The Key to Healthy Cities and Hearts Might Come from the Ground

Debra Burke grew up in the middle of a 500-acre forest in Hardin County, Kentucky. 

With no electricity or running water, she drank milk that wasn’t pasteurized, cooked with water from a nearby spring and ate vegetables caked with dirt.  

So when she moved an hour north to Louisville, Kentucky, 23 years ago, it was a bit of a culture shock, she told NationSwell.

She scoured the urban landscape for a forested pocket to meet her tree needs. “I kept looking for a community that reminded me of home,” she said.

After living in the city for about six months, she finally found it near Iroquois Park, a 725-acre expanse filled with a few of Burke’s favorites: red maples and white oaks. 

A few months ago, Burke was on her daily walk there when a yard sign caught her attention. It talked about the Green Heart project, a scientific study assessing how health is impacted by tree canopy, the percentage of a city shaded by trees.

Burke, a 59-year-old barber, is familiar with the power of trees — not just how they beautify cities, but how they transform the lives around them — so she wanted to get involved. Now she’s one of over 800 residents participating in a health assessment to track how trees and vegetation affect their cardiovascular health. 

Her neighborhood is one of the four neighborhoods in south Louisville that has embarked on a $15 million, five-year study that will once and for all answer if health is tied to an area’s tree canopy. The study launched in 2018 when researchers collected baseline information about the neighborhood’s air pollution and resident’s heart health. Over the next three years, they’ll plant trees and monitor those same residents. In 2022, they’ll observe any changes. 

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The Green Heart project will be the first controlled scientific study assessing the impact of tree canopy on heart health.

As early as 1984, researchers were beginning to understand the role greenery plays in health. Roger Ulrich watched as patients with tree-facing windows had shorter hospital stays compared to their counterparts who looked at brick walls. The links between health and vegetation have continued for decades. Scientists saw the benefits of trees in everything from absorbing auto emissions to cooling sidewalks. They studied how greenery correlates to decreases in stress levels, heart rates, muscle tension, asthma and blood pressure.  

There’s a well-known link between health and greenness. But an important component was missing from the story: a controlled scientific study. 

The Green Heart project will be the first-ever experiment to see if increasing an area’s tree canopy will improve residents’ health.

Ted Smith, the director of the Center for Healthy Air, Water and Soil at the University of Louisville’s Envirome Institute, compared it to a drug trial “except the drug is trees and bushes,” he told NationSwell. Researchers will use a control group and a test group to see if the “drug” is effective or not. 

In this study, a control group of two neighborhoods will not receive any changes to their environment, but the test group will. Test neighborhoods will have 8,000 trees and plants added to their lawns, backyards and public spaces. Green Heart’s team surveyed public and private land in search of gaps in greenery, and the greening team went door to door asking residents if they’d like trees to be planted in their yards for free. These trees will raise the community’s tree canopy by 10% — an amount that’s “consistent with the literature of seeing a clinical benefit,” Smith said.

After about a year and a half, researchers will look at whether health improved, worsened or stayed the same between the groups. 

While it’s a study that can apply to almost every urban environment, Louisville is a compelling place to start. The city’s average tree canopy is only 28% — 16% lower than the recommended percentage, Smith said. That means a little over a quarter of the city is shaded by trees, whereas a healthy city should have a canopy of 44%. Instead of increasing, Lousiville’s tree canopy has continued to decline. About 54,000 trees are lost in Louisville each year to factors like development, age and invasive species. 

In the four neighborhoods researchers are studying, the numbers are even lower. Their tree canopy averages out at just 22%. But it wasn’t just their low tree canopy area that made these neighborhoods strong candidates: They each have high owner occupancy, which means they’re less likely to be gentrified as a result of the greening; they’re decent sizes (about 40,000 residents cumulatively); and they’re ethnically and socioeconomically diverse.

“If we can provide some evidence that there is an important effect of greenness on human health, in particular, the risk of heart disease, then that will send a case in trying to preserve the tree canopy,” Aruni Bhatnagar, the director of the Center for Diabetes and Obesity Research at the University of Louisville and lead researcher for the study, told NationSwell. 

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Aruni Bhatnagar speaks at Green Heart’s tree planting.

The $15 million study is funded by the National Institutes of Health, which supports the medical testing, and The Nature Conservancy, which is funding the vegetation. Collaborators include the University of Louisville, Louisville’s metro government, Washington University in St. Louis, U.S. Forest Service, Cornell University and Hyphae Design Lab.

“You don’t see projects come together like this very often, and we’re really trying to make sure this isn’t the only time unusual funders get together to get things done that aren’t just being done,” Smith said. 

Before planting began, the Green Heart team found more than 800 residents to complete a health assessment. Hair samples, nail clippings, urine, blood and questionnaires were all collected to assess each individual’s health. In about two years, after all the planting is done, their health will be reassessed. 

Bhatnagar and other scientists will be looking for changes in their health. For heart health, they’ll look at arterial stiffness, where increased stiffness is associated with an increased risk for heart events.

Kentucky is part of the Coronary Valley, a region of the U.S. that has the highest coronary heart disease mortality rates. While this area has higher concentrations of heart deaths, it’s a risk that everyone faces, said Bhatnagar, who has spent his career at the intersection of heart health and nature.

“We can treat it with lots of different things, stents and statins and whatever, but it’s very hard to prevent,” he said. “So prevention approach is severely and sorely needed.”

Bhatnagar hopes this study could create a blueprint for other urban cities to follow.

“If we can provide some evidence that there is an important effect of greenness on human health, in particular, the risk of heart disease, then that will send a case in trying to preserve the tree canopy. ” Bhatnagar said. “Not just in Louisville, but I think globally.”

Beyond heart health, scientists are looking at other connections between trees and people. 

Smith, who is leading the ancillary studies, said the team is conducting additional research to look at variables like sleep, noise, asthma, depression, social cohesion and biodiversity. 

Overall the study has been well-received. 

The Green Heart team is present at town halls, neighborhood meetings and community events. They’re there to spread awareness about the study but also show that they’re not just planning on extracting data from the community — they’re there for the long haul.

Nicole George, one of the two council representatives in the study’s neighborhoods, said Green Heart’s presence has helped shaped community attitudes towards the study.

“Their commitment is not just planting the tree, collecting a little health survey data and leaving,” she told NationSwell. “Their commitment is to the community.”

So whether it was Green Heart members helping a resident clean debris after a tree fell on her home or sending a birthday card to a resident, this is more than just a study.

“We’re not here to fix your neighborhood or clean up your neighborhood,” Smith said. “We’re here to figure out how to have a healthier neighborhood.”

More: To Build a Healthier City, Atlanta Is Opening Its Schoolyards to Everyone

There’s a Way to Plant Trees Every Time You Search the Internet — and It’s Free

What if the next question you asked a search engine could help save the planet?
That’s the idea behind Ecosia, a free browser extension that uses advertising revenue from basic search queries to reforest our planet. Once the extension is installed on their browser, users are free to search the internet as they usually do — all while Ecosia collects a few cents from every click on a sponsored search result. 
For every 45 searches, Ecosia earns enough money to plant a tree. Through their efforts, they’ve been able to plant over 62 million trees since first launching in 2009.
Though the act of planting trees may sound simple on its surface, at scale, it might be one of the most effective means of stemming the catastrophic effects of carbon emissions on our planet. According to a July 2019 study in the journal Science, a sustained worldwide effort to plant 1 trillion trees is the most powerful lever we can pull to limit further global temperature rises and protect human life on our planet. 
Planting a forest roughly the size of the United States is an undoubtedly daunting task, but Ecosia makes it free and easy for anyone who uses the internet to play her part — and it’s catching on. According to Forbes, in 2018 Ecosia more than doubled the number of trees it had planted since its founding. 
It’s on track to beat that record again in 2019.
The company currently has tree-planting projects in 15 countries with strong forest ecosystems, including Brazil, Nicaragua, Haiti, Uganda and Indonesia. They partner with local organizations that have the expertise to plant and foster healthy new trees in their respective environments, helping to ensure the trees’ survival, improve biodiversity, and create employment opportunities in impoverished agricultural regions.
Ecosia also built its own solar plant to run all their servers on clean power, making the company carbon negative. “This means that if Ecosia were as big as Google, it could absorb 15% of all global CO2 emissions!” says its blog. “That’s enough to offset vehicle emissions worldwide.”
Of course, reforestation cannot solve climate change in a vacuum (and certainly one company cannot solve it alone). Global leaders will still need to focus on ending emissions from coal and gas while curbing deforestation so the influx of new trees won’t be negated by the rapid depletion of the world’s forests. 
But in the toolkit of environmental solutions, reforestation has the potential to be the most powerful, cost-efficient and scalable option we have. 
“The beautiful thing is that it is a universal issue,” Jean-Francois Bastin, the Science study’s lead author, said in an interview. “It can unify us against a common threat, where anyone can have a role to play, by acting on supporting the restoration of ecosystems, but also by changing the way we are living on the planet.” 
More: Sucking Carbon Out of the Air Is One Way to Help Save Our Planet

Could Acrophobia Help Save America’s Favorite Breakfast Juice? 

The fight to save Florida’s orange trees has literally been taken to a higher level.
In case you didn’t know, the state’s $9-billion-a-year industry has been crippled by “citrus greening,” a incurable disease carried by a bug called the Asian citrus psyllid. The bacteria, also known as huanglongbing, causes oranges, lemons, grapefruit, etc. to remain green and useless for consumption or sale. The only way that growers can manage the blight is by removing the infected tree before it wipes out an entire grove.
For a state that supplies 80 percent of America’s orange juice, this little bug is causing a giant problem. Just about every grove in the Florida — as well as every other citrus-growing locale here and around the world — has been infected by this bacteria. We previously noted that the Sunshine State already lost 8,000 jobs and $4.5 billion in crop damage. It’s also why wholesale OJ prices have just about doubled since 2000.
But as it turns out, scientists from the U.S. Department of Agriculture’s Agricultural Research Service in Puerto Rico and Florida have found that these invasive pests might have a weak-spot: heights.
MORE: Despite Pests and a Lack of Experienced Help, This Woman Found Success Raising Organic Produce
For the two-year study (recently published in the Journal of Economic Entomology), researchers analyzed the Asian citrus psyllid populations at 17 different sites in Puerto Rico, ranging from 10 to 880 meters above sea level. Their findings showed that as elevations increased, the number of insects dipped. Intriguingly, at 600 meters above sea level, the population dropped to zero.
“We found the psyllid at all sites below 600 meters but none above it. At 500, we had a high level of psyllids,” David Jenkins, USDA researcher and co-author of the study, tells the Washington Post. It’s unclear why the psyllids don’t thrive in extra-elevated areas, but it’s suggested that they don’t like the difference in air pressure, temperature, oxygen levels, ultraviolet light or perhaps the food supply found in high elevation is unsuitable to their diets.
So how can the citrus industry apply this to their own groves? Planting nurseries above 600 meters is one way, the authors of the study suggest. Also, as Jenkins tells the Post, “if atmospheric scientists can somehow duplicate conditions near the trees, the psyllid could be controlled.”
The new research has already sparked interest. “In fact some people in Florida have contacted us,” Jenkins adds. “They want to conduct studies with pressure, as far as pressurizing tree. They’ve got atmospheric scientists looking at that kind of stuff. We’re not the ones that have the ideas on how to use it, but somebody out there may have the idea to make this practical.”
With genetic engineering and even parasitic wasps being touted as possible remedies, growers are desperate to save their trees. With any luck, the solution to keeping orange juice on the table will be found on higher ground.

This Southern City Is Looking to Trees as a Way to Beat the Heat

You probably don’t know this, but Louisville, Ky., is an island. Yes, you read that correctly.
Granted, Louisville is not a real island, but it’s an urban heat island — a phenomenon where a city’s center is much hotter than its surrounding areas. Due to the abundance of darkly paved areas, the heat is stored and released throughout the day and night, which prevents the area from cooling down after sunset. While this doesn’t cause pollution, it does heighten the effects.
“Cities essentially create their own climates,” urban heat expert Brian Stone Jr. explains to Politico. “And the urban heat island effect is one way to measure that. There’s a heat island effect, really, in every large city.”
With an urban core that’s 20 degrees warmer than the surrounding area, Louisville ranks as the number one heat island in the nation — resulting in higher electric bills for residents, more coal burned, disruptions in the city’s ecosystem because of hotter storm water and even death by heat. And while this designation isn’t something to be proud of, the city’s effort to reverse it is.
In 2012, there were 39 heat-related deaths, which spurred the city into action. Louisville created a tree commission to assess and revive trees that were damaged by natural disasters because it believes that it’s imperative to maintain and replace existing trees in addition to planting new trees. Plus, it has spent $115,000 on tree assessments, received $135,000 in grants to study the urban heat island (the first ever in its kind) and planted over 12,000 trees since 2011.
Louisville has also hired a director of sustainability and an urban forester to address the present and the future. Local nonprofits are also getting involved in the solution. Louisville Grows holds volunteer planting days where the group plants trees across the downtown. And the nonprofit American Forests assessed the approximate percentage of trees needed to combat the urban heat island, which stands at about 20 percent in the downtown area, but Louisville only has about eight percent, reports Politico.
“It’s really important to us that while we’re planting the trees,” Louisville Grows executive director Valerie Magnuson says. “We’re thinking in terms of a tree that’s going to be living for 100 years or much longer, and is going to carry on after we’re all gone.”
MORE: Why a New Start-Up Is Paying Customers to Save Water

This Is Probably the Smartest Thing You Can Do Every Christmas

Nothing says Christmas like the piney fragrance of a beautifully decorated fir, pine or spruce.
But not to be a total Grinch, these noble evergreens don’t have it so easy when the holidays come around. Christmas trees, as writer Meghan Walsh points out on OZY, are basically bred to be cut down and sent to the curb after a few weeks. And for any Christmas lover/eco-conscious person alike, that just seems like a big waste.
Alongside the mountains of dead trees that pile up each year, Christmas trees (real or fake) cost a pretty penny. The website pointed out that just last year, Americans purchased 33 million real trees to a cost of $1.16 billion, and 14.7 million plastic ones at $1.19 billion.
These winter icons deserve much more respect, and that’s why in 2008, Scott “Scotty Claus” Martin decided to start The Living Christmas Company in Los Angeles so customers could simply rent a tree and have it delivered right to their doorstep. After Christmas is over, the trees are picked up and go straight back to the nursery.
MORE: How a 20,000-Year-Old Tree Is Finding New Life in Texas
Fans of ABC’s “Shark Tank” might remember that two years ago, Martin’s genius idea got a $140,000 investment from billionaire Mark Cuban for a 40 percent stake in the company. Martin was also recently featured in the series’ “Success Stories” segment during its 100th episode, during which he explains how his company has since grossed half a million dollars after Cuban’s investment and is projected to reach $300,000 after the holiday season.
Additionally, according to the OZY report, the Living Christmas Company has recently expanded operations in Northern California after Dean Rafini, a Bay Area firefighter, fell in love with the idea.
Only NorCal and SoCal residents can rent trees from the company, but for those of you who’d also like to cut down on Christmas tree waste, consider buying a potted evergreen and planting in your yard after the holidays (click here for tips) instead of buying a cut tree.

Which Is Better, Hand Dryers or Paper Towels?

For as long as there have been public restrooms, there’s been a dilemma we’ve all faced after we wash our hands: Paper towel or hand dryer?
Finally, we have an answer, thanks to the team at AsapSCIENCE. As it turns out, there’s definitely a greener choice, while the other is better for germaphobes.
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PAPER TOWELS:
Pro: Moisture is what spreads bacteria the most, so for people who can’t take the time for a hand dryer to completely dry their mitts, paper towels can do the job in 5 to 10 seconds. Friction also removes bacteria as well.
Con: This fact should scare you: 13 billion pounds of this throw-away product are used in the United States alone. To produce one ton of paper towels, it takes 17 trees and 20,000 gallons of water.
HAND DRYER:
Pro: It requires fewer resources and prevents deforestation and high carbon emissions.
Con: Using one takes at least 45 seconds to reduce hand moisture by 97 percent, even though most people only dry their hands for about 22 seconds. Some dryers might also blow bacteria back onto your paws due to contaminated bathroom air.
WINNER:
It really comes down to preference. But it seems the real answer is to wash your hands properly (scrubbing with soap for at least 20 seconds!) and you won’t even need to use either option to get rid of any germs remaining on your hands. After all, it’s important to keep your hands clean — about 80 percent of infectious diseases are transmitted by touch.
As the AsapSCIENCE video explains, if you must use a paper towel, try to use as few as possible. For hints on how to do that, check out this adorable video of Umatilla County District Attorney Joe Smith demonstrating how to dry your hand with a single sheet of paper towel.
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DON’T MISS: This Small Change to Toilet Paper Will Reduce Its Big Environmental Impact

Do Trees Actually Cause Climate Change?

There’s probably nothing more symbolic of the green movement than a tall, leafy tree. Along with protecting our forests, planting a tree to offset one’s carbon footprint has now become de rigueur in fighting climate change.
However, in the recent New York Times op-ed, “To Save the Planet, Don’t Plant Trees,” Yale professor Nadine Unger smacks several holes in conventional green wisdom. And to no one’s surprise, it’s causing some backlash in the scientific community.
Unger’s article boils down to three (controversial) points about trees and forests:
1. Trees give off harmful pollution. “Trees emit reactive volatile gases that contribute to air pollution and are hazardous to human health…As these compounds mix with fossil-fuel pollution from cars and industry, an even more harmful cocktail of airborne toxic chemicals is created.”
2. Planting forests in colder places might cause the planet to bake. “The dark color of trees means that they absorb more of the sun’s energy and raise the planet’s surface temperature….Planting trees in the tropics would lead to cooling, but in colder regions, it would cause warming.”
3. Stopping deforestation is not the best way to mitigate global warming. “The science says that spending precious dollars for climate change mitigation on forestry is high-risk: We don’t know that it would cool the planet, and we have good reason to fear it might have precisely the opposite effect. More funding for forestry might seem like a tempting easy win for the world leaders at the United Nations, but it’s a bad bet.”
If your head is spinning, you’re not alone. After the article came out, a slew of top scientists came out to strongly rebuke Unger’s article.
MORE: 3 Reasons Why Sunday’s Historic Climate March Could Be the Start of Something Huge
“Nadine Unger argues that reducing deforestation and planting trees won’t help fix climate change but will rather make it worse,” Steve Schwartzman, Director of Tropical Forest Policy writes. “One might ask how the 2,000-plus scientists and experts on Intergovernmental Panel on Climate Change (IPPC) got this one wrong — they found tropical deforestation a major source that must be reduced to control climate change – but in fact it’s Unger who’s way out on a limb here.”
And in another response called “Dr. Unger’s Four Scientific Fouls,” Michael Wolosin of Climate Advisers picks apart each of Unger’s points and concludes, “Normally, this type of scientific debate would take place in specialist journals with lengthy peer review processes to ensure accuracy. And for good reason – it is a process that keeps scientists from jumping to conclusions that aren’t implied by their work, and that should not be cited as fact by others.”
There’s also this piece that was signed by 30 scientists, including six members of the National Academy and four members of the Intergovernmental Panel on Climate Change.
Unger has since defended herself where she lists all of the sources that she points to in the Times op-ed. She also points out, “The primary key to solving the global climate problem is the transformation of our energy system into one that does not use the sky as a waste dump for our greenhouse gas pollution.”
Well, it appears Unger does have a point there. Simply put, we can’t treat our planet like a trash can. As we’ve previously reported, there are multiple ways to preventing climate change, including leaving our precious forests alone. But really, according to near scientific consensus, the best way to stop climate change is by cutting carbon pollution through conserving energy and curbing our reliance on fossil fuels.
Hopefully this is something we can all agree on.
DON’T MISS: The Top 5 Ways to Fight Global Warming

A Big Break in the Mystery That’s Terrorizing Florida’s Citrus Crops

For nearly a decade, the citrus industry has been crippled by a deadly and incurable disease known as citrus greening. The bacteria — also called Huanglongbing or “yellow dragon disease” — causes fruit to remain green and useless for consumption or sale. The only way that growers can manage the disease is by removing an infected tree before it wipes out the whole grove. According to the Gainsville Sun, the blight has spread to all 32 counties in Florida, affecting 75 percent of the state’s citrus crop. Another startling stat: Since 2006, citrus greening has reportedly cost the Sunshine State 8,000 jobs and $4.5 billion in crop damage.
But government officials and scientists are fighting back. The U.S. Department of Agriculture recently received $20 million to take on the disease. And the Gainsville Sun reports that University of Florida scientists have cracked the DNA of the nasty bacterium, Candidatus liberibacter asiaticus, that’s believed to be the culprit behind citrus greening. “We are able to look at the genome and tell what it has no defenses against,” plant pathologist Dean Gabriel told the publication.
MORE: What Do You Get When You Combine Wheat, Woody Harrelson and Environmental Awareness?
One reason this bug has been stumping hundreds of scientists for years (even with $80 million in prior funding) is that the bacteria won’t grow in a petri dish, making it difficult to test in labs. It’s also super elusive — as Gabriel said, “We have no idea where it is in an infected tree.” However, he remains optimistic, adding that a cure could be five years away. For Florida citrus farmers, the solution can’t come soon enough.

Is This the Tree That Revitalizes Oregon’s Lumber Industry?

Oregon is known for its lumber, which supports a multitude of other industries in the United States, from the production of paper pulp to couches. Unsustainable tree harvesting would mean the eventual end of what is, for Oregon, an extremely vital trade. An innovative logger, GreenWood Resources, is attempting to revitalize the foresting industry with its fast-growing hybrid poplars, which reach maturity in about 10 years. Poplar monoculture may not be environmentally optimal, but this certainly represents a step toward maintaining the viability of foresting in Oregon. Sustainable Business Oregon has a photo gallery of GreenWood’s operation.