That number increased from less than 10 percent of the population now to 50 percent with 1.5 degree C of warming, and more than 70 percent at 2 degrees C.

Ecosystems: Coral reefs have already been battered by warming and acidifying oceans, with widespread bleaching in recent years. Reefs have one of the bleaker future outcomes: a temperature rise of 2 degrees C would eliminate 99 percent of today’s reefs whereas 1.5 degrees C could save a sliver of them, with losses between 70 and 90 percent. Other animals face major losses in places to live. The amount of climatically suitable habitat lost by vertebrates and plants would double from a 1.5- to 2-degree C regime, and triple for invertebrates.

Arctic: The Arctic has already warmed at about double the rate of the planet as a whole, causing permafrost to thaw and sea ice to steadily melt. The jump from 1.5 to 2 degrees C could mean an extra 1.5 million to 2.5 million square kilometers of permafrost disappear, while the Arctic Ocean would go from seeing ice-free conditions in the summer once every 100 years to once every 10.

Food and Water: Warming temperatures also threaten the water and food sources humans depend on. Allowing the global temperature to rise by 2 degrees C could double the losses in annual ocean fish catches, up the number of people exposed to water stress by 50 percent and increase the declines in the yields of key staple crops such as maize, rice and wheat.

Credit: Amanda Montañez; Sources: “Extreme Heat Waves under 1.5° C and 2° C Global Warming,” by Alessandro Dosio et al., in Environmental Research Letters, Vol. 13, No. 5; April 25, 2018 (heat wave data); Carbon Brief, “The Impacts of Climate Change at 1.5 C, 2 C and Beyond”; accessed October 12, 2018, https://interactive.carbonbrief.org/impacts-climate-change-one-point-five-degrees-two-degrees/# (rainfall data); Intergovernmental Panel on Climate Change, “Special Report on Global Warming of 1.5° C”; October 8, 2018 (arctic, habitat loss, and coral reef data)

Your Antidepressants Are Ending Up in The Environment, Bathing Fish in a ‘Drug Soup’


For millions of people around the globe, antidepressants are vital medications. Unfortunately, once those pharmaceuticals have done their job inside our bodies, their biochemical effects don’t stop there.

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Two researchers from the University of Portsmouth are calling for greater awareness of the risks posed by our prescriptions once they’ve been flushed into the environment, in the hope we might find ways to reduce their ecological impact.

“Our aquatic life is bathing in a soup of antidepressants,” says marine biologist Alex Ford from Portsmouth’s Institute of Marine Biology.

“Antidepressant and antianxiety medications are found everywhere, in sewage, surface water, ground water, drinking water, soil, and accumulating in wildlife tissues.”

And there’s a growing pile of evidence suggesting this ‘soup’ of antidepressants and their break-down products is taking its toll on marine life.

More frightening still are indications that it doesn’t take a high concentration for effects to appear.

“Laboratory studies are reporting changes such as how some creatures reproduce, grow, the rate at which it matures, metabolism, immunity, feeding habits, the way it moves, its colour and its behaviour,” says Ford.

Several years ago, the researcher showed how low levels of selective serotonin reuptake inhibitors such as fluoxetine – the key compound in the antidepressant Prozac – altered the behaviour of amphipod shrimp, causing them to leave sheltered spots more often and risk being preyed upon.

Working with Helena Herrera, an expert in ethical pharmacology, Ford is calling for more research into the risks and benefits of psychotropic prescriptions for the environment in addition to human health.

There’s little question that mood medications help many people deal with chronic levels of clinical depression and anxiety. What is of concern is a growing number of people are turning to pharmacological treatments, increasing levels of psychotropic drugs in the environment.

A study published in 2016 found a 26 percent increase in the use of antidepressants among children and adolescents in the US from 2005 to 2012. The UK saw a 54 percent jump during the same period.

With roughly one in ten people across the Western world on long term courses of antidepressants, this upward trend has the potential to spark an environmental catastrophe.

Without adequate measures for eliminating these chemicals from our waste, we need to ask a hard question – do all of us really need to be medicated, or should we be encouraging alternatives in the name of healthier marine ecosystems?

Swapping pills for therapy or reducing their use won’t work for everybody, but as part of a multipronged approach it could help keep a cap on that growing concentration of psychotropic waste.

Disposal programmes that are tasked with collecting unused medications from patients are already active in many parts of the world, yet vary in their popularity. Improved education could make a significant difference there as well.

“Could educating the medical profession help improve the utility of take back programmes and patient behaviour with regard to drug waste?” the researchers ask.

They’re confident that even small steps would make a big difference.

Other contributions to a solution could include pharmacological companies themselves stepping up and taking a leading role in a ‘cradle-to-grave’ strategy for managing the journey beyond a medication’s delivery.

UK waste management services could also upgrade their infrastructure to reduce the levels of synthetic oestrogens in waste water, they suggest.

“These substances are not currently covered by existing regulations with regards to sewage management, and analytical methods for detection are just now becoming available,” the researchers write.

However we manage it, it’s clear that action is needed, and it’s a problem we can all do something about.

Getting a prescription to antidepressants is a big step forward for many people with a life-changing disorder. Sadly, it means our waterways and estuaries are getting a prescription as well.

UN gives 12-year deadline to crush climate change


Climate change activists holding a banner that reads '1POINT5 = LIFE LINE' during previous UN Climate Conference. /

Climate change activists holding a banner that reads ‘1POINT5 = LIFE LINE’ during previous UN Climate Conference.

The world’s politicians have just over a decade left to implement drastic transformations in their energy, food and transport systems that could avoid dangerous climate change, a report has revealed.

The report, published today by the UN’s Intergovernmental Panel on Climate Change, said that crucial policies to reduce global warming must be in place by 2030 to avoid the worst. If emissions continue at the current rate, 1.5 degrees of warming could be reached between 2030 and 2052, and temperatures would continue to rise steeply, the IPCC authors said.

According to the United States National Oceanic and Atmospheric Administration, Earth has already warmed by nearly a degree since 1900 due to carbon emissions from industry, farming, heating, and transport. Stabilising global warming to 1.5 degrees above pre-industrial level is possible, the authors of the report said. But, they added, meeting the goal will depend entirely on the political will of all countries.

“But it also comes with some wishful thinking that the messages are being taken up by the public, by policymakers and by governments,”

Hans-Otto Pörtner

The aim of the report was to follow up on the Paris Agreement, a set of targets to limit climate change signed at a UN summit in Paris, France, in 2015. Scientists have warned that, even if all pledges under the agreement are implemented, humans will still emit around 58 gigatonnes of CO2 in 2030, far beyond the 35gt needed to halt global warming at 1.5 degrees.

The report highlights a number of potential pathways to prevent further warming, including removing carbon from the atmosphere, phasing out coal and reducing food waste. “The preparation of this report […] was a benefit in itself,” said Hans-Otto Pörtner, an ecologist at Germany’s Alfred Wegener Institute, who chairs an IPCC working group. “But it also comes with some wishful thinking that the messages are being taken up by the public, by policymakers and by governments.”

The IPCC report pointed out that there would be significant differences between a 1.5 degree world and 2 degrees of global warming. Under a 2-degree scenario, the proportion of people exposed to heat waves at least once every five years would leap from 14 to 37 percent. This will increase ozone-related mortality and the spread of vector-borne diseases, such as malaria and dengue fever, the report warned.

Even under the 1.5-degree scenario, ocean fishing is expected to decline by 1.5 million tonnes a year. But this figure would double, were global mean temperatures to reach 2 degrees of additional warming, the report said.

However, the IPCC authors make it clear that some mitigation measures need to be carefully managed to avoid negative ‘trade-offs’. “Any poorly designed policy is going to have unexpected consequences,” says Joyashree Roy, an economics researcher at Jadavpur University in India, who coordinated the report’s summary for policymakers. “For example, if we adopted bioenergy at massive scale, this may lead to competition for land, which in turn may cause food prices to spike.”

Niklas Höhne, a co-founder of the NewClimate Institute think tank in the Netherlands, said that many transformations have already happened on a small scale. “One example is renewable energy, that has developed much faster than people thought only five years ago,” he told SciDev.Net. “Right now, renewables are so cheap that are outpricing coal even in countries like India, where people always thought this would never happen.”

Höhne concedes that the 1.5 degree target by itself is an aspirational goal, but that striving for it keeps global leaders aware of the problem. “Whether we reach it or not,” he said, “is not the most important question.”

Slow-Motion Ocean: Atlantic’s Circulation Is Weakest in 1,600 Years


If hemisphere-spanning currents are slowing, greater flooding and extreme weather could be at hand

Slow-Motion Ocean: Atlantic's Circulation Is Weakest in 1,600 Years

In recent years sensors stationed across the North Atlantic have picked up a potentially concerning signal: The grand northward progression of water along North America that moves heat from the tropics toward the Arctic has been sluggish. If that languidness continues and deepens, it could usher in drastic changes in sea level and weather around the ocean basin.

That northward flow is a key part of the larger circulation of water, heat and nutrients around the world’s oceans. Climate scientists have been concerned since the 1980s that rising global temperatures could throw a wrench in the conveyor belt–like system, with possibly stark climatic consequences. Sea levels could ratchet upward along the U.S. east coast, key fisheries could be devastated by spiking water temperatures and weather patterns over Europe could be altered.

Such concerns had been quelled over the last decade as climate models suggested this branch of the ocean’s circulatory system was not likely to see a rapid slowdown, which would slow any consequences. But two new studies, published Wednesday in the journal Nature, suggest the recent weakening spotted by ocean sensors is not just a short-term blip, as some had thought. Rather, it is part of a longer-term decline that has put the circulation at its weakest state in centuries. The results imply climate models are missing key pieces of the puzzle, and that ill effects could be on their way.

Which pieces might be missing, though, could determine how worrying this trend is. If models are not sensitive enough to the changes going on in the North Atlantic, “that sort of puts the warning flag a little higher,” says Thomas Delworth, an ocean and climate modeler at the National Oceanic and Atmospheric Administration who was not involved in the research.

The Atlantic meridional overturning circulation (AMOC) and the subpolar gyre, where ocean waters cool when the AMOC weakens. Credit: Nature

Running AMOC

The warm, salty waters of the tropical Atlantic cruise northward along the eastern U.S. before darting toward northwestern Europe (giving the British Isles a climate far balmier than Newfoundland at a similar latitude). As that segment of ocean flow, known as the Gulf Stream, pushes north, it cools and becomes denser and eventually sinks, forming the so-called deepwater that flows back southward along the ocean floor toward Antarctica.

This cycle, called the Atlantic Meridional Overturning Circulation (AMOC), plays a key role in moving heat around the planet as well as nutrients throughout the ocean. It also helps draw carbon dioxide from the atmosphere into the sea. In the Pacific Ocean equatorial heat is transported north and south toward both poles. But in the Atlantic “the heat is moving northward throughout the whole Atlantic Ocean,” says David Thornalley, a paleo-oceanographer at University College London and co-author of one of the new studies. The resulting heat imbalance between the Northern and Southern hemispheres determines several large climatic features, such as the latitude at which a key tropical rain belt is located, which impacts water supplies, precipitation for agriculture and the health of tropical ecosystems.

As global temperatures rise with the levels of heat-trapping gases in the atmosphere, the AMOC could be disrupted by an influx of freshwater from increasing precipitation in the North Atlantic and the melting of sea ice and glaciers on land. The added freshwater lowers the water density in the zone where deepwater forms, backing up and weakening the overall flow of the AMOC like a clogged sink. That slowdown means less heat is transported northward, leading to cooler ocean temperatures in a region below Greenland, and warmer temperatures off the U.S. east coast. That warming leads to higher sea levels along the coast and raises sea temperatures where economically valuable cold-loving species like cod and lobster live.

There are some indications the cold spot below Greenland can alter atmospheric patterns in a way that channels warm air over Europe, increasing the likelihood of sustained summer heat waves, says Levke Caesar, a PhD student at the Potsdam Institute for Climate Impact Research (PIK) and co-author of the other new study. The changing ocean temperatures from an AMOC slowdown could also potentially help lock in colder winter conditions over the eastern U.S., PIK’s Stefan Rahmstorf, a co-author of the same research, has posited, although the evidence there is not clear.

Until a little more than 10 years ago scientists did not have any direct measurements of the AMOC to see how it was actually responding to climate change. The deployment of the RAPID array of instruments (short for the U.K and U.S.–sponsored Rapid Climate Change program) across the Atlantic Basin has allowed that data to slowly trickle in, and “they’ve been revealing it is undergoing weakening,” Thornalley says. But the brief window of data offers no longer-term perspective. When that first data came in, scientists thought the weakening could be a temporary change resulting from the natural ups and downs of the climate, but were aware it could be part of a much longer decline.

Clues from the Past

To help resolve the uncertainty, the teams involved with the new studies turned to what are called paleoclimate markers, which capture past changes in Earth’s climate to see how these recent changes fit in. Thornalley and his colleagues used sediment cores collected from the ocean floor along the U.S. east coast to reveal how deep ocean currents linked to the AMOC have changed over time; stronger currents deposit larger grains of sediment. They also looked at tiny creatures fossilized in sediment cores—some of which had thrived in colder conditions, others in warmer ones—to see how ocean temperatures changed as the AMOC waxed and waned in strength. Caesar and Rahmstorf’s study used direct measurements of ocean temperatures going back to the late 19th century.

The two studies came to broadly similar conclusions: The AMOC is in a very weakened state—the most anemic it has been in the last 1,600 years, according to Thornalley’s results.

The studies differ on the timing of when that weakening began. Thornalley’s record, which spans those 1,600 years, suggests it started at the end of the little ice age, a period from about A.D. 1350 to 1850, when solar and volcanic influences depressed temperatures across the Northern Hemisphere and glaciers and ice sheets expanded. As the little ice age ended and temperatures warmed, ice melted and freshwater flooded into the North Atlantic. The results suggest the current state of the AMOC is the weakest it has been over that whole long record. Whether today’s state is just a continuation of that reaction or whether global warming has also started to chip in is not clear, he says. Caesar, meanwhile, put the turning point toward a weaker AMOC in the mid-20th century, suggesting it is due to the influence of human-caused warming. Her team’s record, however, does not extend as far back.

The two results are not mutually exclusive. Both records show broadly similar patterns in decline. “We think it’s quite remarkable that all the evidence is converging,” Thornalley says. But pinpointing the timing of the weakening trend would give better clues as to what is driving it as well as how quickly it is happening and how rapidly we might expect to see some of the resulting climate impacts.

Already, Thornalley says, it is clear the Gulf of Maine has its warmest temperatures in the last 1,600 years. There are also “tantalizing glimpses” of more rapid sea level rise along the U.S., he says.

The researchers are curious why climate models seem to be missing something in the AMOC process. They do not capture this past behavior and significant weakening. If the results of these studies bear out, Delworth says, it is possible the models are not sensitive enough to the changes in ocean freshwater that are happening or they are not factoring in all of the important changes that have impacted the circulation. A 2017 study that looked at what would happen if climate models did factor in that melt saw it caused a sharper response from the AMOC than had otherwise been suggested.

The greater cause for concern would be if models are incorrectly capturing the sensitivity of the system, Delworth says, because it means scientist have been underestimating how quickly the AMOC might respond. “It really depends on why the models don’t match the paleo results,” he says.

While modelers work to figure that out, Thornalley and others are trying to expand the paleoclimate record to see if the pattern they found shows up at other sites throughout the Atlantic and if they can extend it farther back in time. They are also looking for signs of how much freshwater may have triggered the weakening at the end of the little ice age.

Moving forward, the RAPID instruments will slowly help tease out the AMOC’s behavior. “It’s just that we have to wait a couple of years,” Caesar says, by which time some impacts may already be happening.

Your Rubber Ducky Is a Disgusting Biohazard, Loaded With Potential Pathogens


The nightmare is real.

It’s one of the happiest-looking, most unassuming objects in your home. It exists only to float and create smiles. But behind the buoyant facade lies a dirty, dangerous secret.

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New research reveals rubber ducks have a dark side that’s both figurative and literal, with scientists discovering these seemingly wholesome toys act as incubators for potentially pathogenic bacterial and fungal growths – which cling to the duck’s inner cavities in a mucky biofilm of filth.

Surprised? We probably shouldn’t be.

After all, we know we’re continually surrounded by bacteria traps in our daily lives, and items we associate with cleaning are actually the most unclean of all.

338 rubber duck bacteria trap 3(Eawag)

But it’s particularly unsettling to find out the rubber ducky is of these questionable objects, because it occupies a special place in our homes.

Unlike the rudimentary kitchen sponge – devoid of character or presence – rubber ducks are something we associate with happiness, laughter, innocence.

Children play with them, squeeze water out of them, even put them in their mouths.

In the new study, scientists led by the Swiss Federal Institute of Aquatic Science and Technology collected 19 real bath toys from Swiss households, and mimicked real-world conditions for six separate new toys, exposing them to clean and dirty bath water, mixed in with things like soap, human body fluids, and bacteria.

This cohort – rubber (actually plastic) ducks, crocodiles, and other bathtime toys – may have started out squeaky clean, but they didn’t stay that way for long.

338 rubber duck bacteria trap 3(Eawag)

After 11 weeks of simulated household use, all the toys were bisected in the lab, revealing between 5–75 million cells per square centimetre in the biofilm lining their inner surfaces.

Fungal species were detected in almost 60 percent of the real bath toys and in all the new toys exposed to dirty water, and potentially pathogenic bacteria were found in 80 percent of all the toys.

The results might sound disgusting, but in actuality, exposure to these microbial communities is kind of a mixed bag, the researchers say.

“This could strengthen the immune system, which would be positive,” explains microbiologist Frederik Hammes, “but it can also result in eye, ear, or even gastrointestinal infections.”

338 rubber duck bacteria trap 3(Eawag)

Ultimately, the team says more research needs to be done to figure out how potentially dangerous these bacterial and fungal biofilms could be – especially to children – and advise the potentials may be mitigated by cleaning toys after bathtime, by boiling and drying them, to minimise their capacity for incubation.

Or, you could look for bath toys that don’t have a squeaky hole that sucks in water, although, as the team highlights, this has its own drawbacks.

“The easiest way to prevent children from being exposed to bath toy biofilms is to simply close the hole,” they conclude, “but where is the fun in that?”

Fossils Reveal an Ancient Climate Catastrophe, And We Need to Pay Attention


Scott Wing had spent more than a decade in the badlands of Wyoming’s Bighorn Basin, most of it thirsty, sunburned, and down on his hands and knees, digging endlessly through the dirt.

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But he had never found anything like the fossil he now held in his hand – an exquisitely preserved leaf embossed on beige rock. Wing let out a jubilant laugh as he uncovered a second fossil and then a third. Each leaf was different from the others. Each was entirely new to him.

And then he started to cry.

This was exactly what he’d been searching for. When these strange fossils formed 56 million years ago, the planet was warming faster and more dramatically than at any point in its history – except the present.

Recounting the moment recently in his office at the Smithsonian’s National Museum of Natural History, Wing recalled the uneasy reaction of the field assistant with whom he’d been hiking. The young man looked understandably nervous that his supervisor was shedding tears over a handful of rocks.

“I said, ‘You just have to realize, I’ve been looking for this … since you were a kid. I’m unreasonably happy right now, but I’m not crazy,'” Wing chuckled. “So, that was the first really good set of plant fossils from the PETM. It was definitely a moment that I won’t forget.”

scott wing at bighorn basinScott Wing at Bighorn Basin (Laura Soul/The Washington Post)

The PETM is the Paleocene Eocene Thermal Maximum – an ungainly name for the time that’s considered one of Earth’s best analogues to this era of modern, human-caused global warming. In a matter of a few thousand years, huge amounts of carbon were injected into the atmosphere, causing global temperatures to rise between 5 and 8 degrees Celsius.

The rapid climate change disrupted weather, transformed landscapes, acidified oceans and triggered extinctions. It took more than 150,000 years for the world to recover.

If history is allowed to repeat itself, the consequences for modern life could be similarly long-lasting – which is why Wing is so determined to understand this ancient climate catastrophe.

“To me, it doesn’t lead me to be fearful,” Wing said. “It leads me to feel responsible. It leads me to feel that we need to be more informed.”

The first major evidence for the PETM was uncovered in the early 1990s by scientists looking at the transition from the Paleocene, the epoch after the extinction of the dinosaurs, to the Eocene, when modern mammal orders first emerged.

There was something strange about the thin band of sediment that represented the boundary between these two epochs: its ratio of carbon isotopes – different forms of the same element – was skewed.

Further research revealed that something between 4 trillion and 7 trillion tons of carbon – the rough equivalent of the planet’s entire current reserve of fossil fuels – had flooded the atmosphere in this period. It came from the decomposed remains of ancient algae and plants, so it contained a larger amount of carbon-12 – the isotope that is preferred for photosynthesis.

This “spike” in carbon-12 served as a marker of the PETM and allowed researchers to start tracking the effects of this sudden climate shift in rocks and fossils around the world.

Chalk deposits at the bottom of the ocean began to dissolve as carbon dioxide made seawater more acidic. Fossils of tiny, deep sea-dwelling creatures showed evidence of an oxygen shortage – a sign that the water was getting warmer.

Everywhere in the ocean, creatures adapted to the changed environment, or else they died out.

On land, mammals got smaller and smaller. Ancient ancestors of horses, tiny to begin with, shrunk 30 percent to the size of house cats. Abigail Carroll, a paleoclimatologist at the University of New Hampshire, said this was probably an adaptation to the warmer weather: Smaller bodies are easier to keep cool.

Weather also got wilder. Geologists have uncovered huge rocks that were carried long distances by intense floods – something that happens when dry spells are followed by extreme rains.

And then there are the plants in Wing’s collection at the National Museum of Natural History. Before the PETM, fossils suggest, Wyoming looked more like Florida – a lush, subtropical forest shaded by stately sycamores, silvery birches and waving palm trees.

But as the world warmed, the Bighorn Basin transformed. The fossils Wing finds from this period belong to plants that typically grow in hot, arid places even farther south – spindly bean plants and relatives of poinsettia and sumac.

These plants must have migrated north when the weather changed, following their preferred environment to ever higher latitudes.

A swarm of ravenous herbivores apparently followed. Many of Wing’s fossils are perforated with bite marks left behind by insects more numerous and diverse than the ones that preceded them.

The source of all this mayhem remains uncertain. Some have suggested the flood of carbon that set off the PETM came from volcanic eruptions or even a comet impact.

But the most popular theory suggests that reservoirs of solid methane buried in seafloor sediments were released when the ocean’s temperature and chemistry changed. Methane is a potent greenhouse gas, short-lived but harder-hitting than carbon dioxide.

Once it set global warming in motion, the rising temperatures may have triggered the release of even more methane and unlocked additional carbon sources – wildfires, shifting ocean currents, soil microbes that breathe out greenhouse gases – in a chain reaction that changed the planet.

To scientists today, many of the phenomena observed during the PETM will feel familiar – so familiar “it’s almost eerie,” Wing said.

Humans burning fossil fuels have produced the same kind of carbon isotope spike researchers find in 55-million-year-old rocks. The ocean has become about 30 percent more acidic and it’s losing oxygen – changes that are already triggering die-offs.

The world has witnessed dramatic weather extremes – deadly heat waves, severe storms, devastating droughts. In response to these shifts, plants and animals are showing up in new places at unusual times. There’s even evidence that some species, such as birds called red knots, are getting smaller as a result of the warmer climate.

Still, the past is an imperfect predictor of what might happen as the modern world continues to warm. For one thing, Earth on the eve of the PETM was already much hotter than it is today. With the poles unfrozen and the sea levels high, ancient creatures didn’t have to worry about the effects of melting ice, as we do today.

And the pace at which we are changing the climate outstrips anything in the geologic record. The carbon surge that set off the PETM unfolded over the course of as long as 5,000 years. At our current rate, humans will produce a comparable surge in a matter of a few centuries.

“In all the major ways it’s more perilous now than it would have been then,” Wing said.

But for scientists trying to predict our future peril, the PETM is an invaluable reference.

Jeff Kiehl, a senior scientist at the National Center for Atmospheric Research, uses research by Wing and others to test models of the interplay between carbon and climate.

“We don’t have data for the future but we do have data from the past,” Kiehl said. “This is where Scott’s work … has played a critical role.”

Data from the PETM and other times of global warming can be used to answer the questions that haunt modern climate scientists: How much will the Earth warm if atmospheric carbon doubles? What will happen to the world’s water as a result? How long will it take for things to return to normal?

This week, Wing and his colleagues at the Smithsonian have gathered 17 experts for a symposium on ancient climate. Over the course of two days, they will try to reconstruct a timeline of Earth’s temperature and atmospheric carbon levels since complex life began roughly a half-billion years ago.

“Science has finally gotten us to a point where we have some idea of what the consequences are of the things that we do,” Wing said.

“Now the question is, can we use that knowledge in something that starts to approach a wise way?”

Light pollution is altering plant and animal behaviour


Light pollution can be problematic for animals like the Cory’s shearwater. Image credit – Airam Rodríguez (Estación Biológica de Doñana CSIC), licensed under CC BY 4.0

You could call it fatal attraction. Drawn by artificial lights in our brightening night-time world, animals find their lives in peril.

Fledgling birds disorientated by lights can collide with human structures on the ground and then get hit by cars, or become more vulnerable to predation, starvation or dehydration. Or newly hatched turtles may set out in the opposite direction to the sea, exposing themselves to similar dangers.

And our skies are getting brighter. A recent study found that our planet’s artificially lit outdoor area grew by about 2% each year between 2012 and 2016, while already lit areas brightened at the same rate.

‘Global growth in lighting at that kind of level is quite profound,’ said Kevin Gaston, a professor of biodiversity and conservation at the University of Exeter, UK. ‘We know that lighting is getting steadily worse.’

Researchers say one big problem has been a lack of awareness about light pollution. That is growing, but in the meantime, certain factors are potentially heightening its impact.

For example, white light-emitting diodes (LEDs) have been swiftly replacing traditional outdoor lighting such as yellow sodium street lights because of their higher energy efficiency. But because they emit light across a broad part of the visible spectrum, LEDs can affect a wider range of photosensitive cells in different organisms.

‘The negative consequences of light pollution are as unknown by the population as those of smoking in the 80s.’

Professor Oscar Corcho, Universidad Politécnica de Madrid, Spain

In a project called ECOLIGHTS FOR SEABIRDS, which ran from 2014 to the end of 2016, researchers found that the threat to fledgling shearwaters of being grounded on Phillip Island in south-eastern Australia was higher from broader-spectra metal halide and LED lights than from sodium lights. This suggests that using certain types of lights in different areas could be used to limit the effects on these birds.

Grounded

Separate studies on the Spanish island of Tenerife found that half of the Cory’s shearwater fledglings grounded around lights were within 3 kilometres of their nest sites and tended to be from inland colonies.

Dr Airam Rodríguez, a postdoctoral researcher at Doñana Biological Station in Seville, Spain, who worked on the project, said that knowing such information makes it easier to do things such as arrange safe corridors between breeding colonies and the ocean.

Many effects of light pollution on such seabirds have been poorly understood before, because of factors such as their breeding in remote locations and the fact they need to be tracked at night. Advances in technology are helping though, with the team using miniature GPS trackers and nocturnal high-resolution satellite imagery to follow the birds’ routes.

Dr Rodríguez said his team is now using GPS to look in more detail at what happens to birds rescued after being grounded by lights during their first days out on the ocean. He would also like to look more into the physiology of their eyes to find out which wavelengths the birds are more sensitive to.

Another little-known facet has been how much artificial lighting affects whole communities of organisms rather than just individual species, but recent research shows the effects can be significant.

As part of a project called ECOLIGHT, which finished last year, researchers set up 54 outdoor experimental environments, known as mesocosms, at the University of Exeter. These took the form of mesh-covered containers that held different combinations of plants, invertebrates and types of lighting, or were unlit. From this, they discovered that lighting seemed to suppress the flowering of the trefoil Lotus pedunculatus, and, in turn, the pea aphid population that feeds on them.

The team found similar effects in an experiment with bean plants and aphids.

Container-based experiments at the University of Exeter showed that lighting seemed to suppress the flowering of pea and bean plants and affected the aphid population that feeds on them. Image credit - James Duffy

Container-based experiments at the University of Exeter showed that lighting seemed to suppress the flowering of pea and bean plants and affected the aphid population that feeds on them. Image credit – James Duffy

Pervasive

Prof. Gaston, who was principal investigator on ECOLIGHT and also used field experiments to investigate the impact of light pollution, said: ‘This leads to the conclusion that lighting is having pretty pervasive ecological impacts. The effects are exceedingly widespread and are shaping the way that communities are structured – which was something that people hadn’t observed before.’

He also pointed to other research showing that bud burst in trees can happen a week earlier in the brightest compared with the darkest areas. ‘When we’ve discovered these kinds of things for climate change and they’ve shifted by about a week, we’ve said that’s profoundly worrying,’ he said.

His team is now looking more into the impacts of different intensities and colours of lights to build a more detailed picture.

In addition, they are scouring through images of Earth photographed by astronauts on the International Space Station so they can map how the colours of lights are changing as cities introduce more white LEDs.

Prof. Gaston explained that satellites are effectively colour-blind to the shift to white light, so using the pictures that astronauts take is a good way to track this, with about half a million pictures taken at night between 2003 and 2015.

This work complements the Cities at Night project, a citizen science initiative that gets help from volunteers to classify, locate and georeference these pictures.

A composite image of the Earth at night shows changes in light intensity between 2012 and 2016 including, for example, rapid electrification in India. Image credit - NASA's Goddard Space Flight Center

A composite image of the Earth at night shows changes in light intensity between 2012 and 2016 including, for example, rapid electrification in India. Image credit – NASA’s Goddard Space Flight Center

Also involved in Cities at Night is the STARS4ALL project, coordinated by Oscar Corcho, a professor at the Universidad Politécnica de Madrid in Spain, which acts as a platform to raise awareness of the issues involved in light pollution and inspire further research and better planning in lighting programmes. It seeks to engage people through methods such as games, broadcasting of astronomical events and a citizen-sensor network of low-cost photometers for people to measure light pollution in their area.

‘The negative consequences of light pollution are as unknown by the population as those of smoking in the (19)80s,’ said Prof. Corcho. ‘It’s still a very difficult problem to understand. Light pollution does not have the same immediate effects over animals as other forms of pollution.’

Regulation

Prof. Corcho said that one of STARS4ALL’s main aims this year is to run a petition on its website to ask for more overarching regulation to avoid light pollution at an EU level. STARS4ALL will collect signatures from citizens and hopes to present the petition in Brussels by the end of the year.

He says the good news is that there are easy fixes. ‘There are good technology options. For instance, there are types of lamps that could be used that are both respectful to the environment in terms of light pollution and at the same time as energy-efficient as white LEDs.’ He cites PC amber LEDs, for example.

If we move to solve these issues, there might well be an added bonus for us all. ‘As an indirect result… our recommendations for public lighting may result in having more populated places where we can see more and more stars in our sky,’ said Prof. Corcho.

People Aren’t as Safe From Lead as Thought: Study


Long-term, low-level lead exposure may be linked with more than 256,000 premature deaths from heart disease in middle-aged and older Americans each year, according to a new study.

The researchers analyzed data from 14,300 people in the United States, covering nearly 20 years. All participants had a medical exam and a blood test for lead at the start of the study.

The findings revealed a link between low-level exposure and increased risk of premature death. Lead exposure has been associated with hardened arteries, high blood pressure and coronary heart disease, according to the researchers.

“Our study estimates the impact of historical lead exposure on adults currently aged 44 years old or over in the USA, whose exposure to lead occurred in the years before the study began,” said study lead author Dr. Bruce Lanphear. He’s a professor at Simon Fraser University in British Columbia, Canada.

Historical exposure occurs from lead present in the environment because of past use in fuel, paint and plumbing. There’s also ongoing exposure from foods, emissions from industrial sources and contamination from lead smelting sites and lead batteries, the researchers explained.

“Today, lead exposure is much lower because of regulations banning the use of lead in petrol, paints and other consumer products so the number of deaths from lead exposure will be lower in younger generations,” Lanphear said.

But efforts to reduce environmental lead exposure is still vital, he said.

“Our study calls into question the assumption that specific toxicants, like lead, have ‘safe levels,'” Lanphear said. Rather, he said, it “suggests that low-level environmental lead exposure is a leading risk factor for premature death in the USA, particularly from cardiovascular disease.”

The findings were published online March 12 in The Lancet Public Health journal.

Stemming the risk requires a range of public health measures, Lanphear said in a journal news release, such as “abating older housing, phasing out lead-containing jet fuels, replacing lead-plumbing lines and reducing emissions from smelters and lead battery facilities.”

Dr. Philip Landrigan, a professor at the Icahn School of Medicine at Mount Sinai in New York City, wrote an editorial published with the study.

“A recurrent theme in lead poisoning research has been the realization that lead has toxic effects on multiple organ systems at relatively low levels of exposure previously thought to be safe,” Landrigan wrote. “A key conclusion to be drawn from this analysis is that lead has a much greater impact on cardiovascular mortality than previously recognized.”

Lead Is Far Worse Than We Know


Story at-a-glance

  • Nearly 535,000 children have blood lead levels high enough to damage their health; 24 million homes still have lead-based paint and contaminated house dust; and nearly 5,300 water systems in the U.S. are in violation of lead and copper rules
  • Researchers analyzed 20 years of data from a nationally representative sample of over 14,000 people, finding a strong correlation between blood lead levels and cardiovascular disease and premature death
  • Adults and children experience negative health effects from lead exposure leading to neurological damage, endothelial dysfunction and cardiovascular disease
  • Reduce your exposure and monitor your health by having lead-based paint professionally eliminated, having your home water tested and your and your children’s blood lead levels measured

By Dr. Mercola

According to the U.S. Centers for Disease Control and Prevention (CDC)1 nearly 535,000 children between 1 and 5 years of age, have blood lead levels high enough to damage their health; 24 million homes contain lead-based paint and elevated levels of contaminated house dust. Costs to the community for lead poisoning in children include up to $53 billion in additional health care costs, tax revenue losses up to $35 billion, special education costs up to $146 million and the direct cost of crime, estimated at $1.7 billion.2

According to the CDC, there is no known identified safe blood lead level for children or adults.3 Children exposed to lead have an increased risk of damage to their nervous system, brain and cognitive development, slowed growth and development and hearing and speech problems.

Although lead is a well-recognized neurotoxin, the U.S. has not paid close attention to exposure over the years. In fact, in 1923 the country introduced leaded gasoline, which triggered near unfathomable repercussions for the global community. Recent research published in the Lancet Public Health Journal found lead levels in adults are strongly correlated with a higher risk of death from cardiovascular complications.4

Study Demonstrates Lead Is a Serious Threat to Children and Adults

Researchers gathered 20 years of data using a nationally representative sample of over 14,000 adults enrolled in the National Health and Nutrition Examination Survey between 1988 and 1994.5 Each of the participants underwent medical testing, including quantifying lead levels in their blood. After analyzing the data, researchers discovered a link between low-level exposure to lead and increased risk of premature death.6

In the past, lead exposure had been associated with high blood pressure, coronary artery disease and atherosclerosis. Researchers point out historical exposure to lead is based on past use of lead-based gasoline, paint and plumbing. Ongoing exposure from food, industrial emissions and water toxicity may also affect blood lead levels in younger children. Lead author of the study, Dr. Bruce Lanphear, professor at Simon Fraser University in Canada, commented:7

“Our study estimates the impact of historical lead exposure on adults currently aged 44 years old or over in the USA, whose exposure to lead occurred in the years before the study began … Today, lead exposure is much lower because of regulations banning the use of lead in petrol, paints and other consumer products so the number of deaths from lead exposure will be lower in younger generations.”

Although scientists have known the toxic effects of lead exposure for centuries, the number of people affected by the cardiovascular effects were surprising, even to the researchers. In the initial 14,000 respondents, 4,400 had died by 2011. From this the researchers calculated approximately 18 percent of deaths could have been prevented by reducing blood lead concentrations to 1.0 micrograms per deciliter.

The researchers extrapolated from the data more than 400,000 deaths in the U.S. every year could be linked lead exposure from all sources.8 Nearly 250,000 of those are the result of cardiovascular disease and 185,000 are related to coronary artery disease. These numbers are nearly 10 times greater than the current estimates of deaths related to lead in adults. Lanphear goes on to say:9

“Nobody had even tried to estimate the number of deaths caused by lead exposure using a nationally representative sample of adults. But if we’re underestimating the impact of lead exposure on cardiovascular disease mortality and other important outcomes beyond IQ, then it might have a big impact on the way we make investments in preventing lead poisoning exposure …

When you start looking at the risk across the entire range of people exposed, all of a sudden the number of affected people balloons. Mostly it’s a numbers thing — there are so many people in the low- to moderate-risk groups that, as long as there are some risks with low-level exposure, many more people are going to die or develop heart disease.”

Brain Cells and Blood Vessels

The scientists included deaths from multiple causes and not just those from heart disease. They found higher blood lead levels were tied to more than 410,000 deaths in the U.S. annually, which was 10 times more than was previously estimated and close to the 480,000 smokers who die every year.10 While smoking, lack of exercise and an unhealthy diet are contributors to cardiovascular disease, environmental factors may also have an impact on increasing your risk of heart problems.11

Although the most recent study has identified an unexpected number of people affected by lead poisoning and cardiovascular changes, previous research has demonstrated the effect lead has on endothelial cells and in crossing the blood-brain barrier. The cellular effect of lead in the brain occurs as it disrupts the blood-brain barrier and triggers encephalopathy and edema, primarily in the cerebellum.12

Infants are at greatest risk for developing cognitive impairments, but adults are also at risk of lead intoxication with higher blood lead levels. Lead-induced hypertension and cardiovascular disease is the result of several disruptions to the endothelial system. Chronic lead exposure promotes oxidative stress and limits nitric oxide availability, which in turn reduces flexibility of the endothelial wall.

Each of the following factors raises the risk for hypertension, endothelial dysfunction, arteriosclerosis and cardiovascular disease. As these changes also occur in the endothelium within the brain, they may possibly have an impact on cognition and risks for dementia in the elderly. Other research has demonstrated that lead:13,14

Generates superoxide and hydrogen peroxide, which in turn reacts with nitric oxide and produces peroxynitrites Stimulates vascular smooth muscle cell proliferation and phenotypic transformation
Disturbs vascular smooth muscle calcium signaling Modifies vascular response to vasoactive antagonists
Raises plasminogen activator inhibitor-1 production Suppresses proteoglycan production
Causes endothelial injury Impedes endothelial repair
Inhibits angiogenesis Promotes inflammation

Your Water Supply May Increase Your Risk of Contamination to Multiple Poisons

In a study gathering data from over 30 years, researchers found nearly 8 percent of Americans were drinking water that violates health standards.15 The study was the first to assess nationwide violations in drinking water quality, looking at violations in 17,900 community water systems. In any given year from 1982 to 2015, when data was collected, between 9 and 45 million people were affected.

More than 600,000 observations were made over the life of the study and were more likely to occur in low-income areas using public-owned water systems. Under the Safe Drinking Water Act of 1974 the Environmental Protection Agency (EPA) regulates water quality, but each state has different reporting mandates. Erik Olson, health program director at Natural Resources Defense Council, which analyzed the EPA’s data for its report, characterized the effect of the report:16

“Imagine a cop sitting, watching people run stop signs, and speed at 90 miles per hour in small communities and still doing absolutely nothing about it — knowing the people who are violating the law. And doing nothing. That’s unfortunately what we have now.”

According to the report, more than 5,300 water systems are in violation of lead and copper rules, yet states took action on only 817 cases and the EPA took action in just 88 cases.17 Even worse, the report revealed the EPA was aware many municipalities used loopholes to avoid detecting high lead levels, which means many more communities may be exposing their residents to potentially dangerous levels of lead.

Following an effort to save money, in August 2015, Virginia Tech scientists discovered Flint, Michigan’s, tap water was contaminated with lead at dangerously high levels. One woman reported her water tested 104 parts per billion (ppb) of lead, nearly seven times greater than the EPA’s limit of 15 ppb.18

Between 2014 and 2015, 87 people in Genesee County, Michigan, where Flint is located, contracted Legionnaires’ and 10 died. It was considered one of the worst outbreaks of Legionnaires’ in U.S. history.19 According to the county health director Jim Henry, state officials had blocked the CDC from investigating the outbreak.

Henry suspected Flint River water right from the start, but CDC protocols require an invitation from state officials. County officials requested help from the CDC, but they never showed up because state officials never issued the prerequisite invitation. Such extreme problems with water quality are not exclusive to Flint, as the EPA has not made their water testing and treatment standards into enforceable regulations.

This has left cities and states to police themselves. Yanna Lambrinidou, assistant professor in the science and technology studies department at Virginia Polytechnic Institute and State University, who advised the EPA on changes to federal water standards, commented on the possibility of another emergency, such as Flint, Michigan:20 “Do I expect more Flints to happen? I think it’s very, very possible. I worry tremendously about water in other cities.”

Leaded Gasoline Poisoned the Public

In this short video you’ll discover the history of how lead came to be added to gasoline, despite being one of the best known poisons from as early as 2,000 years ago until occupational poisonings occurred during the industrial revolution. For nearly 80 years, lead was used in gasoline, polluting the air children and adults breathed.

Although other less toxic solutions to an engine knock problem were available, lead was chosen as an additive to gasoline since it was the most profitable, and allowed the oil industry to control both the product and their profits. The push to remove lead from gasoline began with the work of the late Clair Patterson, Ph.D, a former geochemist for the California Institute of Technology.

He worked on the Manhattan Project, but is best known for his pioneering work in 1963 to establish the age of the Earth as 4.5 billion years old. He accomplished this by analyzing certain isotopes of lead. However, he struggled with conflicting results in his research until he realized the problem was caused by environmental lead pollution. It wasn’t until he analyzed an ancient pristine ice core sample taken from Greenland that he found the source of the problem.

He was able to determine ice layers corresponding to specific eras in time, such as the Roman era, the Industrial Revolution and the advent of leaded gasoline in the mid-1920s. In the core sample beginning in the 1920s he noted a major spike in lead concentrations. He was the first who fully appreciated lead gasoline had polluted every last corner of the globe. As a result, people worldwide were exposed to lead pollution with very serious health consequences.

Despite massive efforts to discredit him, Patterson pursued the elimination of lead from gasoline. The first hurdle was cleared in 1975 when the U.S. mandated the use of unleaded gasoline to protect catalytic converters. However, it was another 11 years before his persistence caused the complete removal of lead from all gasoline in the U.S As a result, blood lead levels in Americans dropped by nearly 80 percent by the late 1990s.

Strategies to Avoid Lead Exposure

Lead in the blood is typically measured using micrograms per deciliter (mcg/dL) or ppb. In the past, the CDC used levels of 40 mcg/dL as acceptable concentrations.21 This was reduced to 10 mcg/dL in the early 1990s, and then 5 mcg/dL in the mid 2010s. However, despite creating thresholds, the CDC cautions no safe level of lead has ever been identified.22 Lanphear commented on the necessity to remove lead contamination completely, saying:23

“Our study calls into question the assumption that specific toxicants, like lead, have ‘safe levels.’ [Rather it] suggests that low-level environmental lead exposure is a leading risk factor for premature death in the USA, particularly from cardiovascular disease.”

The issue of preventing lead poisoning is a pressing matter, whether you have young children in your home or not. Adults are also adversely affected by lead contamination, including neurological dysfunction and cardiovascular damage. Harvard Medical School offers the following suggestions to protect yourself and your family against lead exposure:24

  • Was your home built before 1978? If so, get it inspected to determine whether it has any lead paint
  • Lead paint removal should be done by a certified professional to ensure safety. The dust is highly toxic. For more information on this, see the EPA’s “Lead-Based Paint Activities Professionals” page25
  • Get your water tested for lead
  • Be mindful of the fact certain household objects may also contain lead. For information about lead-containing products and recalls, see the Consumer Products Safety Commission’s website26
  • Get your child and yourself tested for lead. Ideally, all children should be tested at ages 1 and 2, and again at ages 3 and 4 if you live in an older home. It’s also recommended to test your child’s level whenever there’s concern about exposure. A level of 5 mcg/dL or higher is considered dangerous
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