October 4, 2019

Since the beginning of winter in South America (summer in the Northern Hemisphere), more than 200,000 wildfires have struck the Amazon rain forest of Brazil, Bolivia, Paraguay, Peru, and Venezuela. Some 30 million acres (12 million hectares) of wilderness have been lost in the fires, causing incalculable damage to the environment. The unusually severe fire season was blamed on winds and high temperatures as well as the ancestral practice of chaqueo (slash-and-burn farming). But many fires were thought to have been illegally set to clear land for large corporate agriculture, logging, and mining interests. Blame also fell on lax policing and the weakening of the environmental protection system in Brazil, where most of the fires occurred.

On Aug. 27, 2019, smoke rises above charred trees in the Amazon rain forest of northern Brazil. Credit: © Joao Laet, AFP/Getty Images

Forest fires are common in the Amazon during the dry season, from July to October. The fires are sometimes caused naturally by lightning strikes and exacerbated by drought, but most of the recent fires were probably started by people wanting to clear the land for other uses. There has been a vast increase in large, intense, and persistent fires along major roads in the Amazon, for example, something inconsistent with the randomness of lighting strikes. Climate change too is making the fires worse, as dry seasons in the Amazon become ever dryer, hotter, and longer.

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The Amazon rain forest covers much of northern South America. About two-thirds of the rain forest lies in Brazil. Credit: WORLD BOOK map

The fires (and the fire starters) have received divided attention in the Palácio do Planalto, the official workplace of the president of Brazil in Brasília, the capital. There, President Jair Bolsonaro has decreased environmental protections since taking office in January 2019, allowing an increase in deforestation—both legal and illegal, and always a problem—in the Amazon. Bolsonaro too has refused much international aid to help fight the fires, which continue to burn and destroy large portions of the rain forest. Bolsonaro eventually deployed some 44,000 soldiers to help the understaffed firefighters in the rain forest, and he agreed to coordinate firefighting efforts with other Amazonian countries. At the end of August, after the fires had raged for months, Bolsonaro also announced a 60-day ban on the legal setting of fires to clear land.

Deforestation results in the loss of vast areas of tropical rain forest each year. This photograph shows an area of the Amazon rain forest in Brazil that has been destroyed as part of slash-and-burn agriculture. In this method, farmers cut down trees and burn them. The ashes enrich the soil for only a brief period before the nutrients are depleted. The farmers then clear another area of forest. Credit: © Julio Etchart, Alamy Images

All seven Brazilian states that include parts of the Amazon have experienced sharp increases in fire activity in 2019. Numerous wildfires are also consuming alarming amounts of rain forest in the Amazonian regions of Bolivia, Paraguay, Peru, and Venezuela. The massive number of wildfires has greatly increased emissions of toxic carbon monoxide and the greenhouse gas carbon dioxide, a leading contributor to global warming. Smoke from the fires has obscured skies and aggravated such health problems as asthma, bronchitis, and chronic obstructive pulmonary disease (COPD) in people throughout the region.

August 5, 2019

Last week, on July 29, in the northeastern African nation of Ethiopia, citizens worked with conservation groups, business leaders, and the government to plant more than 350 million trees in a single day. Part of Ethiopia’s Green Legacy Initiative to combat deforestation and climate change, the highly organized event resulted in the planting of 353,633,660 seedlings in just 12 hours. Believed to be a world record, the number far exceeded the original goal of planting 200 million trees in one day. The Green Legacy Initiative hopes to brighten the ecological future of a nation prone to such climate-related problems as drought, famine, and soil erosion.

Prime Minister Abiy Ahmed plants one of more than 350 million trees planted in Ethiopia on July 29, 2019. Credit: Office of the Prime Minister

For the record tree-planting day, many schools and government offices were closed to allow more people to participate. Ethiopian Prime Minister Abiy Ahmed joined in the effort, planting trees in the capital city of Addis Ababa. The tree-planting drive targeted areas that have been stripped of forests over the years, and the types of new trees varied from region to region. The United Nations estimates that just 4 percent of Ethiopia is currently covered by forest, down from about 30 percent in 1900. Ethiopia’s ever-growing population, the need for more farmland, unsustainable forest use, and climate change are cited as the major causes for the nation’s drastic deforestation.

Illinois Senator (and future United States President) Barack Obama plants a tree in Uhuru Park in Nairobi, Kenya, with environmental activist and Nobel Peace Prize winner Wangari Muta Maathai in 2006. Every tree planted helps counteract the effects of climate change. Credit: © Green Belt Movement

The Green Legacy Initiative, launched in May 2019, aims to help reverse Ethiopia’s environmental decline by providing tree seedlings, encouraging tree-planting groups, and asking every citizen to plant at least 40 trees by the end of October. (The seedlings have a better chance of surviving in Ethiopia during the wetter months from May to October.) With a population of about 114 million people, this puts the initiative’s goal at more than 4 billion newly planted trees. More than 2.6 billion trees have been planted so far. Aside from ordinary counting methods, the Ethiopian government is using satellites and special computer software to keep track of the immense number of planted seedlings. The Green Legacy Initiative is also cleaning waterways and making agriculture more sustainable.

The planting of carbon dioxide-absorbing trees—along with recycling and reducing the use of plastics, fossil fuels, and other environmentally damaging materials—is a highly effective way to counteract the effects of global warming and climate change. India set the previous world record for the most trees planted in one day (50 million) on July 11, 2016.

March 15, 2012

The area covered by trees in many United States cities is declining, reports the U.S. Forest Service, and that loss of trees–as many as 4 million annually–translates into an astronomical loss in energy efficiency. According to the Forest Service, urban trees greatly decrease heating and cooling costs, by as much as $2,500 over the lifespan of a mature tree; improve air and water quality; and help control water drainage and erosion. The Forest Service calculates that the financial loss of an urban tree is, thus, three times greater that the cost of maintaining it.

Forest Service researchers David Nowak and Eric Greenfield arrived at their conclusion by comparing aerial photographs of 20 urban areas from the years 2002 to 2010 and evaluating the differences in the canopy coverage. They found that the tree cover in 17 out of the 20 cities had declined. New Orleans, Louisiana, had the largest decrease. (The research suggests that much of the tree loss there was a result of Hurricane Katrina in 2005.) Only one of the 20 cities–Syracuse, New York–showed an increase in the amount of tree cover.

Many urban trees are lost to the artifically made objects in a designed landscape. This is known as “impervious cover,” which includes rooftops and pavement–streets, sidewalks, and parking lots.

Trees across North America are under attack by a number of different diseases and pests. Urban trees are especially threatened by the emerald ash borer, the Japanese beetle, and a number of fungal diseases, including the Dutch elm disease.

Ginkgo trees are popular for city plantings because they are largely resistant to air pollution as well as various tree diseases. (Atoz)

Tree-planting programs in many cities have helped to slow tree loss but have not been able to reverse the larger trend. In an effort to make city planning more tree-conscious, the Forest Service is providing cities with a free software program entitled i-Tree Canopy. The program lets users analyze changes in an area’s tree coverage by pairing aerial photographs from different time periods. U.S. Forest Service Chief Tom Tidwell hopes the tool will help communities plant and maintain trees more effectively.

Additional World Book articles:

• Conservation
• Green building
• Ecology
• Trees Under Threat (a special report)