The Swedish environmental activist Greta Thunberg (holding sign) marches in a 2019 protest organized by students. As a teenager, Thunberg became known for her boldness in confronting adult politicians for their inaction on climate change due to global warming.
Credit: © Alexandros Michailidis, Shutterstock

This Saturday, April 22, is Earth Day, an annual observance to increase public awareness of environmental issues. Each year on Earth Day, millions of people throughout the world gather to clean up litter, protest threats to the environment, and celebrate progress in reducing pollution.

Earth Day began in the United States. In 1969, the U.S. Senator Gaylord A. Nelson suggested that a day of environmental education be held on college campuses. The following year, the lawyer and environmentalist Denis Hayes, then a recent graduate of Stanford University, led hundreds of students in planning and organizing the observance of Earth Day on April 22, 1970. About 20 million people participated in this celebration.

The observance of Earth Day in 1970 helped alert people to the dangers of pollution and stimulated a new environmental movement. That same year, Congress created the Environmental Protection Agency to set and enforce pollution standards. Congress also passed the Clean Air Act of 1970, which limited the amount of air pollution that cars, utilities, and industries could release. Other new environmental laws soon followed.

One modern champion for the environment is the Swedish activist Greta Thunberg. She has worked to convince politicians to take action against climate change due to global warming. Global warming is an observed increase in Earth’s average surface temperature. As a teenager, Thunberg became known for her boldness in confronting adult politicians for their inaction on climate change. She has called upon leaders to reduce emissions of greenhouse gases, mainly carbon dioxide. Such gases trap heat in the atmosphere, warming the planet’s surface.

Thunberg was born in Stockholm, Sweden, on Jan. 3, 2003. She was diagnosed with autism spectrum disorder at a young age. As a child, she showed an interest in environmental issues. She convinced her family to reduce their carbon footprint by becoming vegan and giving up air travel. Carbon footprint is a measure of the greenhouse gas emissions associated with human activities.

In 2018, at the age of 15, Thunberg protested for action on climate change outside the Swedish parliament, inspiring other student protesters. Together, they organized school strikes to demand action on climate change. In August 2019, Thunberg sailed across the Atlantic Ocean from Plymouth, in the United Kingdom, to New York City, in the United States, on a “carbon neutral” voyage. Thunberg sailed aboard a yacht that got its electric power from solar panels and underwater turbines. While in the United States, she addressed the United Nations as part of its Climate Action Summit. During her speech, she announced that she and a group of other children were filing a lawsuit against five nations not on track to meet their emission-reduction targets under the Paris Agreement. The Paris Agreement is a global treaty designed to fight global warming.

Thunberg is the author of several books on climate change activism. No One Is Too Small to Make a Difference (2019) is a collection of Thunberg’s speeches. Our House Is on Fire (2020), a memoir by Thunberg and her family, tells how Thunberg’s personal struggles led her to become an activist. Thunberg’s best seller The Climate Book (2023) explains how the climate is changing and calls on society to adopt effective strategies to slow climate change.

August 10, 2017

In June 2017, the state of California classified glyphosate, the most widely used herbicidal chemical in the world, as a known carcinogen (cancer-causing substance). In the early 1970’s, organic chemist John E. Franz discovered the plant-killing chemical compound while working for the Monsanto Company, a leading chemical maker in the United States. Glyphosate was patented in 1971, and in 1974 it hit stores as the herbicide Roundup, which became a top-selling Monsanto product.

A farmer sprays herbicide on a soybean field. The safety of herbicide use has come under sharp scrutiny in recent months. Credit: © Shutterstock

In the beginning, glyphosate was used only to remove weeds from gardens and other small-scale plantings. Glyphosate is a nonselective herbicide, meaning that it kills most any plant it touches. Its broad toxicity meant that farmers could not use it to kill weeds in their fields without also killing their crops. In the 1990’s, however, Monsanto began altering the genes of crop plants to resist the effects of glyphosate. Worldwide Roundup sales then skyrocketed, as did sales for Monsanto’s genetically modified seeds. Today, glyphosate is the most-used agricultural chemical in the world. Each year, hundreds of millions of pounds of the chemical are applied to cultivated land in the United States alone.

Glyphosate’s widespread use led to concerns regarding its safety. People worried about the chemical’s ability to degrade native plant communities and wondered if it might harm pollinators (such as bees) and other ecological keystone species. People also worried about humans eating crops treated with glyphosate.

In order to determine the consequences of human consumption of the herbicide, scientists tested glyphosate on animals. The scientists looked for harmful reproductive, developmental, or carcinogenic results. Some tests found little or no harmful effects, but others suggested a greater risk potential from long-term exposure. Scientists then determined that further study was needed. In March 2015, the World Health Organization’s International Agency for Research on Cancer (IARC) stated that glyphosate is “probably carcinogenic to humans.” Since then, many people with cancer have sued Monsanto, claiming that extensive use of Roundup had caused their illnesses.

In response, Monsanto called attention to the research that demonstrated glyphosate’s safe qualities. The company steadfastly adheres to the claim that the weedkiller does not cause cancer. Roundup is a key product for Monsanto, and a drop in sales could be disastrous for the company. Since the IARC warning in 2015, Monsanto has been petitioning U.S. Environmental Protection Agency (EPA) officials to declare Roundup safe once and for all.

In labeling glyphosate a carcinogen, California’s Office of Environmental Health Hazard Assessment resisted pressure from current EPA head Scott Pruitt. Pruitt, an appointee of President Donald Trump, has pushed to erase or reverse many EPA regulations. In June 2017—the same month as California’s glyphosate listing—Pruitt reversed a proposed ban on chlorpyrifos, a widely used pesticide that health studies showed can harm children’s brains.

And now, in August, a new herbicide crisis has been caused by dicamba, a newer weedkiller in the Monsanto product XtendiMax. Like glyphosate, dicamba was produced along with plants modified to withstand its herbicidal effects. However, clouds of dicamba—after being sprayed on modified crops—have drifted over unmodified crops and gardens nearby, severely damaging or destroying the plants.

August 11, 2015

People kayak in the Animas River near Durango, Colorado, on August 6, in water colored bright orange from a spill caused by the U.S. Environmental Protection Agency. Credit: © Jerry McBride, The Durango Herald/AP Imagesd

Today’s stories are environmental in nature—about spills, disasters, and cleanups. In the United States, cleanup continues on a toxic spill accidentally unleashed  by the U.S. Environmental Protection Agency (EPA). Last Wednesday, August 5, as the EPA was inspecting an abandoned mine in Colorado, workers using heavy machinery breached a wall holding back polluted water. The breach allowed 3 million gallons (11 million liters) of toxic water to pour into Cement Creek and from there into the Animas River. The polluted water carries many heavy metals (metals that have a specific gravity higher than 5.0), including iron, zinc, and copper. The spill turned the river orange and made its water unusable for drinking and farming. Most of the visible pollution has moved out of the Animas River, but sediments in the river bed will need to be tested for some time. The spill has now reached the San Juan River in New Mexico and has traveled into southern Utah. Local residents are angry that the group charged with preventing pollution had caused a spill that could affect their livelihoods and well-being.

Meanwhile, in Japan, the nation has lifted a ban on nuclear power and restarted a nuclear reactor today on the island of Kyushu. The meltdowns of nuclear reactors at Fukushima after an earthquake and tsunami in 2011 caused the government to close down most reactors in Japan by 2013. People evacuated from the area of Fukushima have still not been able to return to their homes. The cleanup of the heavily contaminated area has been painfully slow. Evacuees have been living in temporary housing and receiving a small monthly payment since the disaster. The government expects the cleanup around the Fukushima site to be completed by 2017.

New safety regulations and inspections for nuclear power plants have been put into effect since the Fukushima disaster. Japan has to import nearly all of its fossil fuels, however, and Japanese Prime Minister Shinzo Abe wants to restart Japan’s nuclear power program. Many Japanese citizens are opposed to resuming use of nuclear power. Japan sits on an area prone to earthquakes, and the lax planning and regulation highlighted in 2011 has shaken the faith of the people of Japan in nuclear power. With electricity costs in Japan up 20 percent since 2011, however, Prime Minister Abe’s goal is to have one-fifth of Japan’s electricity provided by nuclear power by 2030. 

On March 11, 2011, a 9.0-magnitude earthquake occurred off Honshu, Japan’s largest island. The earthquake caused a tsunami (series of powerful ocean waves) that caused massive destruction on land and killed thousands of people. The disaster also sparked emergencies at several nuclear power plants, most notably at the Fukushima Daiichi Nuclear Power Station. (World Book map)

June 2, 2014

In a major effort to curb global warming, the Environmental Protection Agency (EPA) today unveiled proposed rules that would significantly cut carbon pollution from United States electric power plants. The rules would mandate the first nationwide reduction in carbon emissions–30 percent over 2005 levels by 2030. Currently, about 38 percent of yearly U.S. carbon emissions–some 551 million short tons (500 million metric tons)–comes from power plants, particularly those fueled by coal. According to EPA estimates, a 30-percent reduction in carbon pollution from power plants would equal the carbon emitted by two-thirds of all cars and trucks in the United States. However, energy experts noted that more than 38 billion tons (35 billion metric tons) of carbon dioxide was  emitted worldwide in 2012.

EPA Administrator Gina McCarthy said that acting on climate change was a “moral obligation.” Carbon pollution, she said, “supercharges risks not just to our health, but to our communities, our economy, and our way of life. “The administration of President Barack Obama has been under continuing pressure from environmental groups to take significant action to reduce carbon emissions since the administration failed to get a climate change bill through Congress during the president’s first term in office.

Proposed rules from the Obama administration aim to boost the production of electric power from solar farms and other renewable energy plants in order to reduce carbon emissions. (© PhotoDisc/Getty Images)

The rules face a year-long period of public comment as well as fierce legal battles from business and industry groups and political opposition in Congress and some state legislatures. Opponents of the rules have argued that they will boost electric power costs for consumers and increase business costs. The EPA estimates that the rules will cost $7.3 billion to $8.8 billion annually but will lead to economic benefits of $55 billion to $93 billion over the life of the rule. The agency also predicted that the rules will prevent 2,700 to 6,600 premature deaths and 140,000 to 150,000 asthma attacks.

Once the rules are finalized in 2015, states would have until June 2016 to submit rules for ensuring that power plants within their borders meet the emissions cuts. EPA officials stressed that coal-fired plants need not be shut down immediately. Instead, states could install new wind, solar, natural gas, or nuclear units or upgrade pollution and efficiency technology in existing plants. They could also start or join state or regional “cap and trade” programs. Under under such programs, government sets an overall limit on carbon emissions, and then states meet these targets by allowing businesses to buy and sell pollution credits. According to the EPA, even if states meet the pollution-reduction targets, about 30 percent of U.S. electric power would come from coal, compared with 40 percent today.

Additional World Book articles:

• Air pollution
• Fossil fuels
• Greenhouse effect

April 30, 2014

The U.S. Supreme Court, in a 6-to-2 decision, upheld a 2011 rule by the Environmental Protection Agency (EPA) that would limit certain kinds of polluting air emissions that cross state lines. The ruling means that such industries as coal-fired electric power plants will likely be forced to switch to cleaner-burning fuels, such as natural gas.

Scientists have long known that wind, under certain circumstances, carries sulfur dioxide and nitrogen oxide from power plants for long distances. These pollutants react with other substances to form smog and soot that can cause respiratory illnesses and other disease. Writing for the majority, Justice Ruth Bader Ginsburg acknowledged the complexity of the problem before the EPA. “In crafting a solution to the problem of interstate air pollution, regulators [that is, the EPA] must account for the vagaries of the wind,” she noted. “Most upwind states contribute to pollution to multiple downwind states in varying amounts.”

A tug of war between the EPA and smokestack industries over drifting air pollution has been going on for decades. In 2002, the administration of then-President George W. Bush instructed the EPA to adopt new rules overturning a provision of the Clean Air Act of 1970 that required companies to adopt the best available pollution controls when major sources of pollution–such as coal-fired electric plants and refineries–are upgraded or enlarged. The provision was reinstated by the administration of President Barack Obama. Texas and 13 other states and power companies filed a lawsuit challenging its reinstatement, and a federal appeals court ruled in their favor in 2012.

Most coal mined in the United States is used to fuel electric power plants. Domestic coal is also shipped to China, where it contributes to air pollution that drifts across the Pacific to North America. (c) Grapes/Michaud, Photo Researchers.

Legal experts characterize yesterday’s court decision as an important victory for President Obama in his effort to reduce power plant pollution in 27 Midwestern and Appalachian states. EPA Administrator Gina McCarthy called the ruling “a resounding victory for public health and a key component of EPA’s efforts to make sure all Americans have clean air to breathe.”

Two of the court’s more conservative justices, Antonin Scalia and Clarence Thomas, dissented. Justice Samuel Alito recused himself from the consideration of the case.

Additional World Book articles:

• Acid rain
• Environmental pollution 2002 (a Back in Time article)
• Environmental pollution 2011 (a Back in Time article)

October 22, 2013

Air pollution in the northeast Chinese city of Harbin was literally off the chart yesterday, forcing the closure of schools, paralyzing traffic, and shutting down the airport. In parts of the city, visibility was near zero. “You can’t see your own fingers in front of you,” declared the city’s official news site.

Coal-burning plants and factories, which are common in China, produce sulfur dioxide, an air pollutant that causes acid rain and produces dangerous particulate matter in the atmosphere (© age fotostock/SuperStock).

The Harbin government reported an air quality index (AQI) score of “above 500″; 500 is the upper limit on scales used by both the Chinese government and the U.S. Environmental Protection Agency (EPA). By comparison, the AQI score in New York City yesterday was 41. The EPA labels any reading between 301 and 500 as “hazardous.” The standards set by the World Health Organization characterizes a score above 500 to be more than 20 times the level of particulate matter in the air deemed safe.

The China News service reported that yesterday’s PM2.5 (particulate matter with a diameter of 2.5 micrometers) measurement in Harbin topped 1,000 micrograms per cubic meter. This surpassed the peak of 900 in Beijing in January in what became known as that city’s “air-pocalypse.” Health experts note that particles at a level of PM2.5 are particularly dangerous because the matter is small enough to penetrate deep into the lungs and enter the bloodstream.

The Harbin weather bureau blamed the pollution on a lack of wind; local farmers burning corn stalks after the harvest; vehicular emissions; and the firing up of the municipal central heating system—coal-burning boilers that provide hot-water heat to the entire city of 3.5 million. China remains heavily dependent on coal. Fully 68.4 percent of China’s energy usage is from coal, much of it high sulfur-content coal. When coal is burned, its sulfur content combines with oxygen to form sulfur dioxides. Sulfur dioxide is a pollutant gas that contributes to the production of acid rain and causes significant health problems, particularly through its role in forming particulates.

Additional World Book articles:

• The Case for Renewables (a special report)
• China 2012 (a Back in Time article)

April 22, 2013

An interactive video display of people, animals, and places around the world that are directly affected or threatened by climate change will be shown at thousands of places worldwide today as part of the 43rd celebration of Earth Day. The display, which is also available online at  EarthDay.org, includes images of people working to combat climate change and environmental pollution.

Earth Day is an annual observance, held on April 22, to increase public awareness of environmental issues. Each year on and around Earth Day, hundreds of millions of people throughout the world gather to clean up litter, to protest threats to the environment, and to celebrate progress in reducing pollution. Many events are coordinated by the Earth Day Network (EDN), which chose “The Face of Climate Change” as the theme for this year’s event. Headquartered in Washington, D.C.,  the EDN “promotes year-round environmental citizenship and action, worldwide.” According to the EDN, about 1 billion people in 192 countries were expected in participate in environmental activities to celebrate Earth Day 2013.

People celebrate Earth Day in Washington, D.C. (AP/Wide World)

Earth Day began in the United States. In 1969, U.S. Senator Gaylord A. Nelson (D., Wisconsin) suggested that a day of environmental education be held on college campuses. The following year, the lawyer and environmentalist Denis Hayes, then a recent graduate of Stanford University, led hundreds of students in planning and organizing the observance of Earth Day on April 22, 1970. About 20 million people participated in this celebration. By 1990, participation had increased to an estimated 200 million people in 141 countries.

The observance of Earth Day in 1970 helped alert people to the dangers of pollution and stimulated a new environmental movement. That same year, Congress created the Environmental Protection Agency to set and enforce pollution standards. Congress also passed the Clean Air Act of 1970, which limited the amount of air pollution that cars, utilities, and industries could release. Other new environmental laws soon followed.

Additional World Book articles:

• Conservation
• Global warming
• Congress of the United States 1970 (a Back in Time article)
• Polluting the Earth (a special report)

January 22, 2013

The Supreme Court of the United States confirmed today that the Environmental Protection Agency (EPA) has the authority to set air quality standards. The court’s decided, without comment, not to hear an appeal by the Asarco Corporation of a July 2012 decision by the Washington, D.C., Circuit Court of Appeals that upheld the EPA’s new national ambient air quality standard for sulfur dioxide. Asarco, a unit of Grupo Mexico SAB, operates one of the three main copper smelters in the United States. By refusing to hear the appeal, the court upheld the lower court’s decision that the EPA has the authority under the Clean Air Act to adopt standards that are necessary to protect public health.

The Supreme Court has ruled that the Environmental Protection Agency has the authority to set air quality standards. (© Joe Sohm, Photo Researchers)

Exposure to sulfur dioxide, which typically is produced by the burning of fossil fuel at electric power generating plants and other industrial facilities, has been linked to respiratory illnesses. The 2010 EPA rule limits sulfur dioxide in the air to 75 parts per billion over a one-hour period. Asarco claims that it will cost as much $1.5 billion to bring its Hayden, Arizona, smelter into compliance with the 2010 rule.

Additional World Book articles:

• Air pollution
• Environmental pollution
• Environmental pollution 2010 (a Back in Time article)

United States President Barack Obama has halted plans by the Environmental Protection Agency (EPA) to tighten federal regulations on ground-level ozone emissions. Ozone is the main ingredient in smog, a powerful lung irritant that can cause asthma among other ailments. He cited the potential economic burden on a weakened economy. Estimates of the cost of the new regulations ranged from $19 billion to $90 billion a year by 2020, depending on how strictly they were enforced.

Environmental groups and former Vice President Al Gore criticized the decision and accused the president of buckling under to members of the Republican Party in Congress. Many business interests and Congressional Republicans  had lobbied strenuously against the proposed standards. President Obama noted that the standards would be reviewed in 2013 as required by the Clean Air Act.

Additional World Book articles:

• Air pollution
• Environmental pollution (Air pollution)
• Environmental Defense Fund
• Greenpeace