volunteers

Cooling Down Urban Heat Islands

November 6, 2019 By EarthWise Leave a Comment

Researchers have known about and studied the urban heat island effect for quite some time. Since large cities began to emerge in the 19th century, it has been understood that various aspects of the urban environment lead to warmer temperatures than the surrounding countryside.

Researchers led by a group at Portland State University in Oregon have been utilizing a new way of studying the urban heat island effect. They have used citizen science volunteers in 24 cities around the world to map temperatures in the cities at ground level in great detail using mobile sensors attached to slow-moving vehicles. Previous studies have used data from satellite or stationary sensors. They have learned that the urban heat island effect is more complicated, more varied, and subtler than the earlier data indicated.

They found that there are six things that affect urban heat. Three are living — the volume of the tree canopy, the height of the tree canopy, and the ground level vegetation. Three are human-built — the volume of buildings, the difference in building heights, and the coloring of the buildings.

Buildings can have both negative and positive effects. Tall buildings that cast shade actually lower relative afternoon temperatures, while densely packed shorter buildings, like the big-box stores in suburban areas, lead to hotter afternoon temperatures. The studies show that increasing the difference in building heights in an area creates more air circulation, which has a cooling effect.

The study also showed that urban heat is a social justice issue. Lower-income neighborhoods largely barren of trees have considerably higher temperatures than more affluent, tree-shaded areas.

Such detailed research can be used to guide decisions in urban planning with regard to trees, building heights, and the color and type of surfaces in our urban spaces.

**********

Web Links

Can We Turn Down the Temperature on Urban Heat Islands?

Photo, posted July 21, 2009, courtesy of Daniel Dionne via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cleaning Up Mount Everest

May 31, 2019 By EarthWise Leave a Comment

Mount Everest is the highest mountain above sea level with an elevation over 29,000 feet. As such, it is a prime attraction for mountain climbers seeking that ultimate achievement. The summit was first reached in 1953 and for a long time, only major expeditions by the best mountaineers sought to repeat the feat.

In recent years, climbing Everest has become much more common. In fact, since 1953, more than 4,000 people have reached the summit of the world’s highest mountain. A record 807 accomplished the feat last year alone. Thousands more visit lower elevations.

But climbing Everest is neither safe nor easy. Ice and snow, powerful winds, and generally harsh conditions make Everest a treacherous place. Over the decades, hundreds of climbers have died on its slopes and many of their bodies are still up there. Apart from human remains, there are decades worth of garbage left behind by hikers and tourists.

The government of Nepal has mounted an ambitious project to clean up the refuse on Mount Everest. In just the first two weeks, volunteers removed more than three tons of trash from the mountain. Among the rubbish removed from Everest are tents, climbing equipment, bottles, cans, empty oxygen containers, and human waste. They also discovered the bodies of four climbers that had emerged from melting snow and ice.

Helicopters carried a third of the garbage to Kathmandu for recycling. The rest was taken to a local district for disposal in landfills. The initial work started at Everest’s base camp. They are next moving to sites higher on the mountain. They hope to remove at least 10 tons of trash this year.

Nepal would like to make the world’s tallest mountain clean.

**********

Web Links

Volunteers Remove 3 Tons of Trash From Mount Everest in Two Weeks

Photo, posted May 23, 2012, courtesy of Gunther Hagleitner via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saved By The Trees

February 1, 2019 By EarthWise Leave a Comment

The island of Kokota, part of the Zanzibar Archipelago off the coast of Tanzania, is tiny – only one square kilometer and home to just 500 people. For centuries, its residents subsisted by harvesting the islet’s natural resources, including its trees.

By the early 21st century, the deforestation had become unsustainable and the islanders faced a crisis. Fisheries were depleted, and rivers ran dry. The changing climate brought rising sea levels, more erratic rainfall, and coral bleaching in the surrounding waters. The situation looked hopeless.

But in recent years, the island has come back from the brink of ruin. Reforestation efforts began in 2008 on the larger island of Pemba and on Kokota itself, led by a Pemba local and a Canadian tree planter who formed the non-profit Community Forests International. Since then, nearly 2 million trees have been planted on the two islands. Enthusiastic volunteers on Kokota usually help plant trees during the rainy season, when water is plentiful.

Community Forests International, along with spearheading the tree planting effort, also built Kokota’s first school, and installed rainwater storage tanks for the community.

The conservation group is now devising ways for Kokota to make more money by diversifying its agriculture with crops that grow well in its climate including spices like cloves, cinnamon, and nutmeg. They are also helping locals to grow more and different vegetables in their gardens.

Small, poor communities are often the most vulnerable to the effects of climate change, such as drought, powerful storms, and depleted fisheries. Tiny Kokota provides an example of an environmental comeback. Fighting climate change requires economic solutions along with environmental solutions. For this one tiny island, it appears to have been saved by the trees.

**********

Web Links

This island was on the brink of disaster. Then, they planted thousands of trees.

Photo, posted July 18, 2015, courtesy of Marco Zanferrari via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saving The Siberian Tiger

March 13, 2018 By EarthWise Leave a Comment

The northeastern part of China, wedged between North Korea to the south and Russia to the northeast, is home to two highly endangered big cats: the Siberian tiger and the Amur leopard. Siberian tigers, which can weigh over 600 pounds and grow to more than 10 feet in length, now number only about 500 in the wild, mostly in Russia. Amur leopards, weighing more than 100 pounds and growing to more than four feet in length, number only about 80 in the wild. While both species are right on the edge of extinction, both are slowly rebounding.