Trees Save Big Cities $500 Million Each Year

iStock
iStock

As if you really needed another reason to hug a tree: Scientists writing in the journal Ecological Modeling say trees in big cities deliver more than $500 million in environmental benefits every year.

A tree is a marvel of biology. Unfussed by the pull of gravity, it sucks water upward; unembarrassed by its resourcefulness, it makes food out of the waste gases we leave behind. And that’s just what it does for itself; for us, it does even more, cleaning our air, beautifying our neighborhoods, improving our health and well-being, reducing our energy use, and helping us beat the heat.

"Trees have direct and indirect benefits for cooling buildings and reducing human suffering during heat waves," lead author Theodore Endreny of the SUNY College of Environmental Science and Forestry said in a statement. "The direct benefit is shade which keeps the urban area cooler, the indirect benefit is transpiration of stormwater which turns hot air into cooler air."

Endreny and his colleagues wondered how these qualitative effects might translate into dollars, or rubles, or rupees. The researchers used a tool called i-Tree Eco to estimate the amount of tree cover in 10 huge cities: Beijing, Buenos Aires, Cairo, Istanbul, London, Los Angeles, Mexico City, Moscow, Mumbai, and Tokyo.

These densely packed megacities are home to almost 10 percent of the entire human population of Earth—people whose lives often depend on natural environments outside city limits.

“What is, however, most often disregarded,” the authors note, “is that nature conservation in the city can also contribute to human well-being benefits. The most common mind set separates cities from the rest of nature, as if they were not special kinds of natural habitats.”

Their results showed that those urban natural habitats occupied about 21 percent of each megacity landscape. That’s a lot of tree cover, but there could be a lot more; on average, the researchers found another 19 percent of land that could be given over to vegetation.

The data suggested that filling this space with trees could increase environmental and cost benefits by an average of 85 percent.

As they are now, the trees are already saving megacities gobs and gobs of money—about $1.2 million per square mile, or $35 per resident, per year.

"Placing these results on the larger scale of socioeconomic systems makes evident to what extent nature supports our individual and community well-being by providing ecosystem services for free," co-author Sergio Ulgiati of Italy’s University Parthenope said in the statement.

"A deeper awareness of the economic value of free services provided by nature may increase our willingness to invest efforts and resources into natural capital conservation and correct exploitation, so that societal wealth, economic stability and well-being would also increase."

How to Build an Igloo, According to a Canadian Film From 1949

iStock.com/vovashevchuk
iStock.com/vovashevchuk

Centuries before you started building snow forts in your backyard, the Inuit had mastered using snow as construction material. This 1949 video, produced by the National Film Board of Canada (and with narration that uses some outdated terminology), illustrates how exactly people native to the Arctic can erect warm, temporary homes using nothing but a knife and the snow beneath their feet. The artifact was spotted by The Kid Should See This.

The igloo (or iglu in Inuktitut) in this footage takes around 90 minutes to erect, but a similar structure can be built by a skilled person in as little as 40 minutes. To put together the shelter, the two men carve up firm, packed snow into blocks that are about 2 feet tall, 3 feet wide, and 4 inches thick.

After the first row of blocks is placed in a circle on the ground, the builder slices a section of the blocks to create a slope. Each row that's placed on this foundation will spiral upward, creating a shape in which the blocks support their own weight. By the time the keystone block is fitted into the top, the igloo is strong enough to support the weight of a man.

The final steps are carving a doorway out of the bottom of the structure and plugging up the cracks with additional snow from outside. Even on a frigid Arctic night, the temperature of a well-insulated igloo can reach 40 degrees above the temperature outside. And the warmer the igloo gets over time, the stronger it becomes: The heat from the Sun and the bodies of the inhabitants melt the outer layers of the blocks, and that water eventually freezes to ice, giving the home more insulation and structural integrity.

If you aren't ready to build an igloo, here are some less intimidating snow projects to tackle this winter.

[h/t The Kid Should See This]

Charge Your Gadgets Anywhere With This Pocket-Sized Folding Solar Panel

Solar Cru, YouTube
Solar Cru, YouTube

Portable power banks are great for charging your phone when you’re out and about all day, but even they need to be charged via an electrical outlet. There's only so much a power bank can do when you’re out hiking the Appalachian Trail or roughing it in the woods during a camping trip.

Enter the SolarCru—a lightweight, foldable solar panel now available on Kickstarter. It charges your phone and other electronic devices just by soaking up the sunshine. Strap it to your backpack or drape it over your tent to let the solar panel’s external battery charge during the day. Then, right before you go to bed, you can plug your electronic device into the panel's USB port to let it charge overnight.

It's capable of charging a tablet, GPS, speaker, headphones, camera, or other small wattage devices. “A built-in intelligent chip identifies each device plugged in and automatically adjusts the energy output to provide the right amount of power,” according to the SolarCru Kickstarter page.

A single panel is good “for small charging tasks,” according to the product page, but you can connect up to three panels together to nearly triple the electrical output. It takes roughly three hours and 45 minutes to charge a phone using a single panel, for instance, or about one hour if you’re using three panels at once. The amount of daylight time it takes to harvest enough energy for charging will depend on weather conditions, but it will still work on cloudy days, albeit more slowly.

The foldable panel weighs less than a pound and rolls up into a compact case that it can easily be tucked away in your backpack or jacket pocket. It’s also made from a scratch- and water-resistant material, so if you get rained out while camping, it won't destroy your only source of power.

You can pre-order a single SolarCru panel on Kickstarter for $34 (less than some power banks), or a pack of five for $145. Orders are scheduled to be delivered in March.

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