Car tires and brake pads produce harmful microplastics

These particles can end up in bodies of freshwater and, eventually, the ocean

TREAD LIGHTLY Tiny pieces from rubber tires, brake pads and asphalt make up most of the airborne microplastic pollution around three German highways, a study finds.

TREAD LIGHTLY Tiny pieces from rubber tires, brake pads and asphalt make up most of the airborne microplastic pollution around three German highways, a study finds.

There’s a big problem where the rubber meets the road: microplastics.

Scientists analyzed more than 500 small particles pulled from the air around three busy German highways, and found that the vast majority — 89 percent — came from vehicle tires, brake systems and roads themselves. All together, these particles are classified by the researchers as microplastics, though they include materials other than plastic.

Those particles get blown by wind and washed by rain into waterways that lead to the ocean, where the debris can harm aquatic animals and fragile ecosystems, says environmental scientist Reto Gieré of the University of Pennsylvania. He presented the findings on November 6 at the annual meeting of the Geological Society of America in Indianapolis. Previous research has estimated that about 30 percent of the volume of microplastics polluting oceans, lakes and rivers come from tire wear.

“We all want to reduce CO2 emissions” from vehicle exhaust, Gieré says. “But you can’t stop tire abrasion.” Traffic congestion makes the problem worse. Vehicles traveling at constant speeds, without so much brake use, produced fewer particles, the researchers found.

Because some materials, including synthetic rubber, become coated in dust and other tinier bits of debris, they’re not always easy to identify. The researchers figured out what each particle was by examining each of them under a scanning electron microscope and running chemical analyses.

“These [tire] particles are stealthy,” says John Weinstein, an environmental toxicologist at the Citadel in Charleston, S.C., who was not involved in the study.

Engineers are plugging holes in drinking water treatment | Access to clean water still isn’t universal

New tech solutions

These three new water-cleaning approaches wouldn’t require costly infrastructure overhauls.

Ferrate to cover many bases

Reckhow’s team at UMass Amherst is testing ferrate, an ion of iron, as a replacement for several water treatment steps. First, ferrate kills bacteria in the water. Next, it breaks down carbon-based chemical contaminants into smaller, less harmful molecules. Finally, it makes ions like manganese less soluble in water so they are easier to filter out, Reckhow and colleagues reported in 2016 in Journal–American Water Association. With its multifaceted effects, ferrate could potentially streamline the drinking water treatment process or reduce the use of chemicals, such as chlorine, that can yield dangerous by-products, says Joseph Goodwill, an environmental engineer at the University of Rhode Island in Kingston.

Ferrate could be a useful disinfectant for smaller drinking water systems that don’t have the infrastructure, expertise or money to implement something like ozone treatment, an approach that uses ozone gas to break down contaminants, Reckhow says.

Early next year, in the maiden voyage of his mobile water treatment lab, Reckhow plans to test the ferrate approach in the small Massachusetts town of Gloucester.

In the 36-foot trailer is a squeaky-clean array of plastic pipes and holding tanks. The setup routes incoming water through the same series of steps — purifying, filtering and disinfecting — that one would find in a standard drinking water treatment plant. With two sets of everything, scientists can run side-by-side experiments, comparing a new technology’s performance against the standard approach. That way researchers can see whether a new technology works better than existing options, says Patrick Wittbold, the UMass Amherst research engineer who headed up the trailer’s design.

NICE WHEELS Patrick Wittbold, UMass Amherst quality assurance manager, helped design the Mobile Water Innovation Laboratory (left), a trailer that will test new drinking water technologies around Massachusetts. Inside the van is a flexible setup of filters, pipes and chemicals (right).

NICE WHEELS Patrick Wittbold, UMass Amherst quality assurance manager, helped design the Mobile Water Innovation Laboratory (left), a trailer that will test new drinking water technologies around Massachusetts. Inside the van is a flexible setup of filters, pipes and chemicals (right).

Charged membranes

Filtering membranes tend to get clogged with small particles. “That’s been the Achilles’ heel of membrane treatment,” says Brian Chaplin, an engineer at the University of Illinois at Chicago. Unclogging the filter wastes energy and increases costs. Electricity might solve that problem and offer some side benefits, Chaplin suggests.

His team tested an electrochemical membrane made of titanium oxide or titanium dioxide that both filters water and acts as an electrode. Chemical reactions happening on the electrically charged membranes can turn nitrates into nitrogen gas or split water molecules, generating reactive ions that can oxidize contaminants in the water. The reactions also prevent particles from sticking to the membrane. Large carbon-based molecules like benzene become smaller and less harmful.

In lab tests, the membranes effectively filtered and destroyed contaminants, Chaplin says. In one test, a membrane transformed 67 percent of the nitrates in a solution into other molecules. The finished water was below the EPA’s regulatory nitrate limit of 10 parts per million, he and colleagues reported in July in Environmental Science and Technology. Chaplin expects to move the membrane into pilot tests within the next two years.

Obliterate the PFAS

The industrial chemicals known as PFAS present two challenges. Only the larger ones are effectively removed by granular activated carbon, the active material in many household water filters. The smaller PFAS remain in the water, says Christopher Higgins, an environmental engineer at the Colorado School of Mines in Golden. Plus, filtering isn’t enough because the chunky chemicals are hard to break down for safe disposal.

Higgins and colleague Timothy Strathmann, also at the Colorado School of Mines, are working on a process to destroy PFAS. First, a specialized filter with tiny holes grabs the molecules out of the water. Then, sulfite is added to the concentrated mixture of contaminants. When hit with ultraviolet light, the sulfite generates reactive electrons that break down the tough carbon-fluorine bonds in the PFAS molecules. Within 30 minutes, the combination of UV radiation and sulfites almost completely destroyed one type of PFAS, other researchers reported in 2016 in Environmental Science and Technology.

Soon, Higgins and Strathmann will test the process at Peterson Air Force Base in Colorado, one of nearly 200 U.S. sites known to have groundwater contaminated by PFAS. Cleaning up those sites would remove the pollutants from groundwater that may also feed wells or city water systems.

Filter and destroy

An electrochemical membrane filters out contaminants like a traditional membrane. As a bonus, it also breaks down contaminants via chemical reactions on the membrane’s surface.

water membrane

Engineers are plugging holes in drinking water treatment

DRINKABILITY  Researchers are testing new ways to bring affordable water treatment to smaller towns and to people who rely on wells.

DRINKABILITY Researchers are testing new ways to bring affordable water treatment to smaller towns and to people who rely on wells.

Off a gravel road at the edge of a college campus — next door to the town’s holding pen for stray dogs — is a busy test site for the newest technologies in drinking water treatment.

In the large shed-turned-laboratory, University of Massachusetts Amherst engineer David Reckhow has started a movement. More people want to use his lab to test new water treatment technologies than the building has space for.

The lab is a revitalization success story. In the 1970s, when the Clean Water Act put new restrictions on water pollution, the diminutive grey building in Amherst, Mass. was a place to test those pollution-control measures. But funding was fickle, and over the years, the building fell into disrepair. In 2015, Reckhow brought the site back to life. He and a team of researchers cleaned out the junk, whacked the weeds that engulfed the building and installed hundreds of thousands of dollars worth of monitoring equipment, much of it donated or bought secondhand.

“We recognized that there’s a lot of need for drinking water technology,” Reckhow says.  Researchers, students and start-up companies all want access to test ways to disinfect drinking water, filter out contaminants or detect water-quality slipups. On a Monday afternoon in October, the lab is busy. Students crunch data around a big table in the main room. Small-scale tests of technology that uses electrochemistry to clean water chug along, hooked up to monitors that track water quality. On a lab bench sits a graduate student’s low-cost replica of an expensive piece of monitoring equipment. The device alerts water treatment plants when the by-products of disinfection chemicals in a water supply are reaching dangerous levels. In an attached garage, two startup companies are running larger-scale tests of new kinds of membranes that filter out contaminants.

BACK TO LIFE David Reckhow and his colleagues at UMass Amherst have renovated an old building into a new lab to test the latest drinking water treatment technology.

BACK TO LIFE David Reckhow and his colleagues at UMass Amherst have renovated an old building into a new lab to test the latest drinking water treatment technology.

Parked behind the shed is the almost-ready-to-roll newcomer. Starting in 2019, the Mobile Water Innovation Laboratory will take promising new and affordable technologies to local communities for testing. That’s important, says Reckhow, because there’s so much variety in the quality of water that comes into drinking water treatment plants. On-site testing is the only way to know whether a new approach is effective, he says, especially for newer technologies without long-term track records.

The facility’s popularity reflects a persistent concern in the United States: how to ensure affordable access to clean, safe drinking water. Although U.S. drinking water is heavily regulated and pretty clean overall, recent high-profile contamination cases, such as the 2014 lead crisis in Flint, Mich. (SN: 3/19/16, p. 8), have exposed weaknesses in the system and shaken people’s trust in their tap water.

Tapped out

In 2013 and 2014, 42 drinking water–associated outbreaks resulted in more than 1,000 illnesses and 13 deaths, based on reports to the U.S. Centers for Disease Control and Prevention. The top culprits were Legionella bacteria and some form of chemical, toxin or parasite, according to data published in November 2017.

Those numbers tell only part of the story, however. Many of the contaminants that the U.S. Environmental Protection Agency regulates through the 1974 Safe Drinking Water Act cause problems only when exposure happens over time; the effects of contaminants like lead don’t appear immediately after exposure. Records of EPA rule violations note that in 2015, 21 million people were served by drinking water systems that didn’t meet standards, researchers reported in a February study in the Proceedings of the National Academy of Sciences. That report tracked trends in drinking water violations from 1982 to 2015.

New rules boost violations

The Safe Drinking Water Act regulates levels of contaminants in public water supplies. This graph tracks violations of the act over time. Spikes in violations often coincide with new, more stringent rules.



Current technology can remove most contaminants, says David Sedlak, an environmental engineer at the University of California, Berkeley. Those include microbes, arsenic, nitrates and lead. “And then there are some that are very difficult to degrade or transform,” such as industrial chemicals called PFAS.

Smaller communities, especially, can’t always afford top-of-the-line equipment or infrastructure overhauls to, for example, replace lead pipes. So Reckhow’s facility is testing approaches to help communities address water-quality issues in affordable ways.

Some researchers are adding technologies to deal with new, potentially harmful contaminants. Others are designing approaches that work with existing water infrastructure or clean up contaminants at their source.

How is your water treated?

A typical drinking water treatment plant sends water through a series of steps.

First, coagulants are added to the water. These chemicals clump together sediments, which can cloud water or make it taste funny, so they are bigger and easier to remove. A gentle shaking or spinning of the water, called flocculation, helps those clumps form (1). Next, the water flows into big tanks to sit for a while so the sediments can fall to the bottom (2). The cleaner water then moves through membranes that filter out smaller contaminants (3). Disinfection, via chemicals or ultraviolet light, kills harmful bacteria and viruses (4). Then the water is ready for distribution (5).

There’s a lot of room for variation within that basic water treatment process. Chemicals added at different stages can trigger reactions that break down chunky, toxic organic molecules into less harmful bits. Ion-exchange systems that separate contaminants by their electric charge can remove ions like magnesium or calcium that make water “hard,” as well as heavy metals, such as lead and arsenic, and nitrates from fertilizer runoff. Cities mix and match these strategies, adjusting chemicals and prioritizing treatment components, based on the precise chemical qualities of the local water supply.

Some water utilities are streamlining the treatment process by installing technologies like reverse osmosis, which removes nearly everything from the water by forcing the water molecules through a selectively permeable membrane with extremely tiny holes. Reverse osmosis can replace a number of steps in the water treatment process or reduce the number of chemicals added to water. But it’s expensive to install and operate, keeping it out of reach for many cities.

Fourteen percent of U.S. residents get water from wells and other private sources that aren’t regulated by the Safe Drinking Water Act. These people face the same contamination challenges as municipal water systems, but without the regulatory oversight, community support or funding.

“When it comes to lead in private wells … you’re on your own. Nobody is going to help you,” says Marc Edwards, the Virginia Tech engineer who helped uncover the Flint water crisis. Edwards and Virginia Tech colleague Kelsey Pieper collected water-quality data from over 2,000 wells across Virginia in 2012 and 2013. Some were fine, but others had lead levels of more than 100 parts per billion. When levels are higher than its 15 ppb threshold, the EPA mandates that cities take steps to control corrosion and notify the public about the contamination. The researchers reported those findings in 2015 in the Journal of Water and Health.

To remove lead and other contaminants, well users often rely on point-of-use treatments. A filter on the tap removes most, but not all, contaminants. Some people spring for costly reverse osmosis systems.

Contaminants to keep out of the tap

Microbes: Untreated water can host harmful bacteria and viruses.

By-products of disinfection: Disinfectants such as chlorine and bromine can clear water of dangerous microbes. But these chemicals can react with other molecules to form dangerous by-products such as toxic chloroform.

Industrial chemicals: Per- and polyfluoroalkyl substances, or PFAS, widely used to make nonstick coatings and firefighting foams, are a large group of industrial chemicals that are hard to remove from drinking water and hard to track.

Arsenic: Arsenic is a concern for the 14 percent of U.S. residents who draw their drinking water from private wells instead of public water systems. Arsenic occurs naturally, but can also get into groundwatervia agriculture or mining.

Nitrates: Nitrates enter water supplies largely through runoff from farms and fertilized lawns. In excess, the chemicals can prevent red blood cells from carrying oxygen through the body.

Lead: The EPA mandates that cities adjust water chemistry to minimize the amount of lead that leaches from pipes into tap water, but those corrosion-controlling measures are not foolproof.

Half a degree stole the climate spotlight in 2018


Climate change intensified Hurricane Florence’s rains, which caused the Waccamaw River in South Carolina to overflow.

The grim reality of climate change grabbed center stage in 2018.
This is the year we learned that the 2015 Paris Agreement on global warming won’t be enough to forestall significant impacts of climate change. And a new field of research explicitly attributed some extreme weather events to human-caused climate change. This one-two punch made it clear that climate change isn’t just something to worry about in the coming decades. It’s already here.

This looming problem was apparent three years ago when nearly all of the world’s nations agreed to cut greenhouse gas emissions to limit global warming to no more than 2 degrees Celsius over preindustrial times by 2100 (SN: 1/9/16, p. 6). That pact was hard-won, but even then, some scientists sounded a note of caution: That target wouldn’t be stringent enough to prevent major changes.

So the United Nations took an unprecedented step. It commissioned the Intergovernmental Panel on Climate Change to examine how the world might fare if global warming were limited to 1.5 degrees instead of 2 degrees. That report, released in October, confirmed that half a degree can indeed make a world of difference (SN: 10/27/18, p. 7). A half degree less warming means less sea level rise, fewer species lost due to vanished habitats and fewer life-threatening heat, drought and precipitation extremes (SN: 6/9/18, p. 6).

There’s little time to reverse course. The IPCC report notes that the planet’s average temperature has already increased by nearly 1 degree since preindustrial times, and that rise is contributing to extinctions, lower crop yields and more frequent wildfires. At the end of 2017, three attribution studies for the first time determined that certain extreme events, including an extended marine heat wave in the Pacific Ocean known as “the Blob,” would not have happened without human-induced climate change (SN: 1/20/18, p. 6).

Less is more

Capping global warming at 1.5 degrees Celsius above preindustrial levels rather than 2 degrees can soften climate impacts.

Impact 1.5 degrees 2 degrees
Global average sea level rise by 2100




Increase in ocean acidity by 2100



Probability of an ice-free Arctic Ocean in the summer for any given year



Increase in the annual maximum daily temperature




Proportion of global population facing at least one severe heat wave every five years



Global population exposed to severe drought




Global population exposed to flooding in coastal areas by 2095


million per year


million per year
Proportion of species losing >50% of range that has a climate they can tolerate









Source: IPCC 2018

This year, researchers reported that the 2017 Atlantic hurricane season got a boost from warm waters in the tropical Atlantic, fueled by climate change (SN Online: 9/28/18). And a team of scientists determined that climate change was the engine behind September’s intense rainfall from Hurricane Florence in the Mid-Atlantic region of the United States (SN Online: 9/13/18).

A report released November 23 by hundreds of U.S. climate scientists from 13 federal agencies put a price tag on many of the effects for the United States (SN Online: 11/28/18). The report predicts the country’s economy will shrink by as much as 10 percent by 2100 if global warming continues on its current trajectory.

Climate simulations suggest that Earth will reach the 1.5 degree threshold within a decade. And even if countries were to agree to limit warming to that level, the planet would almost certainly surpass it before the warming reversed, due to the realities of how quickly emissions can be reduced. Passing that target will probably lead to some irreversible changes, such as melted glaciers and species losses. To overshoot the mark by only a small amount, or not at all, requires reducing emissions by about 45 percent relative to 2010 levels by the year 2030. The planet would then be able to reach net zero, when the amount of carbon released to the atmosphere is balanced by the amount removed, by around 2050, the IPCC report notes.

To bring warming back down below the 1.5 degree target by the end of the century, the world will need negative emissions technologies to remove large amounts of carbon dioxide from the atmosphere. Such technologies that limit or even reverse warming are less pie-in-the-sky than they sound, says Stephen Pacala, an ecologist at Princeton University. “Although there is a lot of doom and gloom available on the progress of humanity, there isn’t on the technological side.” Pacala chaired a National Academies of Sciences, Engineering and Medicine committee that released a report in October that analyzed the viability of current and emerging negative emissions technologies as well as encouraged large-scale investments in them.

Some simple negative emissions practices already in use include planting forests to soak up atmospheric carbon, or growing plants for biofuels and then storing underground the CO2 from the burning of those fuels. But current efforts have drawbacks. Planting sufficient forests or biofuel crops “would have a large land footprint,” says economist and IPCC coauthor Sabine Fuss of the Mercator Research Institute on Global Commons and Climate Change in Berlin. And that could impact future food availability and biodiversity.

alternatives to fossil fuels.

To limit global warming, communities need to embrace alternatives to fossil fuels. In Iceland, Reykjavik Energy has a pilot project to directly capture carbon dioxide from the air at a geothermal power plant (shown).

Other negative emissions technologies in development could become game changers, Pacala says. Direct air capture, in which CO2 is removed directly from the atmosphere and converted into synthetic fuel, is a proven technology. But so far, the high cost of direct air capture remains a barrier to commercial-scale development. The National Academies report says that nations should subsidize start-ups to drive competition in this area — after all, that’s what worked for wind and solar power, Pacala notes. Other proposed negative emissions technologies, such as converting atmospheric CO2 into a stable mineral form (SN: 9/15/18, p. 9), show some promise but require large-scale financial investment in their basic science to make them viable, the report states.

Reducing demand for resource-intensive products will also be important to reach the 1.5 degree target, Fuss says. Cities need to move away from fossil fuels, and individuals can do their part by, for example, traveling less (SN: 6/9/18, p. 5), eating less meat (SN: 7/7/18, p. 10) and installing more energy-efficient appliances. Data show that, given the right incentives, people are willing to make such lifestyle changes, says IPCC report coauthor Linda Steg, an environmental psychologist at the University of Groningen in the Netherlands. And those incentives aren’t necessarily financial or based on self-interest, she adds. “People are also motivated by protecting the interests of others, or by the quality of the environment.”

Holding warming to 1.5 degrees “is not impossible,” says Natalie Mahowald, a climate scientist at Cornell University and an IPCC report coauthor. But “it really requires ambitious efforts, and the sooner the better. We have to start cutting emissions now.”

Political will to act varies country by country, but scientists have done what they can to convey the urgency and the scope of the climate change problem, says IPCC report coauthor Heleen de Coninck, an environmental scientist at Radboud University in Nijmegen, Netherlands. Nations “have it in their hands, and they know what they are working with,” de Coninck says. “Now it’s up to them.”

The Paris Accord Promised a Climate Solution. Here’s Where We Are Now.

Delegates at the United Nations climate change conference in Katowice, Poland, last week.

Delegates at the United Nations climate change conference in Katowice, Poland, last week.

World leaders struck an agreement three years ago in Paris to avert the worst effects of climate change, accepting not only that greenhouse gases were dangerously heating the planet, but also that every single country needed to do its part to curtail emissions.

Now, emissions are rising in the United States and China, the world’s two largest economies. Other countries are backsliding on their commitments. The world as a whole is not meeting its targets under the Paris pact. As diplomats meet in Katowice, Poland, this week to bring the deal into effect, the world’s 7.6 billion people face mounting risks from more severe and more frequent floods, droughts and wildfires.

The Paris Agreement, it seems, is only as good as the willingness of national leaders to keep their word.

“We have the ways,” António Guterres, the United Nations secretary general, said this week in Katowice. “What we need is the political will to move forward.”

Champions of the accord point out that the diplomatic process is alive and well and that all of the world’s 195 countries are still in the deal, including the United States, which can exit only at the end of 2020. The science is sharper than before on the dangers of unchecked emissions, and a great many countries, including the poorest, are pushing for more ambitious targets.

The Katowice talks are facing a Saturday deadline, and Mr. Guterres has visited twice to push diplomats to bridge their still-large differences on the details of a “rule book” that will allow countries to implement the Paris Agreement.

“To waste this opportunity in Katowice would compromise our last best chance to stop runaway climate change,” Mr. Guterres said. “It would not only be immoral, it would be suicidal.”

How did we get here?

Things started to change with the election of Donald J. Trump. Less than six months after taking office, he announced the United States would withdraw from the Paris Agreement. At home, his administration has pushed to overturn pollution regulations, making it far less likely that the United States will meet its Paris pledge to cut emissions sharply by 2025.

In August, an effort in Australia to transition away from coal, the dirtiest fossil fuel, resulted in the ouster of the prime minister. The man who succeeded him, Scott Morrison, endeared himself to the industry by bringing a lump of coal into Parliament.

In November, Brazilians elected Jair Bolsonaro, who had pledged to promote agribusiness interests in the Amazon forest, the world’s largest carbon sink.

In Poland, the host country of the latest United Nations talks, the right-wing president, Andrzej Duda, opened the negotiations by saying flatly that his country did not intend to abandon coal.

Other leaders face their own domestic difficulties. Emissions in China have grown for the past two years, signaling the difficulties of shifting the country away from its coal-dependent industrial economyGermany is having a hard time moving away from lignite because of political opposition in the country’s coal-rich east. The French president, Emmanuel Macron, faces unrest at home over layer cake of taxes that working-class people say burdens them unfairly.

All the while, the science has become clearer. A United States government report issued last month concluded that if significant steps were not taken to rein in global warming, it would put a huge dent in the American economy by century’s end.

And an exhaustive report issued weeks before by the Intergovernmental Panel on Climate Change, compiled by hundreds of scientists from around the world convened by the United Nations, said emissions would have to decline significantly by 2030 for the world to avoid a world of worsening food shortages and wildfires.

“The I.P.C.C. has sounded many alarms, and the world just keeps smashing the alarm and keeps on sleeping,” said Hans Joachim Schellnhuber, founder of the Potsdam Institute for Climate Impact Research, on the sidelines of the talks in Katowice.

The world as a whole is not on track to meet the broad goal it set for itself in Paris: to keep the increase in global temperatures “well below” 2 degrees Celsius, or 3.6 degrees Fahrenheit, over preindustrial levels. Under the agreement, each country put forward a voluntary pledge to curtail its own emissions.

So far, those voluntary pledges have not been sufficient. New data made public in Poland this week by the group Climate Action Tracker estimated that current climate policies put the world on pace for somewhere around 3.3 degrees Celsius.

“If we are serious about the Paris Agreement, we need to see different numbers,” Petteri Taalas, head of the World Meteorological Organization, told the delegates in Katowice this week. He noted that global emissions had risen in 2018.

The negotiations in Katowice are aimed at setting out the rules by which countries will regularly update their emissions-reductions pledges and assess one another’s progress. But even those technical discussions about the rule book have been bogged down by intense political differences.

“We are in a planetary emergency and the longer we waste time in the negotiating room not acknowledging this fact, we do so at the cost of our people and our communities,” a statement from a bloc of poor countries, led by Ethiopia, urged on Thursday.

For its part, even though the United States has said it intends to withdraw from the Paris deal, the country has still sent a delegation to the negotiations. “These global energy and environmental policies will have an impact on U.S. interests, and we want to make sure we protect those so they’re not hamstringing economic growth, innovation, entrepreneurship in the U.S.,” said Wells Griffith, Mr. Trump’s international energy and climate adviser.

The Trump administration pointedly refused to embrace the United Nations’ scientific report, siding with three other major oil- and gas-producing countries — Russia, Saudi Arabia and Kuwait — to block a resolution in Poland to “welcome” the report.

An installation promoting coal at the conference.CreditKarolina Jonderko for The New York Times

An installation promoting coal at the conference.CreditKarolina Jonderko for The New York Times

To be sure, the Paris pact, and the growing scientific clarity about global warming, has spurred countries and businesses to reorient themselves. From shipping to fast food to insurance, companies are setting their own targets to reduce carbon footprints. Solar and wind energy is expanding rapidly. Within the United States, a number of cities and states have dissented from the Trump administration’s planned exit and created their own local plans to green their economies.

Christiana Figueres, the former United Nations climate chief who led the Paris negotiations to their conclusion in December 2015, argued that the pact had set into motion a fundamental transformation of the global economy away from fossil fuels. It would be naïve, she said, to not expect pushback.

“Not to fall into Pollyanna land here, one has to recognize that of course there are huge, huge very powerful, very well endowed vested forces that are very threatened by this,” Ms. Figueres said in a podcast streamed on her website. “Let’s not get paralyzed by that,” she said.

Organic food worse for the climate

The crops per hectare are significantly lower in organic farming, which, according to the study, leads to much greater indirect carbon dioxide emissions from deforestation. Credit: Yen Strandqvist/Chalmers University of Technology

The crops per hectare are significantly lower in organic farming, which, according to the study, leads to much greater indirect carbon dioxide emissions from deforestation. Credit: Yen Strandqvist/Chalmers University of Technology

Organically farmed food has a bigger climate impact than conventionally farmed food, due to the greater areas of land required. This is the finding of a new international study involving Chalmers University of Technology, Sweden, published in the journal Nature.

The researchers developed a new method for assessing the climate impact from land-use, and used this, along with other methods, to compare organic and conventional food production. The results show that organic food can result in much greater emissions.

“Our study shows that organic peas, farmed in Sweden, have around a 50 percent bigger climate impact than conventionally farmed peas. For some foodstuffs, there is an even bigger difference – for example, with organic Swedish winter wheat the difference is closer to 70 percent,” says Stefan Wirsenius, an associate professor from Chalmers, and one of those responsible for the study.

The reason why organic food is so much worse for the climate is that the yields per hectare are much lower, primarily because fertilisers are not used. To produce the same amount of organic food, you therefore need a much bigger area of land.

The ground-breaking aspect of the new study is the conclusion that this difference in land usage results in organic food causing a much larger climate impact.

“The greater land-use in organic farming leads indirectly to higher carbon dioxide emissions, thanks to deforestation,” explains Stefan Wirsenius. “The world’s food production is governed by international trade, so how we farm in Sweden influences deforestation in the tropics. If we use more land for the same amount of food, we contribute indirectly to bigger deforestation elsewhere in the world.”

Even organic meat and dairy products are – from a climate point of view – worse than their conventionally produced equivalents, claims Stefan Wirsenius.

“Because organic meat and milk production uses organic feeds, it also requires more land than conventional production. This means that the findings on organic wheat and peas in principle also apply to meat and milk products. We have not done any specific calculations on meat and milk, however, and have no concrete examples of this in the article,” he explains.

A new metric: Carbon Opportunity Cost
The researchers used a new metric, which they call “Carbon Opportunity Cost”, to evaluate the effect of greater land-use contributing to higher carbon dioxide emissions from deforestation. This metric takes into account the amount of carbon that is stored in forests, and thus released as carbon dioxide as an effect of deforestation. The study is among the first in the world to make use of this metric.

“The fact that more land use leads to greater climate impact has not often been taken into account in earlier comparisons between organic and conventional food,” says Stefan Wirsenius. “This is a big oversight, because, as our study shows, this effect can be many times bigger than the greenhouse gas effects, which are normally included. It is also serious because today in Sweden, we have political goals to increase production of organic food. If those goals are implemented, the climate influence from Swedish food production will probably increase a lot.”

So why have earlier studies not taken into account land-use and its relationship to carbon dioxide emissions?

“There are surely many reasons. An important explanation, I think, is simply an earlier lack of good, easily applicable methods for measuring the effect. Our new method of measurement allows us to make broad environmental comparisons, with relative ease,” says Stefan Wirsenius.

The results of the study are published in the article “Assessing the efficiency of changes in land use for mitigating climate change” in the journal Nature. The article is written by Timothy Searchinger, Princeton University, Stefan Wirsenius, Chalmers University of Technology, Tim Beringer, Humboldt Universität zu Berlin, and Patrice Dumas, Cired.

She trolled Trump, but can she lead a green wave across Europe?

In February last year, a week after Donald Trump had signed an anti-abortion executive order surrounded by seven men, Isabella Lövin posted a photograph of herself on Twitter signing a climate change bill alongside seven other women.

Former deputy PM Isabella Lövin and fellow Green Gustav Fridolin on their way to the People’s Climate March in Stockholm in September

Former deputy PM Isabella Lövin and fellow Green Gustav Fridolin on their way to the People’s Climate March in Stockholm in September

Sweden’s then deputy prime minister remained enigmatic as the picture went viral and she was asked whether she had been “trolling” the US president. “It is up to the observer to interpret the photo,” she was quoted as saying. “We are a feminist government, which shows in this photo.”

The image made headlines around the world and, nearly two years on, is still what Lövin is best known for internationally. But the Swedish Green party leader and minister for international development is no mere social media politician. During her party’s historic first period in government she relentlessly pushed through an exhausting list of more than 50 policies, including a flight tax, the so-called Swedish Proposal, which tripled the price of EU emissions credits, and the carbon law she was signing in the picture that went viral.


Lövin is one of the leading figures in what she says is a resurgence in environmentally conscious politics across the continent. “There is a green wave going on in Europe, in Germany, Luxembourg and Belgium, and in Finland as well,” she says. “I’m convinced that green parties offer a positive vision, and also the willingness to take on the huge challenges that we see in the world right now.”

The slogan on her Twitter profile, “The climate can’t wait”, sums up the Lövin approach.

“We’ve been very focused on results, and many of these issues have beenfundamental, long-term policies,” she says, sitting in her office in Sweden’s foreign ministry.

Isabella Lovin, left, then the deputy PM, with female colleagues signing a climate change bill

Isabella Lovin, left, then the deputy PM, with female colleagues signing a climate change bill

“To work seriously on changing policies and setting long-term targets, and forming majorities and doing agreements with other parties, those things don’t pay off very easily in PR strategies.”

It’s the same single-mindedness she as shown ever since bursting into public life 10 years ago following the 2007 publication of Silent Seas – The Fish Race to the Bottom, a rigorously researched, dramatic exposé of the crisis in global fisheries.

“It totally changed my life,” she says of the book, published when she was 44. “But what really changed my life was the decision to write the book. I felt such a huge anxiety and anger about what we’re doing to our planet, and specifically when I understood the issue of overfishing – because we’re actually destroying our oceans with our eyes open.” I decided … I will try to write about this topic, and then at least I’ve tried’.”

The book was a sensation, winning Sweden’s two main journalism prizes, and launching a process which saw Lövin sent to Brussels as an MEP by the Green party with a single mission: to push through reform of fisheries policies. When I ask if she succeeded, she laughs. “Quite modestly I have to say ‘yes’. I was there for five years and we managed to get a majority in the European parliament to ban shark finning, overfishing and discarding fish, and to bring in a new common fisheries policy that sets the target that we must have sustainable fish stocks by 2020.”

There’s a section in the book when she considers rescuing a dogfish, still alive at a fish auction, and releasing it into the sea. But she bristles when I ask if she sees herself as an eco-warrior. “No, no, no. Never. For me, it was extremely important to really do the research and see the facts,” she says.

“I see the environmental challenges that we have now, they are existential. It’s that serious. It’s not just being like an image, that you’re an eco-warrior or whatever. This is really happening now.”

That is why, when the Swedish Green party formed a coalition with the Social Democrats in 2014, Lövin took the next step and joined the national government, first as minister for international development cooperation, then, when her colleague Åsa Romson resigned, as deputy prime minister and climate minister. “It was tough for me personally,” she says. “But I felt if I don’t do this, I might regret for the rest of my life I didn’t try to do something about the problems I saw.”

Government has also been a bruising experience for the party, particularly at the end of 2015 and the start of 2016, when a dramatic tightening of immigration policy was followed by a failure to stop Vattenfall, the state power company,selling, rather than shutting down, its German coal mines. “One of the mistakes we made … was maybe to say that we would succeed in certain issues where it wasn’t possible, and that has haunted us,” she says, of the coal debacle.

As a result, the party lost roughly half of its 20,000 members, and then, in September’s election, a third of its seats. The party says, however, it always knew that power would come at a heavy price, and had aimed only to stay above the 4% threshold needed to keep its place in parliament.

“It’s been a long-term strategy for the Swedish Greens to come into government and really take responsibility,” says Lövin. “We managed to do that and not be destroyed in the process.”

The Greens may yet have a role in the future Swedish government. Coalition talks have failed to lead anywhere and, last week, Annie Lööf, the leader of the minority Centre party, failed to form a government, the second such doomed attempt. Lövin believes her party is now in a strong position and could find a place in coalitions dominated by the centre-right Alliance bloc or the Social Democrats, whose leader, Stefan Löfven, was on Friday announced as the next person to be put forward to parliament as prime minister.

“It’s difficult to exclude any possibility at this point,” she says. “The Green party has been mentioned now as a very interesting partner for the more liberal rightwing parties, and of course we’re also included in what most people think would be a Social Democratic or more centre government.”

While some other party leaders have spent the last two months locked in coalition talks, Lövin has instead been busy serving as a minister in the transitional government, leading preparations for next month’s Katowice Climate Change Conference.

“I hope to be there,” she says. “I’m very concerned, actually, because with the Paris Agreement, everyone was very happy that we got to get an agreement, but now the logic of the climate negotiations is back to where it was before Paris, with the poor counties, including China and India, blaming the richer countries for what’s happening.”

Lövin’s press secretary then chips in to warn her that it’s time for her next appointment, but she has one more thing she wants to say. “I think one of the most important things for all democracies around the world to contemplate is how we are going to develop and protect democracy when voters are so impatient and learn their news from social media, which can be very biased.”

A viral tweet such as hers may get through to hundreds of thousands of people with a simple message about how wrong it is for a White House full of men to sign orders that affect women’s bodies and lives. It cannot, however, communicate more complicated, nuanced information.

“The understanding of long processes, which is, very necessary if you are going to have a democracy, not a dictatorship, is very low,” she says.

“I think just staying on very superficial messages and going with a populist movement is totally the opposite of what a green party should be.”

Purple photosynthetic bacteria ‘batteries’ turn sewage into clean energy

You’ve flushed something valuable down the toilet today.

Organic compounds in household sewage and industrial wastewater are a rich potential source of energy, bioplastics and even proteins for animal feed — but with no efficient extraction method, treatment plants discard them as contaminants. Now researchers have found an environmentally-friendly and cost-effective solution.

Wastewater treatment plant.

Wastewater treatment plant.

Published in Frontiers in Energy Research, their study is the first to show that purple phototrophic bacteria — which can store energy from light –, when supplied with an electric current, can recover near to 100% of the carbon from any type of organic waste while generating hydrogen gas for electricity production.

“One of the most important problems of current wastewater treatment plants is high carbon emissions,” says co-author Dr Daniel Puyol of King Juan Carlos University, Spain. “Our light-based biorefinery process could provide a means to harvest green energy from wastewater, with zero carbon footprint.”

Purple photosynthetic bacteria

When it comes to photosynthesis, green hogs the limelight. But as chlorophyll retreats from autumn foliage, it leaves behind its yellow, orange and red cousins. In fact, photosynthetic pigments come in all sorts of colors — and all sorts of organisms.

Cue purple phototrophic bacteria. They capture energy from sunlight using a variety of pigments, which turn them shades of orange, red or brown — as well as purple. But it is the versatility of their metabolism, not their color, which makes them so interesting to scientists.

Purple photosynthetic bacteria

Purple photosynthetic bacteria

“Purple phototrophic bacteria make an ideal tool for resource recovery from organic waste, thanks to their highly diverse metabolism,” explains Puyol.

The bacteria can use organic molecules and nitrogen gas — instead of CO2 and H2O — to provide carbon, electrons, and nitrogen for photosynthesis. This means that they grow faster than alternative phototrophic bacteria and algae, and can generate hydrogen gas, proteins or a type of biodegradable polyester as byproducts of metabolism.

Tuning metabolic output with electricity

Which metabolic product predominates depends on the bacteria’s environmental conditions — like light intensity, temperature, and the types of organics and nutrients available.

“Our group manipulates these conditions to tune the metabolism of purple bacteria to different applications, depending on the organic waste source and market requirements,” says co-author Professor Abraham Esteve-Núñez of University of Alcalá, Spain.

“But what is unique about our approach is the use of an external electric current to optimize the productive output of purple bacteria.”

This concept, known as a “bioelectrochemical system,” works because the diverse metabolic pathways in purple bacteria are connected by a common currency: electrons. For example, a supply of electrons is required for capturing light energy, while turning nitrogen into ammonia releases excess electrons, which must be dissipated. By optimizing electron flow within the bacteria, an electric current — provided via positive and negative electrodes, as in a battery — can delimit these processes and maximize the rate of synthesis.

Maximum biofuel, minimum carbon footprint

In their latest study, the group analyzed the optimum conditions for maximizing hydrogen production by a mixture of purple phototrophic bacteria species. They also tested the effect of a negative current — that is, electrons supplied by metal electrodes in the growth medium — on the metabolic behavior of the bacteria.

Their first key finding was that the nutrient blend that fed the highest rate of hydrogen production also minimized the production of CO2.

“This demonstrates that purple bacteria can be used to recover valuable biofuel from organics typically found in wastewater — malic acid and sodium glutamate — with a low carbon footprint,” reports Esteve-Núñez.

Even more striking were the results using electrodes, which demonstrated for the first time that purple bacteria are capable of using electrons from a negative electrode or “cathode” to capture CO2 via photosynthesis.

“Recordings from our bioelectrochemical system showed a clear interaction between the purple bacteria and the electrodes: negative polarization of the electrode caused a detectable consumption of electrons, associated with a reduction in carbon dioxide production.

“This indicates that the purple bacteria were using electrons from the cathode to capture more carbon from organic compounds via photosynthesis, so less is released as CO2.”

Towards bioelectrochemical systems for hydrogen production

According to the authors, this was the first reported use of mixed cultures of purple bacteria in a bioelectrochemical system — and the first demonstration of any phototroph shifting metabolism due to interaction with a cathode.

Capturing excess CO2 produced by purple bacteria could be useful not only for reducing carbon emissions but also for refining biogas from organic waste for use as fuel.

However, Puyol admits that the group’s true goal lies further ahead.

“One of the original aims of the study was to increase biohydrogen production by donating electrons from the cathode to purple bacteria metabolism. However, it seems that the PPB bacteria prefer to use these electrons for fixing CO2 instead of creating H2.

“We recently obtained funding to pursue this aim with further research and will work on this for the following years. Stay tuned for more metabolic tuning.”

Clean Energy Is Surging, but Not Fast Enough to Solve Global Warming

Wind turbines and solar panels in Hebei Province, China. Renewables are expected to supply 40 percent of the world’s electricity by 2040.

Wind turbines and solar panels in Hebei Province, China. Renewables are expected to supply 40 percent of the world’s electricity by 2040.

Over the next two decades, the world’s energy system will undergo a huge transformation. Wind and solar power are poised to become dominant sources of electricity. China’s once-relentless appetite for coal is set to wane. The amount of oil we use to fuel our cars could peak and decline.

But there’s a catch: The global march toward clean energy still isn’t happening fast enough to avoid dangerous global warming, at least not unless governments put forceful new policy measures in place to reduce carbon dioxide emissions.

That’s the conclusion of the International Energy Agency, which on Monday published its annual World Energy Outlook, a 661-page report that forecasts global energy trends to 2040. These projections are especially difficult right now because the world’s energy markets, which usually evolve gradually, are going through a major upheaval.

Here are some of the report’s major themes:

Around the world, the electricity sector “is experiencing its most dramatic transformation since its creation more than a century ago,” the report said. One big factor is the rapid growth of wind and solar power.

Over the past five years, the average cost of solar power has declined 65 percent and the cost of onshore wind has fallen 15 percent. The energy agency predicts those prices will keep tumbling as technology improves and governments scale back subsidies. Solar plants are becoming well-placed to outcompete new coal plants almost everywhere.

The agency sees renewable power supplying 40 percent of the world’s electricity by 2040, up from 25 percent today. Even that forecast could prove conservative: In the past, the agency has underestimated the speed at which wind and solar power proliferate.

“Our solar expectations are about 20 percent higher than they were last year, both because of new policies in China and India and because the costs are coming down so fast,” said Fatih Birol, the agency’s executive director.

The report warns, however, that many countries will need to retool their grids to manage the output from wind and solar plants, which run intermittently. That will mean overhauling rules for how electricity markets operate, relying on batteries and gas plants for grid flexibility and exploring new tools like hydrogen storage.

For decades, developing countries like China and India have turned to coal as the cheapest, easiest way to power their economies and lift themselves out of poverty. It’s a big reason carbon dioxide emissions have skyrocketed.

That’s quickly changing.

China, which burns half the world’s coal, is making heavy investments in wind, solar, nuclear and natural gas, spurred in part by concerns about air pollution from its coal plants. The agency now projects that China’s coal consumption will plateau around 2025, with renewables overtaking coal as the country’s biggest source of electricity by 2040.

And, while countries in Southeast Asia and elsewhere are still drawing up plans to build new coal plants, the agency expects this frenzy of construction to slow sharply after 2020.

But don’t expect coal to disappear altogether. While the era of rapid coal growth is fading, the agency projects that global coal consumption could stay flat for decades. One reason for that: The average coal plant in Asia is less than 15 years old (compared to about 41 years in the United States). Those plants will keep polluting for decades, unless countries decide to retire them early or develop technology to capture and bury their emissions.

A refinery in Port Arthur, Tex. The petrochemical industry has not seen the same gains in efficiency as the energy sector.

A refinery in Port Arthur, Tex. The petrochemical industry has not seen the same gains in efficiency as the energy sector.

Even as the world puts hundreds of millions of new cars on the road, we’re increasingly using less oil to fuel them. The report projects that global oil use for cars will peak by the mid-2020s as countries ratchet up their fuel-economy standards and deploy more electric vehicles.

That doesn’t mean overall oil use will decline, however. Only about one-quarter of the world’s oil is used to fuel passenger cars. The rest is used to fuel freight trucks, ships, and airplanes; for heating; and to make plastics and other petrochemicals.

Those sectors haven’t seen the same improvements in efficiency. As a result, the agency expects global oil demand to keep rising through 2040, led by developing countries.

Even with the impressive recent gains for renewable energy, the world is still far from solving global warming. Global carbon dioxide emissions rose 1.6 percent last year and are on track to climb again this year. The report projects that emissions will keep rising slowly until 2040.

One reason: Carbon-free sources like wind, solar and nuclear power aren’t yet growing fast enough to keep up with rising global energy demand, particularly in places like India and Southeast Asia. That means fossil fuel use keeps growing to fill the gap.

For this to change, nations will have to enact sweeping new policies, like investing in energy efficiency to slow demand growth, curbing methane leaks from oil and gas operations, and developing carbon capture technology for existing fossil fuel power plants and cement factories.

Governments will play a key role: The report notes that the world invests $2 trillion annually in energy infrastructure, and 70 percent of that is directed by state-owned companies or regulators. “That tells me that our energy destiny will rely heavily on government decisions in the next two decades,” Mr. Birol said.

Air-Conditioners Cool the Home but Heat the Planet. Can Anyone Invent a Better One?

As incomes grow and more people move to cities, and as global temperatures rise, the world is buying more air-conditioners. And as more air-conditioners spin up — you guessed it — they cause more warming, both through the energy they consume and the gases they release.

In fact, the number of air-conditioning units worldwide could surge to 4.5 billion by 2050 from about 1.2 billion today, a new report warns. By the end of the century, household air-conditioning alone could elevate global temperatures by as much as a half-degree Celsius.

household air-conditioning alone could elevate global temperatures by as much as a half-degree Celsius

household air-conditioning alone could elevate global temperatures by as much as a half-degree Celsius

Richard Branson, the British entrepreneur and Virgin Group founder, hopes to break that vicious cycle. This week he helped to initiate the Global Cooling Prize, a $3 million technology competition that aims to spur more efficient air-conditioning technology.

The prize aims to “literally help save to save the world from the disaster it is facing,” Mr. Branson said on a brief call with reporters ahead of the program’s formal opening in New Delhi, India, on Monday. (The Indian government is a partner.)

“Most air-conditioners, at their core, are still running on 100-year-old vapor compression technology,” Mr. Branson said. “There’s been no incentive for innovation.” He added that the prize isn’t open only to start-ups, but people from all walks of life.

The prize initially offers 10 chosen contenders $200,000 to build prototypes of more efficient cooling methods. That technology will then be tested in a lab as well as in 10 Indian apartments in midsummer.

“We think the world needs air-conditioners that are five times more efficient,” said Iain Campbell of the Rocky Mountain Institute, a Colorado-based nonprofit that wrote the new report and is managing the prize.

One start-up, for example — SkyCool Systems, based in Palo Alto, Calif. — is working on a literally out-of-this-world technology that beams the heat of the sun away from the earth and into space. The technology would take advantage of the ability of infrared light to pass through the atmosphere at certain wavelengths.

There are also more down-to-earth ideas. As my colleague Kendra Pierre-Louis wrote this year, experts say governments should also set efficiency standards for air-conditioners and provide incentives for manufacturers and buyers.

There has been some good news. As part of an agreement known as the Kigali amendment to the Montreal Protocol, some countries are working to phase out refrigerants that are also potent greenhouse gases.