Tiny Forests' Big Benefits

Tiny Forests Can Have Big Benefits
Nicholas Johnson
The Gazette, February 13, 2024, p. A6
Cedar Rapids and Iowa City have been honored Arbor Day Foundation “Tree City USA” communities for over 40 years.

We know the benefits tree projects provide – air quality, cooling, community cohesion, improved health.

The Cedar Rapids derecho on Aug. 20, 2020, made national headlines after gusts up to 140 mph destroyed or seriously damaged nearly 700,000 trees.

Current news is our share of the $1 billion Forest Service grant for local trees, ReLeaf’s plan to replace nearly 50,000 of the former trees, NOAA’s identification of our “heat islands,” and near universal community support for these projects.

We are aware that it’s getting warmer. Many days this month have been 30 degrees or more above average. We may not be aware that The Lut Desert (Iran) and Sonoran Desert (Mexico) have recorded temperatures over 175 degrees. That workers in Kuwait City and Basra, Iraq, need to start in the middle of the night and quit at 7:20 am for breakfast and home to avoid excessive heat. Or that the Sun is 16 million degrees at its core.

When Dean Martin sang that he was “praying for rain in California” it was “so the grapes will grow and they can make more wine.” If it didn’t rain he could always go back to his favorite Old Fashioned.

When Iowa farmers pray for rain no alcohol is a viable substitute. And when the hot, dry, cracked soil no longer gives birth to corn and beans, Iowa’s economy crashes along with farmers’ dreams.

Fortunately, like a new fashion industry design (think torn jeans), just when we need a comfortable breeze of good news, along comes a new approach to trees.

It’s called “tiny forests.” In 2006 Japanese botanist Akira Miyawaki was honored for this contribution. In addition to Japan, they’re now popular in Europe, Asia, South America, Africa, India, Russia and the Middle East.

Here are the highlights.

Tiny forests are, well, tiny. No rigid rules on size, so think tennis court.

How do they differ from trees planted between the sidewalk and road along a city street? Tiny forests are an effort to recreate a crowded plot with naturally enriched soil, and none but indigenous shrubs, groundcover and trees fighting for the sunlight. Like a small piece of our western vacation lands.

I hear you asking – as my doctor queried when I proudly told him I’d lost five pounds – “Why would you want to do that?”

Used in urban heat islands, parks and developments as a supplement, not substitute, for other tree planting projects, they have those projects’ advantages plus many more.

With three-to-six times the tree density of a young forest they grow faster – 5 to 10 feet a year. Density creates microclimates, attracting a greater variety of birds and pollinators. Rapid growth creates more carbon dioxide capture sooner. Greater cooling. Soil that reduces erosion and runoff while refilling aquifers. Weed suppression. Low or no maintenance. Need less land than scattered trees. [Photo credit: wikimedia commons; Tiny Forest 9 months after planting!]

Sometimes major challenges have tiny solutions.

Nicholas Johnson will email you his “tiny forest” sources if you email a request to mailbox@nicholasjohnson.org

SOURCES Cedar Rapids trees. “Forestry,” Cedar Rapids, https://www.cedar-rapids.org/residents/resident_resources/forestry.php (“Tree City USA Recognition The City of Cedar Rapids has been recognized as a Tree City USA by the Arbor Day Foundation for more than 40 consecutive years. We have the longest consecutive record of any city in the state of Iowa.”)

Iowa City trees. “Forestry,” Iowa City, https://www.icgov.org/government/departments-and-divisions/parks-and-recreation/forestry “Tree City, USA Iowa City is proud to have been named a Tree City USA annually since 1979. Only one city in Iowa, Cedar Rapids, has been a recipient over a longer period of time than Iowa City.”)

Benefits of trees. “22 Benefits of Trees,” TreePeople, https://www.treepeople.org/22-benefits-of-trees/ (sample selections: climate change, cleaner air, oxygen source, heat reduction, water control, erosion protection, noise reduction, soil improvement, beautification, physical and mental health.)

Cedar Rapids derecho. “Derecho,” Cedar Rapids, https://www.cedar-rapids.org/derecho/review.php (“On August 10, 2020, Cedar Rapids was confronted with an unprecedented disaster that impacted the entire community. . . . Recognized as the most destructive severe thunderstorm in the United States history, the derecho damaged thousands of homes and businesses. The derecho also destroyed 669,000 trees causing an enormous amount of debris.”)

Examples of national coverage:

Bryan Pietsch, Aimee Ortiz and John Schwartz, “In Derecho’s Wake, More Than 250,000 in Midwest Struggle Without Power; Residents in Iowa, Illinois and surrounding states were still without electricity days after Monday’s storms brought hurricane-force winds,” New York Times, August 13, 2020, https://www.nytimes.com/2020/08/13/us/derecho-iowa-storm.html

Bob Henson, “Iowa derecho in August was most costly thunderstorm disaster in U.S. history; NOAA estimates damage at $7.5 billion, higher than many hurricanes,” The Washington Post, Oct. 17, 2020, https://www.washingtonpost.com/weather/2020/10/17/iowa-derecho-damage-cost/ (“Numerous locations clocked gusts over 110 mph. The winds laid waste to millions of acres of crops, severely damaged or destroyed hundreds of homes, and brought down many thousands of trees. “One could make a strong case that this is the most destructive individual thunderstorm cluster on record in terms of damage cost,” said Steve Bowen, head of catastrophe insight at the insurance broker Aon, in an email. Aon released an initial damage estimate of $5 billion for the derecho, not yet including agricultural impacts. . . . The highest estimated gust, based on the partial destruction of an apartment complex in Cedar Rapids, was 140 mph. Gusts that strong are comparable to the peak that one would expect in an EF3 tornado or major hurricane. Parts of five Iowa counties were struck by wind gusts estimated at 110 to 140 mph.”)

Forest Service grant; ReLeaf plans. Marissa Payne, “In USDA’s $1.1 billion investment in tree planting, Cedar Rapids’ ReLeaf reforestation effort awarded $6 million; Iowa communities, Department of Natural Resources receive $15.7 million through Forest Service grants,” The Gazette, Sep. 14, 2023, https://www.thegazette.com/federal-government/in-usdas-1-1-billion-investment-in-tree-planting-cedar-rapids-releaf-reforestation-effort-awarde/ (“In a move to expand equitable access to trees and green spaces nationwide, U.S. Agriculture Secretary Tom Vilsack on Thursday announced an award of $6 million toward Cedar Rapids’ effort to reforest the city after the 2020 derecho toppled most of the city’s tree canopy. Gathered at Greene Square in the heart of Cedar Rapids, federal officials shared Cedar Rapids is among 385 recipients of $1.13 billion in U.S. Forest Service grants that will help communities grow tree cover in urban spaces and provide Americans with the health benefits that trees offer. . . . The funding . . . is intended to expand equitable access to nature while making communities more resilient to extreme heat, storm-induced flooding and other effects of the human-caused climate crisis. Locally, Thursday’s announcement moved the city of Cedar Rapids and Trees Forever closer to the $37 million needed to fund their ReLeaf partnership to replenish the trees downed in the derecho, ReLeaf partnership to replenish the trees downed in the derecho, the costliest thunderstorm in U.S. history. The unprecedented storm wiped out more than two-thirds of Cedar Rapids’ tree canopy, about 669,000 trees. . . . Specifically, the ReLeaf plan calls for planting about 42,000 trees on public parks and rights of way over 10 years with a focus on place-making and equitably restoring tree cover in vulnerable neighborhoods. The plan envisions trees as a means of strengthening social bonds in the community by promoting volunteerism.”)

NOAA’s heat islands. “Spot the Hot,” The Hot-Heat Mapping Campaign, Cedar Rapids, https://www.cedar-rapids.org/local_government/sustainability/SpotTheHot.php (“Residents in Cedar Rapids and Iowa City had the opportunity to serve as community scientists to gather temperature data I hottest parts of our Corridor communities as part of a National Oceanic and Atmospheric Administration (NOAA) heat island project. The City of Cedar Rapids, along with Iowa City, recently was named one of 18 communities in the U.S. to participate in the NOAA Urban Heat Island (UHI) mapping campaign, and we received grant funding from NOAA for this project. UHIs are areas with fewer trees and more pavement to absorb heat and create heat pockets in communities, in contrast with areas that feature more trees, green spaces, and less asphalt. UHIs are detrimental to public health because of these created heat pockets. The NOAA UHI mapping campaign engaged community volunteers to help collect data in their neighborhoods by utilizing provided sensors mounted on their vehicles; the sensors recorded temperature, humidity, time, and location.”)

Near universal community support. Marissa Payne, “In USDA’s $1.1 billion investment in tree planting, Cedar Rapids’ ReLeaf reforestation effort awarded $6 million; Iowa communities, Department of Natural Resources receive $15.7 million through Forest Service grants,” The Gazette, Sep. 14, 2023, https://www.thegazette.com/federal-government/in-usdas-1-1-billion-investment-in-tree-planting-cedar-rapids-releaf-reforestation-effort-awarde/ (“Vilsack told reporters the combination of community leadership, nonprofit organizations, faith-based organizations and other partnerships behind ReLeaf Cedar Rapids made it a compelling application within the state of Iowa and a fitting location to spotlight in unveiling the grants. ‘What really struck me was how comprehensive and how excited and how passionate people are for this program in Cedar Rapids,’ . . . The city has committed at least $1 million annually toward ReLeaf for 10 years . . .. ReLeaf has secured about $3.5 million in private support so far . . ..”)

30 degrees warmer this year. Corey Thompson, “Exceptional warmth continues, before rain and storm chance brings change,” KCRG, Feb. 6, 2024, https://www.kcrg.com/2024/02/06/exceptional-warmth-continues-before-rain-storm-chance-brings-change/ (“A warming trend continues into Wednesday and Thursday, owing to an increase in southeasterly winds. These will help to pull in those warmer highs, which head toward the upper 50s on Wednesday, and likely break through the 60-degree mark on Thursday. More records are possible on Wednesday, and we will likely wipe out records area-wide on Wednesday as highs surge toward 30 degrees or more above normal. Cedar Rapids has never seen such warmth for so long this early in the year . . ..”)

Alan Halaly, “West’s ‘hot drought’ is unprecedented in more than 500 years,” Las Vegas Review-Journal, Feb. 1, 2024, https://www.reviewjournal.com/news/science-and-technology/wests-hot-drought-is-unprecedented-in-more-than-500-years-2991687/ Also, The Gazette, Feb. 3, 2024, p 6: (LAS VEGAS — There’s no precedent in at least five centuries for how hot and dry the West has been in the last two decades, new research asserts using analysis of tree rings. The study, published in late January, adds to an ever-growing slew of research that suggests human-caused climate change is warming the earth in ways never seen before. It furthers other research like one study, published last year, that showed the West’s conditions over the last 20 years are the driest in 1,200 years because of climate change.”)

Ian Livingston, "Central, eastern U.S. bask in record winter warmth; At least 350 warm-weather records have been set this week alone," Washington Post, Feb. 9, 2024, https://www.washingtonpost.com/weather/2024/02/09/record-high-temperatures-midwest-greatlakes-climate/ ("Abnormally warm weather has [set] hundreds of records. Now some of this warmth is oozing toward the East Coast. Already, at least 350 warm-weather records have fallen, and two more days of springlike warmth are on the way from the Great Lakes to the Mid-Atlantic. . . . Since the beginning of February, temperatures in the nation’s northern tier have climbed to nearly 40 degrees above normal at times. . . . So far, February is the warmest or second-warmest on record for most of the Midwest and Great Lakes regions, according to Weather Service data.")

Lut & Sonoran deserts. Richard Stone, “Move over, Death Valley: These are the two hottest spots on Earth; Two places hold the record for highest surface temperatures on the planet,” Science, May 19, 2021, https://www.science.org/content/article/move-over-death-valley-these-are-two-hottest-spots-earth (“Death Valley holds the record for the highest air temperature on the planet: On 10 July 1913, temperatures at the aptly named Furnace Creek area in the California desert reached a blistering 56.7°C (134.1°F). Average summer temperatures, meanwhile, often rise above 45°C (113°F).

But when it comes to surface temperature, two spots have Death Valley beat. A new analysis of high-resolution satellite data finds the Lut Desert in Iran and the Sonoran Desert along the Mexican-U.S. border have recently reached a sizzling 80.8°C (177.4°F).

Kuwait and Basra. “Extreme Heat Will Change Us; Half the world could soon face dangerous heat. We measured the daily toll it is already taking,” New York Times, Nov. 18, 2022, https://www.nytimes.com/interactive/2022/11/18/world/middleeast/extreme-heat.html (Basra and Kuwait: "By 7:22 a.m., it was too hot to keep going on the roof, so they ate breakfast in the shade and switched to indoor tasks. At 9 a.m., they quit for the day.")

Sun temperature. “Sun,” Wikipedia, https://en.wikipedia.org/wiki/ (“Sun Sun’s diameter. 864,600 miles Sun’s distance from Earth. 93,000,000 miles Sun’s temperature on surface; at core. Surface atmosphere 9,000,000 oF [8,999,540 oF] Core 16,000,000 oF [15,700,000 oF] A sphere that size could hold 1.3 million Earths. “Image of 1 Million Earths Inside the Sun,” Business Insider, Jan. 30, 2015, https://www.businessinsider.com/image-of-1-million-earths-inside-the-sun-2015-1)

Dean Martin song. “Little Old Wine Drinker Me,” MOJIM, https://mojim.com/usy123185x45x6.htm (“Little Old Wine Drinker Me”

I’m praying for rain in California, So the grapes can grow And they can make more wine”)

Dean Martin’s favorite drinks. Johathan Wells, “Here’s how to drink like the Rat Pack; From Frank Sinatra’s favorite Scotch whisky to Dean Martin’s cocktail of choice, here’s how to drink like the famous entertainers,” Gentleman’s Journal, Feb. 5, 2024, https://www.thegentlemansjournal.com/article/heres-how-to-drink-like-the-rat-pack/ (“He [Dean Martin] enjoyed a frequent glass of Jack Daniel’s over ice — and even launched his own bourbon, Dino’s, in 1959 (part of a liquor line that also included a vodka and a Scotch whisky). Curiously, however, Martin preferred his Old Fashioned — a cocktail traditionally mixed with bourbon — made with Scotch.”)

Agriculture in Iowa’s economy. Caitlyn Lamm, “Ag is vital to Iowa’s economy,” Iowa Farm Bureau, March 30, 2022, https://www.iowafarmbureau.com/Article/Ag-is-vital-to-Iowas-economy (“Iowa agriculture is responsible for a direct economic output of $88.3 billion and more than 315,000 jobs contributing $17.57 billion in wages, according to the sixth annual Feeding the Economy report. . . . Iowa agriculture supports 801,000 jobs and a $204 billion economic output. Iowa agriculture also has an export value of $6.56 billion.”)

“Iowa,” Sheppard Software, https://www.sheppardsoftware.com/usaweb/snapshot/Iowa.htm (“Economy Farms make up about 92 percent of Iowa’s land; only Nebraska has a higher percentage of farmland. About one-third of the best farmland in the United States is located in Iowa. Most of the state’s residents are in some way dependent upon Iowa’s fertile soil and many crops.”)

“Study Measures Significance of Agriculture to Iowa Economy,” Iowa State University, Extension and Outreach, 2009, https://www.extension.iastate.edu/news/2009/oct/161501.htm (Though a little dated, still ballpark indicators. “Production agriculture and ag-related industries directly and indirectly employ one of every six Iowans (or 17 percent of the state’s workforce), based on 2007 Census of Agriculture data. They also are responsible for adding $72.1 billion to the state’s economy, or 27 percent of the state’s total. This represents a 2 percent increase over a previous analysis . . ..”)

Tiny forests – description and benefits. See generally, "Pocket Forests," Wikipedia, https://en.wikipedia.org/wiki/Pocket_forest

Cara Buckley, “Tiny Forests With Big Benefits; Native plants crowded onto postage-stamp-size plots have been delivering environmental benefits around the world — and, increasingly, in the U.S., New York Times, Aug. 26, 2023, https://www.nytimes.com/2023/08/24/climate/tiny-forests-climate-miyawaki.html (“The tiny forest . . . is . . . already acting quite a bit older than its actual age, which is just shy of 2. Its aspens are growing at twice the speed normally expected, with fragrant sumac and tulip trees racing to catch up. It has absorbed storm water without washing out, suppressed many weeds and stayed lush throughout last year’s drought. The little forest managed all this because of its enriched soil and density, and despite its diminutive size: 1,400 native shrubs and saplings, thriving in an area roughly the size of a basketball court.

Tiny forests have been planted across Europe, in Africa, throughout Asia and in South America, Russia and the Middle East. India has hundreds, and Japan, where it all began, has thousands. . . .

Healthy woodlands absorb carbon dioxide, clean the air and provide for wildlife. But these tiny forests promise even more. They can grow as quickly as ten times the speed of conventional tree plantations, enabling them to support more birds, animals and insects, and to sequester more carbon, while requiring no weeding or watering after the first three years, their creators said. Perhaps more important for urban areas, tiny forests can help lower temperatures in places where pavement, buildings and concrete surfaces absorb and retain heat from the sun. ‘This isn’t just a simple tree-planting method,’ said Katherine Pakradouni, a native plant horticulturist . . .. ‘This is about a whole system of ecology that supports all manner of life, both above and below ground.’

[T]iny forests . . . trace their lineage to the Japanese botanist and plant ecologist Akira Miyawaki, who in 2006 won the Blue Planet Prize, considered the environmental equivalent of a Nobel award, for his method of creating fast-growing native forests. . . .

Dr. Miyawaki’s prescription involves intense soil restoration and planting many native flora close together. Multiple layers are sown — from shrub to canopy — in a dense arrangement of about three to five plantings per square meter. The plants compete for resources as they race toward the sun, while underground bacteria and fungal communities thrive. Where a natural forest could take at least a century to mature, Miyawaki forests take just a few decades, proponents say. . . .

The [Cambridge MA] Danehy Park forest cost $18,000 for the plants and soil amendments, Mr. Putnam said, while the pocket forest company, SUGi, covered the forest creators’ consulting fees of roughly $9,500. By way of comparison, a Cambridge street tree costs $1,800. . . .

The initial density is crucial to stimulating rapid growth, said Hannah Lewis, the author of “Mini-Forest Revolution. ‘It quickly creates a canopy that shades out weeds, and shelters the microclimate underneath from wind and direct sun, she said.’”)

Shubhendu Sharma, “An engineer’s vision for tiny forests, everywhere,” Ted Talks, March 2014, https://www.ted.com/talks/shubhendu_sharma_an_engineer_s_vision_for_tiny_forests_everywhere?language=en

Tennis courts. “Tennis Court Dimensions & Size,” Harrod Sport, March 27, 2020, https://www.harrodsport.com/advice-and-guides/tennis-court-dimensions (“Tennis Court Dimensions A tennis court is 78ft (23.77m) in length. The courts used for singles matches are 27ft (8.23m) wide, while doubles courts are 36ft (10.97m) wide. The court’s service line is 21ft (6.4m) from the net. . . .

What is the total area of a tennis court? The total area of a tennis court is usually 260.87m² –the total playing area of a doubles court. A singles court, which is often marked within the doubles court has a total playing area of 195.65m². [Math – difference 65.22 – ½ = 32.61 - + 195.65 = 228.26 228.26 sq meters = 2456.970192 sq feet = 0.056404 acre

Basketball courts. M Campbell, “Diagrams of Basketball Courts,” https://www.recunlimited.com/blog/diagrams-basketball-courts/ (“Court Dimensions:

Professional NBA and College Basketball court is 94 feet (29 m) by 50 feet (15 m). [4700 square feet])

# # #

Paving Paradise

Paving Paradise at the Expense of Trees
Nicholas Johnson
The Gazette, September 26, 2023, p. A6

“They paved paradise
And put up a parking lot”

If you’re close to my age you’ll remember those lines from Joni Mitchell’s 1970 song, “Big Yellow Taxi.”

They came to me recently during my morning walk past a recently significantly expanded University of Iowa parking lot in what used to be a neighborhood of families, trees and wilderness enjoyed by all.

When it comes to the changes, as with so many other decisions, “it’s all about the money.” The rental income from a house full of students totals more than what a family can afford. And apparently somebody thought the income from 130 additional parking spaces would be well worth the loss of 30 trees (roughly four parking spaces per tree). [Photo source: Nicholas Johnson]

"They took all the trees
Put 'em in a tree museum”

And so it came to pass that, without notice to neighbors (of which I’m aware), 30 trees were sawed into pieces, dug out, carried away and replaced with cars.

Those of us living in Cedar Rapids and Iowa City, our public officials and local organizations, have long been recognized for our understanding of trees’ importance. Cedar Rapids’ well-deserved recent $6 million federal grant is evidence of national recognition of our accomplishments.

The more we continue to learn about trees, like other seeming miracles of Nature (such as Brittney Miller’s recent page one turtles story), the humbler we should become.

Trees ancestry goes back 400 million years when ferns developed a vascular system enabling water and minerals to go up from the roots to the leaves, and food to go down from the leaves to the roots. From 200 to 56 million years ago there appeared ginkgo and pine, and ultimately maple and oak.

Trees can’t talk, but apparently they can communicate with, and care for, each other, sometimes over long distances, sending warnings of threats and sharing food (with mother trees favoring their offspring). If only Congress could do as well.

During World War II there was a saying, “Don’t just stand there, do pushups or something.” Well, trees don’t “just stand there.” They are a major ally in fighting climate change, each absorbing about 350 pounds of CO2 annually.

I have to monitor the Air Quality Index. Trees improve it by trapping particulate pollution on leaves and bark.

They produce oxygen. They help cool in summer and warm in winter by as much as 30 to 40 degrees, reducing air conditioning and heating bills. They improve our physical and mental health. They can reduce flooding, capturing 5,000 gallons a year.

And for those who still think “it’s all about the money,” trees can help attract businesses and tourists, and increase your property’s value by up to 15 percent.

For now, keep your eye on the expanding “tiny forest” movement.

Clearly, more parking spaces and fewer trees are not the answer.

“Don't it always seem to go
That you don't know what you've got
Till it's gone”

Nicholas Johnson enjoys living under a large canopy of trees. Contact: mailbox@nicholasjohnson.org

SOURCES Joni Mitchell. Joni Mitchell, “Big Yellow Taxi” lyrics,” Jan. 7, 1970, https://jonimitchell.com/music/song.cfm?id=13 (“They paved paradise/And put up a parking lot/. . . They took all the trees/Put 'em in a tree museum/. . . Don't it always seem to go/That you don't know what you've got/Till it's gone”)

More rental from students than families. Karen Black, “The Role Student Housing Plays in Communities; Off-campus housing for college students has grown extensively over the last decade, and communities across the country are hoping to gain control over its spread and potential negative impact on neighborhoods and available affordable housing,” Shelterforce, Sept. 6, 2019, https://shelterforce.org/2019/09/06/the-role-student-housing-plays-in-communities/ (“For landlords, student rentals are an incredibly lucrative real estate opportunity as students pay by the room, allowing landlords to charge more per square foot as there are several roommates paying a monthly rent. As a website for real estate investors recently noted, “a home that might rent for $1,000 a month to a single family could be rented by the room for nearly twice that.” In addition students sign one-year leases so rents can be raised each year if the market allows. For neighbors, student housing can be disruptive as students keep different hours and enjoy different activities than their neighbors, such as late-night parties. And for real estate markets near college campuses, student housing can be transformative as investor capital competes with homeowners, making it so sale prices and rents increase. Local governments in college towns across the country are adopting proactive strategies to gain a measure of control over the spread of student housing and limit any negative impact on real estate markets and affordable housing stock supply near college and university campuses.”)

30 Trees, 130 parking spaces. These numbers are from my own counts and confirming re-counts.

Cedar Rapids/Iowa City awards for trees. “City of Cedar Rapids: Tree City USA Recipient,” Cedar-Rapids.org, April 19, 2023, https://www.cedar-rapids.org/news_detail_T6_R1936.php (“The City of Cedar Rapids was recently honored with the 2022 Tree City USA Award at the 32nd Annual Community Forestry Awards Luncheon in Ankeny. The award was presented by the Arbor Day Foundation and the Iowa Department of Natural Resources April 12 at the FFA Enrichment Center in Ankeny. Cedar Rapids has been a Tree City USA award winner for the past 45 years, longer than any other city in the state.

"Native Tree Restoration Initiative," Monarch Research, Marion, Iowa, "Planting Forward 2021-23 Participation Overview 092023.pdf (180 woodlands, 96 schools, 49 organizations, 5 municipalities, 4 colleges)

“Iowa City Named Tree City USA Once Again,” ICGov.org, April 23, 2023, https://www.icgov.org/Home/Components/News/News/301/390, (“Iowa City has once again been named a Tree City USA by the Arbor Day Foundation in honor of its commitment to effective urban forest management.

The Arbor Day Foundation is a million-member nonprofit conservation and education organization with the mission to inspire people to plant, nurture, and celebrate trees.

Iowa City achieved its 43rd Tree City USA recognition by meeting the program's four requirements: a tree board or department, a tree care ordinance, an annual community forestry budget of at least $2 per capita, and an Arbor Day observance and proclamation.

The City also received a Tree City USA Growth Award for demonstrating environmental improvement and an outstanding level of tree care.

Tyler Baird, Iowa City Forestry Superintendent, said: “Iowa City Forestry staff are committed to providing a healthy and sustainable urban forest for the benefit and enjoyment of all residents and visitors. The Tree City USA designation highlights this commitment to planting and caring for trees in our community.”)

Cedar Rapids federal tree grant. Marissa Payne, “In USDA’s $1.1 billion investment in tree planting, Cedar Rapids’ ReLeaf reforestation effort awarded $6 million; Iowa communities, Department of Natural Resources receive $15.7 million through Forest Service grants,” The Gazette, Sept. 15, 2023, https://www.thegazette.com/federal-government/in-usdas-1-1-billion-investment-in-tree-planting-cedar-rapids-releaf-reforestation-effort-awarde/ (“In a move to expand equitable access to trees and green spaces nationwide, U.S. Agriculture Secretary Tom Vilsack on Thursday announced an award of $6 million toward Cedar Rapids’ effort to reforest the city after the 2020 derecho toppled most of the city’s tree canopy.”)

Brittney Miller’s turtles. Brittney J. Miller, “”Turtles Have Personalities – Which Could Help Them Survive; Coe Study Shows Ornate Box Turtles Behave Differently,” The Gazette, Sept. 14, 2023, p. 1, https://www.thegazette.com/environment-nature/a-threatened-turtle-species-has-personality-knowing-that-could-help-them-survive/

Trees’ history. “A Brief History of Trees,” Trees Charlotte, April 20, 2021, https://treescharlotte.org/tree-education/a-brief-history-of-trees/ (“400 million years ago: Fossil records of the first tree-like plants appear, such as lycophytes, ferns, and horsetails. These types of plants did not have seeds yet, but were the first to have vascular systems, . . .. 200 million years ago: Evidence of the first ginkgo trees. 150 million years ago: Evidence of the first pine trees. . . . 67 million years: Evidence of the first maple trees. 56 million years ago: Evidence of the first oak trees.”

“Phloem and xylem: Difference in a plant’s vascular system, explained,” Britannica, https://www.britannica.com/video/152186/components-plant-vascular-system

Talking Trees. Richard Grant, “Do Trees Talk to Each Other? A controversial German forester says yes, and his ideas are shaking up the scientific world,” Smithsonian Magazine, March 2018, https://www.smithsonianmag.com/science-nature/the-whispering-trees-180968084/ (“I’m walking in the Eifel Mountains in western Germany, through cathedral-like groves of oak and beech, and there’s a strange unmoored feeling of entering a fairy tale. The trees have become vibrantly alive and charged with wonder. They’re communicating with one another, for starters. They’re involved in tremendous struggles and death-defying dramas. To reach enormousness, they depend on a complicated web of relationships, alliances and kinship networks.

Wise old mother trees feed their saplings with liquid sugar and warn the neighbors when danger approaches. Reckless youngsters take foolhardy risks with leaf-shedding, light-chasing and excessive drinking, and usually pay with their lives. Crown princes wait for the old monarchs to fall, so they can take their place in the full glory of sunlight. It’s all happening in the ultra-slow motion that is tree time, so that what we see is a freeze-frame of the action.

My guide here is a kind of tree whisperer. Peter Wohlleben, a German forester and author, has a rare understanding of the inner life of trees, and is able to describe it in accessible, evocative language. . . . Now, at the age of 53, he has become an unlikely publishing sensation. His book The Hidden Life of Trees: What They Feel, How They Communicate, written at his wife’s insistence, sold more than 800,000 copies in Germany, and has now hit the best-seller lists in 11 other countries, including the United States and Canada. . . .

A revolution has been taking place in the scientific understanding of trees, and Wohlleben is the first writer to convey its amazements to a general audience. The latest scientific studies . . . confirm . . .: Trees are far more alert, social, sophisticated—and even intelligent—than we thought.

[A] substantial body of scientific evidence . . . shows . . . that trees of the same species are communal, and will often form alliances with trees of other species. Forest trees have evolved to live in cooperative, interdependent relationships, maintained by communication and a collective intelligence similar to an insect colony.

Wohlleben [says], “All the trees here . . . are connected to each other through underground fungal networks. Trees share water and nutrients through the networks, and also use them to communicate. They send distress signals about drought and disease, for example, or insect attacks, and other trees alter their behavior when they receive these messages.” . . . To communicate through the network, trees send chemical, hormonal and slow-pulsing electrical signals, which scientists are just beginning to decipher. . . .

When a giraffe starts chewing acacia leaves, the tree notices the injury and emits a distress signal in the form of ethylene gas. Upon detecting this gas, neighboring acacias start pumping tannins into their leaves. In large enough quantities these compounds can sicken or even kill large herbivores.”)

Do pushups or something. Google can find no source for the saying, so I guess the default source is going to have to be “just a memory from childhood.”

Benefits of trees. “We Need Trees and here’s why . . .,” Forestry & Natural Resources, Purdue University, (no date), https://www.purdue.edu/fnr/extension/we-need-trees-and-heres-why/ (“Here are some easy ways in which urban trees and woodlots contribute to making cities more environmentally sustainable and livable:

• Trees can contribute to the increase of local food and nutrition security, providing food such as fruits and nuts for wildlife and human consumption.
• Trees play an important role in increasing urban biodiversity, providing plants and animals with a proper habitat, food and protection.
• A mature tree can absorb up to 350 lbs. of CO2 per year. As a result, trees play an important role in climate change mitigation. In cities with high levels of pollution, trees can improve air quality making cities healthier places to live in.
• Strategic placement of trees in cities can help to cool the air between 30-40o F, thus reducing the urban “heat island” effect, helping reduce extreme heat conditions in summer weather.
• Large trees are great biological filters for urban pollutants and particulate pollution. They absorb pollutant gases (such as carbon monoxide, nitrogen oxides, ozone and Sulphur oxides) and filter fine particulates such as dust, dirt, or smoke out of the air by trapping them on leaves and bark.
• Research shows that living in close proximity of urban green spaces and having access to them, can improve physical and mental health, for example by decreasing high blood pressure and stress. Also, research indicates greatly improved neo-natal health as well. This, in turn, contributes to the well-being of urban communities.
• Mature trees regulate water flow and play a key role in preventing floods and reducing the risk of sewer overflow. Stormwater management is a crucial city infrastructure issue and trees help. A mature tree, for instance, can intercept more than 5,000 gallons of water per year and without trees, every rain would contribute floods.
• Trees also help to reduce carbon emissions by helping to conserve energy. For example, the correct placement of trees around buildings can reduce the need for air conditioning by 30 percent and reduce winter heating bills by 20-50 percent.
• Planning urban landscapes with trees can increase property value, by up to 15 percent, and attract tourism and business.

“Arbor Day Foundation Announces Planting Locations for 20 Million Trees Jan. 10, 2020; After YouTube's largest-ever crowdfunding campaign raised $20 million in just 56 days, the Arbor Day Foundation is kicking off tree planting around the globe,” T&D World, Jan. 10, 2020, https://www.tdworld.com/vegetation-management/article/21120273/arbor-day-foundation-announces-planting-locations-for-20-million-trees (“T&D=Transmission and Distribution -- “Dan Lambe, president of the Arbor Day Foundation. "Now, the Arbor Day Foundation will do what we do best: ensure that 21.5 million trees are planted in the right places and at the right time." With more than 500,000 unique #TeamTrees donors from at least 200 countries, the first wave of planting was designed to ensure that every continent except Antarctica was supported.” Graphuc: #TeamTrees Thank you for helping to plant 20 million trees! Based on a U.S. Forest Service analysis, these trees will: • Remove 115,000 tons of chemical air pollution, enough gaseous pollution to fill 14,000 Goodyear blimps. • Absorb and store 1.6 million tons of carbon, the equivalent of taking 1.24 million cars off the road for a year. • Result in 1.5 billion cubic meters (400 billion gallons) of avoided water runoff, the equivalent of filling the water bottle of every person on Earth every day for a year.

[One cubic meter is 35.3147 cubic feet; 7.48052 gallons in a cubic foot = 396,258,479,000 gallons c. 400 billion gallons] Arbor Day Foundation, https://www.arborday.org

“Biden-Harris Administration announces historic funding to expand access to trees and green spaces in disadvantaged urban communities,” USDA Press Release, Newark, NJ, April 12, 2023, https://www.fs.usda.gov/news/releases/biden-harris-administration-announces-historic-funding-expand-access-trees-and-green (“Research shows that trees and green spaces improve physical and mental health outcomes and create new economic opportunities,” said USDA Undersecretary for Natural Resources and the Environment Dr. Homer Wilkes. “They also enhance community green spaces and support lasting community relationships and engagements. These funds will enable us to bring these benefits to disadvantaged communities across the nation, and to support new partnerships with a diverse array of organizations.”” “John Podesta, Senior Advisor to the President for Clean Energy Innovation and Implementation. “It’s about cleaning up the air we breathe, keeping city streets cool during sweltering summers, and creating safer, healthier neighborhoods for our kids.” “Since my days as Mayor of Newark, I have seen the transformative impact that planting trees can have for urban communities,” said Sen. Booker. “Studies have shown that trees save families money in heating and cooling costs, reduce air and water pollution, decrease the risk of respiratory illnesses like asthma, reduce flooding, and protect people from extreme heat.” “Investing in our urban forests is investing in the health and wellness of our communities,” said Forest Service Chief Randy Moore. “Trees provide numerous benefits, like improving air quality, reducing stormwater runoff, providing shade, creating safe outdoor spaces for recreation, and stimulating other kinds of investments.”)

“Throwing Shade: Exploring the Benefits of Trees,” U.S. Environmental Protection Agency, May 6, 2020, https://www.epa.gov/sciencematters/throwing-shade-exploring-benefits-trees (“Corvallis, Oregon. Impacts included reductions in four air pollutants, (O3, NO2, SO2, PM10), carbon sequestration, decreased stormwater runoff, building energy savings due to shading, and (thanks to city trees), increased real estate values.”)

Trees Forever, https://treesforever.org/ and https://treesforever.org/resources/ and https://treesforever.org/document/why-trees-matter/ (“Benefits such as energy conservation, improved air and water quality, increased property values and economic vitality, improved health and well-being, habitat improvement and more!”) (“Trees Are Our Hardest Working Residents” stormwater reduction, property value increase, energy savings, air quality improvement, CO2 reduction)

Dustin Renwick, “How one city plans to recover from losing most of its trees; Tens of thousands of trees in Cedar Rapids, Iowa, were destroyed by a devastating summer windstorm. That has meant heartache for city residents, but also opportunity to replant stronger,” National Geographic, Dec. 10, 2020, https://www.nationalgeographic.com/environment/article/how-one-city-plans-to-recover-from-losing-all-of-its-trees (80,000 trees; “Estimates of how much trees save in U.S. electricity costs range from $1 billion to $4.7 billion. The more conservative number comes from a study by Rob McDonald, lead scientist for nature-based solutions at The Nature Conservancy.” “Urban forests don’t just block sun, they also intercept rain -- it’s why the sidewalk under a sprawling hickory remains dry during a light shower. Tree roots prevent soil from moving as rainwater rushes across it, and leaves and branches keep rainfall from slamming into unprotected hillsides or impervious surfaces like parking lots and streets. When rain batters those areas, it erodes soil and often collects a mix of toxins, carrying them into streams and rivers. With so many trees gone, millions more gallons of polluted stormwater will enter the Cedar Rapids watershed.”)

Trees increase property values. “We Need Trees and here’s why . . .,” Forestry & Natural Resources, Purdue University, (no date), https://www.purdue.edu/fnr/extension/we-need-trees-and-heres-why/ (“Planning urban landscapes with trees can increase property value, by up to 15 percent, and attract tourism and business.”)

Tiny Forests. Cara Buckley, “Tiny Forests With Big Benefits; Native plants crowded onto postage-stamp-size plots have been delivering environmental benefits around the world — and, increasingly, in the U.S.,” New York Times, Aug. 26, 2023, https://www.nytimes.com/2023/08/24/climate/tiny-forests-climate-miyawaki.html (“[“Tiny forests” are] a sweeping movement that is transforming dusty highway shoulders, parking lots, schoolyards and junkyards worldwide. Tiny forests have been planted across Europe, in Africa, throughout Asia and in South America, Russia and the Middle East. India has hundreds, and Japan, where it all began, has thousands.

Now tiny forests are slowly but steadily appearing in the United States. In recent years, they’ve been planted alongside a corrections facility on the Yakama reservation in Washington, in Los Angeles’s Griffith Park and in Cambridge, where the forest is one of the first of its kind in the Northeast.”)

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Is It Hot Enough for You?

Is It Hot Enough for You?
Nicholas Johnson
The Gazette, July 18, 2023, p. A5
I’m about to reveal a new book that could save your life — or at least explain when and why we may all die.

Ever heard of the microbe “Strain 121?” No? I hadn’t either. Turns out it’s able to live in the 212- to 250-degree ocean water from underwater volcanoes.

As you’re probably aware, we Homo sapiens would be thoroughly cooked at those temperatures.

But without heat Earth would be a relatively constant 455 degrees below zero.

Like Goldilocks’ search for the perfect porridge temperature between too hot and too cold, we’ve had — until now — a temperature range that is “just right” for humans.

The mathematical odds of this? Far slimmer than your odds of filling out a perfect NCAA basketball bracket (1 in 120 billion). Especially given our furnace.

The sun is the size of 1.3 million Earths. Its core temperature is 27 million degrees; its surface 10,000 degrees. Every second it sends enough heat 93 million miles, through minus-455-degree space, to equal the heat from three to six Hiroshima-size atomic bombs.

Which brings us to CO2. Without the greenhouse gas levels we used to have our average temperature would be 4 degrees below zero. It’s the CO2’s global warming that made it “just right.”

But we now have two problems moving us from “just right” to “too hot.”

First, the CO2 that’s already there and difficult to remove without a herculean tree-planting project. And second, the increasing amounts of CO2 we’re creating from fossil fuels.

We know about skin cancer and heat stroke from too much sun and drinking water to replace sweat. But there is so much we don’t know. The role of humidity and “wet bulb” thermometers. The impact of heat on the risk of miscarriage, heart attacks, kidney disease, suicides, gun violence and children’s test scores. [Photo: A warning sign in Lake Mead National Recreation Area, February 20, 2022, advising of the danger of extreme heat in the summer months. Source: Wikimedia, Creative Commons.]

That heat has an effect on how cells function, proteins unfold, molecules move, the heart pumps, and organs respond. That 489,000 people worldwide died from extreme heat in 2019, and 850 million live in areas that had all-time record temperatures in 2022.

We built a world for ourselves filled with unarticulated assumptions. During my lifetime I can’t recall hearing or reading anyone’s speculation about, or plan for dealing with top temperatures of 130, 140 or 150 degrees — rather than 100 or, worst case, 120 degrees.

We haven’t built homes, office buildings, highways, railroads, or even wardrobes with excessive, ever-increasing heat in mind — and couldn’t afford to replace them all. We don’t have an electric grid that could support every American’s super-powerful air conditioner running day and night, pumping more heat into our urban heat islands.

So, what’s that new book I promised you? It’s a remarkably creative bit of writing blending facts with, not fiction, but true stories of individuals and families, athletic and experienced, whose planned wonderful day outdoors ended in their death from the heat. It’s Jeff Goodell’s “The Heat Will Kill You First,” published last week.

Nicholas Johnson bought his copy at a local bookstore. You can too. Contact: mailbox@nicholasjohnson.org

SOURCES Strain 121. Caroline Williams, “Extreme survival: Creatures that can take the heat,” New Scientist, Nov. 10, 2010, https://www.newscientist.com/article/mg20827861-600-extreme-survival-creatures-that-can-take-the-heat/ (“The hottest recorded temperature at which life has been able to grow is 121 °C. This record is held by a microbe called simply Strain 121, which normally lives at temperatures of around 100 °C in hydrothermal vents; it barely seemed to notice when it was heated to 121 °C in the lab, in 2003 (Science, vol 301, p 934). Even at 130 °C the bacterium was still hanging in there, but it could not replicate until the temperature dropped.” 100C = 212F; 121C= 250 (249.8)F; 130C = 266F)

“What is a hydrothermal vent? Hydrothermal vents form at locations where seawater meets magma,” National Ocean Service, National Oceanic and Atmospheric Administration, https://oceanservice.noaa.gov/facts/vents.html (“Underwater volcanoes at spreading ridges and convergent plate boundaries produce hot springs known as hydrothermal vents.”)

Coldest place. Joe Phelan, “What is the coldest place in the solar system?” Live Science, April 16, 2022, https://www.livescience.com/coldest-place-in-solar-system (“The baseline temperature of outer space is 2.7 kelvins — minus 454.81 degrees Fahrenheit, or minus 270.45 degrees Celsius — meaning it is barely above absolute zero, the point at which molecular motion stops.”)

Goldilocks. Flora Annie Steel, “Goldilocks and the Three Bears,” 1922, https://americanliterature.com/childrens-stories/goldilocks-and-the-three-bears (“First she tasted the porridge of the Great Big Bear, and that was too hot for her. Next she tasted the porridge of the Middle-sized Bear, but that was too cold for her. And then she went to the porridge of the Little Wee Bear, and tasted it, and that was neither too hot nor too cold, but just right, and she liked it so well that she ate it all up, every bit!”)

Perfect bracket odds. Daniel Wilco, “The absurd odds of a perfect NCAA bracket,” NCAA, March 16, 2023, https://www.ncaa.com/webview/news%3Abasketball-men%3Abracketiq%3A2023-03-16%3Aperfect-ncaa-bracket-absurd-odds-march-madness-dream (“Here's the TL/DR version of the odds of a perfect NCAA bracket: 1 in 9,223,372,036,854,775,808 (if you just guess or flip a coin) 1 in 120.2 billion (if you know a little something about basketball)”)

The Sun. General: “Our Sun,” Solar System Exploration; Our Galactic Neighborhood, NASA, July 12, 2023, https://solarsystem.nasa.gov/solar-system/sun/in-depth/ (“The Sun is a 4.5 billion-year-old yellow dwarf star – a hot glowing ball of hydrogen and helium – at the center of our solar system. It’s about 93 million miles (150 million kilometers) from Earth and it’s our solar system’s only star. Without the Sun’s energy, life as we know it could not exist on our home planet. . . . [Size of sun: “Many stars are much larger – but the Sun is far more massive than our home planet: it would take more than 330,000 Earths to match the mass of the Sun, and it would take 1.3 million Earths to fill the Sun's volume.”]

Heat from atomic bombs. Damian Carrington, “Global warming of oceans equivalent to an atomic bomb per second; Seas absorb 90% of climate change’s energy as new research reveals vast heating over past 150 years,” The Guardian, Jan. 7, 2019, https://www.theguardian.com/environment/2019/jan/07/global-warming-of-oceans-equivalent-to-an-atomic-bomb-per-second (“A Guardian calculation found the average heating across that 150-year period was equivalent to about 1.5 Hiroshima-size atomic bombs per second. But the heating has accelerated over that time as carbon emissions have risen, and was now the equivalent of between three and six atomic bombs per second. . . . The total heat taken up by the oceans over the past 150 years was about 1,000 times the annual energy use of the entire global population. The research has been published in the journal Proceedings of the National Academy of Sciences and combined measurements of the surface temperature of the ocean since 1871 with computer models of ocean circulation.”)

Without greenhouse gases. “The Greenhouse Effect,” British Geological Survey (BGS), undated, https://www.bgs.ac.uk/discovering-geology/climate-change/how-does-the-greenhouse-effect-work/ (“‘Greenhouse gases’ are crucial to keeping our planet at a suitable temperature for life. Without the natural greenhouse effect, the heat emitted by the Earth would simply pass outwards from the Earth’s surface into space and the Earth would have an average temperature of about -20°C.” = -4F . . . Footnote 1. “1. Enhanced Greenhouse effect 'Greenhouse gases' are actually crucial to keeping our planet at a habitable temperature, without them the Earth would be about minus 17 degrees! Anthropogenic or human release of carbon dioxide is what is contributing to an additional or enhanced greenhouse effect.” . . . The contribution that a greenhouse gas makes to the greenhouse effect depends on how much heat it absorbs, how much it re-radiates and how much of it is in the atmosphere. In descending order, the gases that contribute most to the Earth’s greenhouse effect are: water vapour (H2O) carbon dioxide (CO2) nitrous oxide(N2O) methane (CH4) ozone (O3) In terms of the amount of heat these gases can absorb and re-radiate (known as their global warming potential or GWP), CH4 is 23 times more effective and N2O is 296 times more effective than CO2. However, there is much more CO2 in the Earth’s atmosphere than there is CH4 or N2O. Not all the greenhouse gas that we emit to the atmosphere remains there indefinitely. For example, the amount of CO2 in the atmosphere and the amount of CO2 dissolved in surface waters of the oceans stay in equilibrium, because the air and water mix well at the sea surface. When we add more CO2 to the atmosphere, a proportion of it dissolves into the oceans.”)

CO2 and trees. Michael Taylor, “Global warming fast shrinking rainforest role as climate protector,” Reuters, March 4, 2020, https://www.reuters.com/article/us-global-forests-climate-change/global-warming-fast-shrinking-rainforest-role-as-climate-protector-idUSKBN20R2HD (“But the 30-year study, led by the University of Leeds and involving almost 100 institutions, showed that the intake of carbon by “intact tropical forests” peaked in the 1990s and had dropped by a third by the 2010s.

Intact forests are large areas of continuous forest with no signs of intensive human activity like agriculture or logging. They form part of the world’s roughly 5.5 billion hectares of forest.

Trees suck carbon dioxide from the air, the main greenhouse gas heating up the Earth’s climate, and store carbon, which they release when they are cut down and are burned, or rot.

Tropical forests are huge reservoirs of carbon, storing 250 billion tonnes in their trees alone - an amount equivalent to 90 years of global fossil-fuel emissions at current levels.”)

Mark Tutton, “Restoring forests could capture two-thirds of the carbon humans have added to the atmosphere,” CNN, July 5, 2019, https://www.cnn.com/2019/07/04/world/forests-capture-two-thirds-of-carbon-emissions-scn-intl/index.html (“Restoring the world’s lost forests could remove two thirds of all the planet-warming carbon that is in the atmosphere because of human activity, according to a new study.

Since the industrial revolution, humans have added around 300 billion tons of extra carbon to the atmosphere – mainly through burning fossil fuels – which is heating the planet to dangerous levels. But trees naturally remove carbon from the atmosphere, storing it above and below ground.

A new study, carried out by researchers at Swiss university ETH Zurich and published Thursday in the journal Science, has calculated that restoring degraded forests all over the world could capture about 205 billion tons of carbon in total. Global carbon emissions are currently around 10 billion tons per year.”)

Sun and skin cancer. “How does the sun cause cancer?” Worldwide Cancer Research, March 1, 2022, https://worldwidecancerresearch.org/news-opinion/2022/march/how-does-the-sun-cause-skin-cancer/ (“Over 80% of skin cancers are caused by overexposure to UV radiation. This includes UV rays from the sun, but also from sunbeds and tanning lamps. UV radiation damages DNA in your skin cells, which can accumulate over time and increase the risk of genetic mutations that cause skin cancer. The more often you get burnt, the more damage is done and the higher the risk of skin cancer. It’s also important to know that you don’t necessarily need to get a sunburn for UV rays to damage your cells.”)

Paragraph beginning, “Most of us know about skin cancer . . .” Jeff Goodell, “The Heat Will Kill You First,” 2023, pp. 18-20

Heat and the human body. (almost two pages of quotes for this one entry) Ruby Mellen and William Neff, “What extreme heat does to the human body; Climate change is making parts of the world too hot and humid to survive,” Washington Post, July 28, 2021, https://www.washingtonpost.com/world/interactive/2021/climate-change-humidity/ (“Deadly heat waves have swept the globe and will continue to because of climate change. - The trends are prompting doomsday questions: Will parts of the world soon become too hot to live in? How will we survive?

And humidity, driven in part by climate change, is increasing.

A measurement of the combination of heat and humidity is called a “wet-bulb temperature,” which is determined by wrapping a completely wet wick around the bulb of a thermometer. Scientists are using this metric to figure out which regions of the world may become too dangerous for humans.

A term we rarely hear about, the wet-bulb temperature reflects not only heat, but also how much water is in the air. The higher that number is, the harder it is for sweat to evaporate and for bodies to cool down.

At a certain threshold of heat and humidity, “it’s no longer possible to be able to sweat fast enough to prevent overheating,” said Radley Horton, a professor at Columbia University’s Lamont-Doherty Earth Observatory.

Scientists have found that Mexico and Central America, the Persian Gulf, India, Pakistan and Southeast Asia are all careening toward this threshold before the end of the century.

As the sun heats up the air, the ground, objects and people, the human body will react in an effort to cool itself.

The skin sweats. Evaporation of this water cools the body — as long as the surrounding humidity levels allow the evaporation to take place.

If the hot air is too humid, that heat exchange is blocked and the body loses its primary means of cooling itself.

The wet-bulb temperature that marks the upper limit of what the human body can handle is 95 degrees Fahrenheit (35 Celsius). But any temperatures above 86 degrees Fahrenheit (30 Celsius) can be dangerous and deadly. Horton and other scientists noted in a 2020 paper that these temperatures are occurring with increasing frequency in parts of the world. To put things in perspective, the highest wet-bulb temperature ever recorded in the Washington region, known for its muggy, unbearable summers, was 87.2 degrees (30.7 Celsius).

“Extreme humid heat overall has more than doubled in frequency since 1979,” the study’s authors wrote.

Even below these thresholds, cooling down is hard work on the body. The efforts to fight the effects of heat puts pressure on your heart and kidneys. With extreme heat, people’s organs can start to fail. If you have preexisting conditions, it’s even more likely.

As your body works to cool down, the heart works harder in an effort to pump blood up just below the surface of the skin, where it can get cooler.

The kidneys work harder to conserve your body’s water.

When your body temperature gets too high, it will ultimately cause your body’s proteins to break down, its enzymes to stop regulating your organs’ functions and your organs to start shutting down.

This is a heat stroke: Your body essentially cooks to the point where you have multi-organ failure.

“It’s very clear during a heat wave, more people do die of heat stroke,” said Zachary Schlader, an associate professor at Indiana University Bloomington who focuses on thermal stress and the human body. But even more die of heart-related conditions. “The body responds [to heat] in such a way it could make the organ vulnerable.”)

Casey Crownhart, “How hot is too hot for the human body? Climate change is bringing extreme heat and testing the limits of what people can tolerate,” MIT Technology Review, July 10, 2021, https://www.technologyreview.com/2021/07/10/1028172/climate-change-human-body-extreme-heat-survival/ (“For a study published in Nature Climate Change in 2017, Mora and his team analyzed hundreds of extreme heat events around the world to determine what combinations of heat and humidity were most likely to be deadly, and where those conditions were likely to occur in the future.

They found that while today around 30% of the world’s population is exposed to a deadly combination of heat and humidity for at least 20 days each year, that percentage will increase to nearly half by 2100, even with the most drastic reductions in greenhouse-gas emissions.

Other researchers have found that climate change is making extreme heat waves up to hundreds of times more likely and causing over a third of heat-related deaths. We’re changing our planet—what are the limits of what we can endure? . . .

When your core temperature gets too hot, everything from organs to enzymes can shut down. Extreme heat can lead to major kidney and heart problems, and even brain damage, says Liz Hanna, a former public health researcher at the Australian National University, who studies extreme heat.

Your body works to maintain its core temperature in hot environments mostly by using one powerful tool: sweat. The sweat you produce evaporates into the air, sucking heat from your skin and cooling you down. . . .

Wet-bulb temperature can estimate what your skin temperature would be if you were constantly sweating, so it’s often used to approximate how people would fare in extreme heat.

A wet-bulb temperature of 35 °C, or around 95 °F, is pretty much the absolute limit of human tolerance, says Zach Schlader, a physiologist at Indiana University Bloomington. Above that, your body won’t be able to lose heat to the environment efficiently enough to maintain its core temperature. That doesn’t mean the heat will kill you right away, but if you can’t cool down quickly, brain and organ damage will start.”)

“Heat and Health,” World Health Organization, June 1, 2018, https://www.who.int/news-room/fact-sheets/detail/climate-change-heat-and-health

Katherine Gianni & Molly O’Brian Gluck, “How Does Heat Exposure Affect The Body and Mind?; Know the heat-related illness risks for physical, mental health and how to stay safe when temperatures rise,” (Q&A with “Gregory Wellenius, Boston University professor of environmental health and director of BU’s Program on Climate and Health”) The Brink, Boston University, July 6, 2021, https://www.bu.edu/articles/2021/how-does-heat-exposure-affect-the-body-and-mind/ (“Heat doesn’t just impact the body; it also impacts the mind. . . . “Hot days can lead people to suffer from dehydration, heat exhaustion, and in extreme cases, heat stroke. But hot days are also associated with higher risk of a number of other conditions that are not typically thought to be “heat-related,” such as [kidney] problems, skin infections, and preterm birth among pregnant women. . . . moderately hot days can place vulnerable individuals at higher risk.” “a recent study in New York found that hot days were associated with higher risk of emergency room visits for substance abuse, mood and anxiety disorders, schizophrenia, and dementia. Other studies show that hot weather is linked to lower performance on standardized tests, higher risk of judgment errors, and higher risks of occupational injuries.”)

Sarah Griffiths, “Will Texas become too hot for humans? Texas is in the grip of a relentless heatwave – but how much hotter could summers get in years to come?” BBC Future, June 30, 2023, https://www.bbc.com/future/article/20230630-will-texas-become-too-hot-for-humans (“Extreme heat is currently the deadliest natural hazard in the US, with young children and adults over the age of 65 among the most vulnerable to heat-related illness and death. Analysis by The Texas Tribune found more than 275 people in Texas died from heat-related illness in 2022, which was a two-decade high, and this year's heatwave appears to be worse.

Young children, the elderly, the sick, and the poor who cannot afford technology including air-conditioning to help keep them cool are particularly vulnerable to the effects of extreme heat. High air temperatures can cause heat stroke, dehydration and affect people's cardiovascular and nervous systems. . . .

a "wet-bulb" temperature of 95F (35C) at 100% humidity, or 115F at 50% humidity is probably as hot as most humans can maintain a healthy core body temperature by sweating. Above that "critical environmental limit" our body temperature rises continuously and the risk of heat-related illnesses such as heat stroke increases. . . .

And even when they aren't life-threatening, hotter temperatures can impair cognition, motor control and affect our ability to perform everyday tasks. . . . It's well-established that warmer weather can make us more aggressive, increasing rates of violent crime and the probability of social unrest. . . . "Over the next 50 years, millions of Americans will be caught up in this churn of displacement, forced inland and northward in what will be the largest migration in our country's history," says author Jake Bittle, whose book The Great Displacement, tell stories of people forced to leave their homes due to extreme weather events.”)

Deaths from heat. Jeff Goodell, “The Heat Will Kill You First,” 2023, p. 18 (“A study in the Lancet . . . estimated that 489,000 people worldwide died from extreme heat in 2019.”)

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