EarthTalk® | April 2020

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Travelers at Hartsfield-Jackson Atlanta International Airport wearing facemasks in early March 2020 as the Coronavirus spreads throughout the United States. Credit: Chad Davis, FlickrCC.

Dear EarthTalk: I feel weird asking, but is there an environmental bright side to the spread of the Coronavirus? And is there an environmental cause of the pandemic? — Jane K., Miami, FL

Coronavirus has killed thousands of people and sickened hundreds of thousands (if not millions) more around the world. It has also caused mass hysteria, and public health officials are bracing for the worst.

The situation is mostly bad news, but the “silver lining” for the environment might be a downturn in carbon emissions and other pollution due to reduced manufacturing, people staying home, less air travel, far fewer cars on the road — and generally less overall physical movement and economic activity.

A recent analysis by Carbon Brief, a UK-based website covering news in climate sciences and climate and energy policy, found that measures to contain the Coronavirus in China have resulted in reductions in output of 15 to 40 percent across key industrial sectors there, with an overall reduction in greenhouse gas emissions by some 25 percent below normal over the course of February 2020.

Only time will tell if the situation here gets as dire as in China. “Some data indicate school closures and work-from-home mandates have already reduced traffic flow around Seattle,” reports E&E News. “Similar statistics have suggested that rush-hour traffic is down in New York City, as well.” Meanwhile, BART ridership in and around San Francisco is down 25 percent so far in March as a result of people staying home. These examples don’t add up to a huge downturn in emissions yet, but we’re still in the initial stages of the pandemic’s spread.

For those who would like to see this reduced output continue even after we are over the hump with this outbreak, don’t count on it. We’re all used to the conveniences and creature comforts that a buzzing economic system brings us, and fat chance if the Chinese, Europeans or Americans are going to voluntarily return to a more ascetic lifestyle once the Coronavirus eases its chokehold. To wit, the Chinese government is already hyping a stimulus package designed to make up for the months of lost economic opportunity for businesses there. And we aren’t far behind, with President Trump promising a payroll tax cut, an infrastructure push, paid sick leave for hourly employees and the potential delay of estimated tax payments as ways to stimulate the economy in the wake of the pandemic.

As for whether there’s an environmental “cause” of the pandemic, we don’t think so — except in as much as it probably came to us from wildlife. But according to the World Health Organization, environmental factors that lead to human congregation — such as sunny weather — could theoretically increase the rate of spread. On the other hand, studies suggest that warmer temperatures reduce the spreading of respiratory infections, due to their effects on the dynamics of cough droplet flight. But all in all, the research shows that environmental conditions do little to affect the transmission rates of viruses such as Coronavirus.

Contacts: Analysis: Coronavirus has temporarily reduced China’s CO2 emissions by a quarter, www.carbonbrief.org/analysis-coronavirus-has-temporarily-reduced-chinas-co2-emissions-by-a-quarter; How the Coronavirus Pandemic Is Affecting CO2 Emissions, www.scientificamerican.com/article/how-the-coronavirus-pandemic-is-affecting-co2-emissions/; “Environmental factors influencing the spread of communicable diseases,” www.who.int/environmental_health_emergencies/disease_outbreaks/communicable_diseases/en/.


The SYSAV plant in Malmö is one of 33 waste-to-energy plants in Sweden. Credit: David Castor.
Dear EarthTalk: I’ve heard that Sweden incinerates most of its trash. Why don’t we do more of this in the U.S., given that we’re running out of landfill space? — Oscar Gentry, New Bern, NC

Sweden does burn the vast majority of its trash — only 1 percent of the country’s waste ends up in landfills — and even makes a profit by importing trash from neighboring countries to process in its high-efficiency, low-emission incinerators. And it makes a lot of sense, given the huge toll landfills take on the environment, leaking liquids into surrounding soils and polluting groundwater while sending huge amounts of methane, a potent greenhouse gas, into the atmosphere.

Burning waste in an uncontrolled setting is undeniably terrible for the environment, given the huge load of carbon dioxide, dioxin and volatile organic compounds sent skyward. But in a modern waste incineration facility, excess gases leftover after the trash is burned undergo a thorough filtering and scrubbing process that complies with stringent environmental standards (delineated in the Clean Air Act here in the U.S. and by even stricter rules across the European Union). Furthermore, incinerating trash reduces its volume by 87 percent, which directly translates to an equivalent reduction in the amount of space required for landfills.

At this point, much of the world has adopted waste-to-energy (WTE) technologies, with almost 800 facilities around the world. In the EU, there are about 400 WTE facilities currently in operation. In the U.S., however, there are only 77. This is somewhat surprising, especially given that landfills are America’s third-largest methane emitter. Additionally, America is one of the largest waste producers in the world, both as a nation, and per capita. Why not convert all this waste into energy?

But WTE has faced many stumbling blocks in the U.S. Public stigma against WTE has played a significant role in preventing widespread adoption of this technology here. It seems Americans just can’t accept the idea that burning trash could actually be a good thing for the environment or public health. While this attitude is understandable, it would likely fall apart if more of us knew the facts.

Another issue for WTE in the U.S. is economics. In Europe and other countries, WTE plants receive government funding, and landfilling rates are often higher. In the U.S, it is still often cheaper to landfill waste than to turn it into energy.

However, WTE could still have a future in America. In many areas where landfill rates are expensive, WTE is increasingly looking like a promising solution. If these rates continue to rise, and the government decides to reallocate some of its funding, we might be seeing more WTE plants come online before long.

More data coming in from other countries about the benefits they’re deriving from WTE operations could also accelerate this adoption process. Finally, advances in scrubbing and cleaning technologies will likely reduce the negative impact of incineration even more.

You can help facilitate the transition to WTE by encouraging local officials to consider it as a viable option for expanding waste management capacity, given the shrinking amount of landfill space available to municipalities everywhere and lack of other good options for getting rid of our garbage.

Contacts: “Canada produces the most waste in the world. The U.S. ranks third,” www.usatoday.com/story/money/2019/07/12/canada-united-states-worlds-biggest-producers-of-waste/39534923/; “Ethiopia has an innovative power plant that turns waste to energy,” youtube.com/watch?v=K2SBjf1O0HU.


Some environmentalists are opting to meet their dietary protein needs by eating bugs—like this Thai green curry crickets dish—instead of meat. Credit: Flavio Ensiki, FlickrCC.
Dear EarthTalk: Is switching out meat for edible bugs to satisfy our protein needs a viable way to ratchet down our carbon emissions and overall environmental impact? — J. Cruz., Gary, IN

It’s true that humans’ affinity for meat — especially beef, lamb, pork and to a lesser extent chicken — takes a huge toll on the environment given the resources and emissions expended to rear and then transport it to market. In fact, the UN’s Food & Agriculture Organization (FAO) reports that raising livestock accounts for some 18 percent of all greenhouse gas emissions globally. Meanwhile, on the consumption side, cutting meat out of our diets is perhaps the most efficient way we can slash our personal carbon footprints. But eating only vegetables can make it hard to get enough protein, and that’s where bugs — with half or more of their body weight consisting of proteins — could play an important role in providing us with enough sustenance to feed ourselves, especially as our population surges to nine billion by 2050.

Proponents of eating bugs argue that emissions from so-called “insect farming” — that is, growing bugs for the express purpose of feeding humans and/or animals with them — is a much more energy- and emissions-efficient way to produce protein than traditional forms of livestock agriculture. “If we bartered beef, pork or chicken for a handful of insects, the environmental impact of our animal-protein intake would drop dramatically,” says Canadian environmentalist David Suzuki. “Insects are especially effective at converting their food because they’re cold-blooded and therefore waste less energy to keep warm.”

If you’re curious about edible insects, why not try some? Lewiston, Maine-based EdibleInsects.com ships edible insects coast to coast. UK-based PureGym is a big proponent of deriving dietary protein from insects, and offers several seemingly tasty recipes on its website and YouTube channel. Creamy Mealworm and Coconut Noodles, anyone?

Of course, just because crickets, ants, cockroaches and worms are becoming more common as food delicacies doesn’t mean that eating them is new for humans. The FAO points out in its “Edible Insects” report that while bugs have always been part of human diets, recent innovations in so-called “mass-rearing systems” mean we can produce a lot more insect-based protein than we used to: “Insects offer a significant opportunity to merge traditional knowledge and modern science in both developed and developing countries.”

Suzuki couldn’t agree more: “Emerging entotechnologies (from the Greek root entomo, for ‘insect’) bring together applications that focus on what insects do best.” For instance, food waste or agricultural residue is fed to fly larvae, which in turn is used as a meat-free but protein-rich livestock feed. “[L]arvae have voracious appetites for fruit and vegetable residues and could help improve the way we handle…organic waste,” reports Suzuki. “It’s a way to give a second life to stale food, rather than sending it to compost bins or biogas plants.”

“Considering that nearly 45 percent of fruit and vegetables produced worldwide is wasted, this is not a fringe idea,” says Suzuki. “After feeding the hungry with the highest quality unsold portions of our food, we could feed our breeding animals with insects raised on organic residues from grocery stores and restaurant kitchens.”

Contacts: David Suzuki’s “Save The Planet: Eat An Insect,” davidsuzuki.org/story/save-planet-eat-insect/; FAO’s “Edible Insects,” fao.org/3/i3253e/i3253e.pdf; PureGym, puregym.com.


Underground mycelium networks can absorb and break down a wide range of natural and man-made compounds, and that’s why we’re using them to clean up contaminated sites naturally. Credit: Kirill Ignatyev, FlickrCC
Dear EarthTalk: How is it that fungi can help clean up contaminated soils? — M. Sharpe, Canton, CT

Like animals, fungi derive energy by breaking down large molecules into smaller compounds. They do so by secreting enzymes and acids onto whatever it is they intend to consume, and then absorbing the byproducts of this digestion process. While fungi primarily consume biological matter (like dead wood), their enzymes can also break down a wide array of man-made compounds. In fact, fungi are so good at this, we’re now employing them to clean up contaminated soils via a technique known as mycoremediation.

Of course, these fungi are just doing what they evolved to do eons ago. Underneath our feet, massive fungal networks run through the soil, with many fungal species developing a symbiotic relationship with plants, whereby a part of the fungus (the mycelium) grows adjacent to — and sometimes inside of—the roots of the plant. The mycelium is capable of breaking down and transporting nutrients and minerals essential for the plant’s survival. After detecting and digesting these compounds, the mycelium ferries them to the plant’s roots, where they’re absorbed. In exchange, the plant releases compounds that are vital for the fungi’s survival.

It’s the fungi’s ability to break down and/or transport compounds that make them useful for restoring damaged soils. Often, these soils have been saturated with compounds made up of dangerous — and relatively large — molecules. By breaking these molecules into smaller pieces, fungi help to reduce their toxicity. In other instances, soils are contaminated with fundamental elements such as cadmium, arsenic, and mercury, which can’t be broken down. However, fungi still have the ability to uptake and transport these substances, and to eventually concentrate them in their fruiting bodies (mushrooms). We can then remove the fruiting bodies, and the contaminated ecosystem will be one step closer to regaining health.

Fungi can break down and/or absorb a wide range of compounds, including oil and other petroleum products, PAHs, PCBs, PCPs, neurotoxins, airborne pollutants, synthetic dyes, cadmium, lead, arsenic, mercury, copper, dioxins and organophosphates.

If fungi are so effective at cleaning up our environment, why isn’t this technique more widespread? For starters, it’s a slow process. As with any biological strategy for environmental clean-up, mycoremediation is limited by the speed of metabolism. If a polluted area needs to be cleaned quickly, other options may be better. Another issue with mycoremediation is that it often fails to completely rid soil of a given toxic compound, instead simply reducing the concentration. It can also be hard to justify economically, as no one wants to eat a mushroom full of heavy metals.

However, the biggest reason for mycoremediation’s relative lack of fame and use might simply be a lack of data from field tests. It’s a relatively new technique, without many case studies to support its use (despite a good amount of lab testing). Thankfully, this situation is changing. In 2017, for example, a large batch of oyster mushrooms was used to remediate soil damaged by California wildfires. The same variety of fungus has also been used to clean up oil spills and other toxic messes.

Contacts: Fantastic Fungi Film, fantasticfungi.com; “Mushroom as a product and their role in mycoremediation,” ncbi.nlm.nih.gov/pmc/articles/PMC4052754/; “Untapped potential: exploiting fungi in bioremediation of hazardous chemicals,” nature.com/articles/nrmicro2519.

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