99 Fun Facts About Earth Day

In what year was the first Earth Day celebrated?

The first Earth Day was held on April 22, 1970, with demonstrations at thousands of colleges and schools across the United States; it is widely credited with launching the modern environmental movement.

Which US senator from Wisconsin is credited with founding Earth Day?

Gaylord Nelson is said to have been spurred by a vast 1969 oil slick he saw from an airplane; he hired 25-year-old Denis Hayes to turn the idea into a national event.

Which U.S. federal body began operating in December of the same year as the first Earth Day?

The Environmental Protection Agency opened on December 2, 1970, pulling pollution programs scattered across several federal departments into one agency under William Ruckelshaus.

What date is Earth Day celebrated each year?

Earth Day falls on April 22; organizers wanted maximum college turnout, so they picked a date between spring break and final exams. Peace activist John McConnell had separately proposed marking the March equinox.

Approximately how many Americans took part in the first Earth Day?

About 20 million Americans took part, roughly one in ten at the time; what had been pitched as a campus event filled streets, parks and auditoriums from coast to coast.

Which landmark environmental law did the U.S. Congress pass in the same year as the first Earth Day?

The Clean Air Act of 1970 ordered a 90% cut in pollution from new cars within five years, which is why catalytic converters became standard on American models in 1975.

Rachel Carson's 1962 book 'Silent Spring' focused on the dangers of what?

Silent Spring documented how pesticides such as DDT poisoned birds and other wildlife; chemical companies attacked the book, but it swayed public opinion and led to a 1972 U.S. ban on agricultural use of DDT.

In what year did Earth Day go global, with events in over 140 countries?

In 1990 Denis Hayes led a campaign that took Earth Day to 141 countries; some 200 million people took part, giving recycling a huge boost and paving the way for the 1992 Earth Summit in Rio de Janeiro.

Which oil spill in 1969 is often cited as a catalyst for the first Earth Day?

Union Oil's Platform A blew out six miles off Santa Barbara, California, in January 1969, killing thousands of seabirds; a year on, locals marked the date as Environmental Rights Day.

Which U.S. president vetoed the Clean Water Act in 1972, only for Congress to override him?

Richard Nixon vetoed the 1972 Clean Water Act over its $24 billion cost, not its goals; Congress overrode him the next day, and he then impounded funds he considered unjustifiable.

Which 1968 photograph, taken from lunar orbit by Apollo 8's Bill Anders, has been called the most influential environmental picture ever taken?

Earthrise showed a small blue planet above a dead grey horizon on Christmas Eve 1968; less than two years later, millions of Americans turned out for the first Earth Day.

Which climate accord opened for signing on Earth Day 2016?

The Paris Agreement, adopted the previous December, drew 175 signatures at the UN on that first day; enough countries then ratified for it to take force that November.

Which term covers all the greenhouse gases that a person, product or activity adds to the air?

Carbon footprint calculators were popularised by an advertising campaign from the oil company BP in the mid-2000s, which put the spotlight on personal choices rather than producers.

Which global movement grew out of Greta Thunberg's solo school strike outside Sweden's parliament?

Fridays for Future took its name from the weekly strikes she went on to hold; thirteen months after she first sat down alone, its protests drew roughly four million people in a single day.

What is the 'greenhouse effect'?

Heat-trapping gases keeping a planet warm are no bad thing in themselves: without them Earth's average surface would sit well below freezing, at about minus 18°C instead of roughly 14°C.

Which layer of Earth's atmosphere contains the ozone layer that protects us from UV radiation?

The ozone layer sits in the stratosphere, roughly 15 to 35 kilometres up; the ultraviolet it soaks up heats the air, which is why the stratosphere grows warmer with height.

The Montreal Protocol, signed in 1987, phased out which class of chemicals?

Chlorofluorocarbons from spray cans and fridges were thinning the ozone shield; the treaty became the first ratified by every UN member, and the layer should recover by the 2060s.

Which graph, named for the chemist who began tracking CO2 on Hawaii's Mauna Loa in 1958, shows its steady climb ever since?

The Keeling Curve climbs in a sawtooth: each northern summer growing plants pull CO2 out of the air, and each winter decay hands it back, a little higher every year.

Which gas from livestock and rice paddies has about 80 times CO2's warming power over 20 years?

Methane breaks down within about a decade, so its punch is front-loaded: measured over a century, its edge over CO2 shrinks to roughly 30 times.

What does 'net zero' mean in the context of climate goals?

Emissions balanced by an equal amount removed, whether by forests or by machines, is the goal; climate models suggest warming largely stops once the world gets there.

The three chasing arrows of the universal recycling symbol are folded into what mathematical shape?

The three arrows form a Möbius strip, a one-sided loop; Gary Anderson, a 23-year-old University of Southern California student, designed it for a 1970 Container Corporation of America contest tied to Earth Day and won a $2,500 scholarship.

By count, the Great Pacific Garbage Patch consists mostly of what?

Less an island than a soup: microplastics dominate by count, about 94% of an estimated 1.8 trillion pieces, though 92% of the mass is larger objects like ghost nets; a 2018 study put its area at 1.6 million square kilometres.

Which Olympic Games made its medals from metal recovered from donated mobile phones and other old electronics?

Tokyo 2020 ran a two-year collection drive backed by about 90% of Japan's local authorities, and reclaimed enough gold, silver and bronze for all of the Games' roughly 5,000 medals.

About what share of Earth's surface is dry land?

About 29% is land; oceans cover the other 71%, yet as of 2026 barely more than a quarter of the seafloor had been mapped in detail.

What is ocean acidification?

Seawater absorbing CO2 and its pH falling by about 0.1 sounds slight, but the scale is logarithmic, and the shift already makes it harder for corals and shellfish to build shells.

Which environmental hazard did a major 2024 health report link to 8.1 million deaths worldwide in 2021?

Air pollution had moved ahead of tobacco and poor diet to become the second leading risk factor for death, behind only high blood pressure.

What is 'e-waste'?

E-waste is discarded electrical or electronic devices, from phones to fridges; a record 62 million tonnes was thrown out in 2022, and under a quarter was properly collected and recycled.

Coral bleaching is primarily caused by what environmental stressor?

Rising ocean temperatures are the main trigger: heat-stressed corals expel the symbiotic algae that feed and colour them, turning white; they can recover if the water cools soon enough.

What does the acronym 'PPM' stand for when measuring gases in the atmosphere?

Parts per million means one molecule in every million; the notation is not part of the SI system and is technically ambiguous, yet it remains the standard way to quote atmospheric gas levels.

Which renewable source generated the most electricity worldwide in 2023?

Hydropower supplied about 14% of the world's electricity in 2023, still more than wind and solar put together; the two were growing so fast that they jointly overtook it in 2024.

Which of the nine Amazon nations holds about 60% of the rainforest?

Brazil holds about 60% of the Amazon; the 'lungs of the Earth' tag is a myth, since the forest's own respiration consumes nearly all the oxygen it produces.

What is the main cause of deforestation worldwide?

Farming and cattle ranching drive most forest loss: FAO's 2022 remote-sensing survey found agricultural expansion, mainly cropland and cattle pasture, behind almost 90% of global deforestation between 2000 and 2018.

Which animal is the symbol of the World Wildlife Fund (WWF)?

The giant panda logo, drawn by Sir Peter Scott in 1961, was inspired by Chi Chi, then the only panda living in the Western world, at London Zoo; the species was downgraded from endangered to vulnerable in 2016.

Which reptile left the US endangered species list, fully recovered, in 1987?

The American alligator was listed in 1967 after hunters seeking its hide had left its survival in doubt; once hunting was outlawed it rebounded within twenty years.

Solar panels convert sunlight into electricity using what type of cell?

Photovoltaic cells turn light directly into current; the first silicon ones were too costly to sell widely, and their first real job was in space, powering satellites from the late 1950s.

Which group of animals accounts for more than half of all the animal species that science has described?

Insects account for over a million named species, yet a 2011 census estimated that about 86% of all the species on Earth have still to be described at all.

What is the term for a region with exceptionally rich but severely threatened plant and animal life?

Biodiversity hotspots, a term coined by Norman Myers in 1988, number 36; their remaining habitat covers about 2.5% of the land surface yet holds more than half of all plant species as endemics.

Which country installed the most new solar power capacity in 2023?

China commissioned as much solar in 2023 as the whole world had the year before, as a glut from its own factories cut panel prices by almost half; its total passed 600 gigawatts.

Which word did environmentalist Jay Westerveld coin in 1986 after a hotel urged guests to reuse towels 'to save the environment'?

Greenwashing was his label for green claims that hide ordinary motives: he argued the hotels did little to cut waste and mainly wanted to save on laundry bills.

What is composting?

Decomposing organic waste into a soil amendment is the work of microbes, and a well-built heap can pass 55°C, hot enough to kill weed seeds and many germs.

Which body publishes the 'Red List' of threatened species?

IUCN, the International Union for Conservation of Nature, began the list in 1964; the naturalist Sir Peter Scott, a founder of WWF, helped create its Red Data Books.

Which salt-tolerant coastal trees blunt storm surges with their tangled roots and bury carbon in waterlogged mud?

Mangroves trap sediment among their roots, building up the muddy shore and steadying it against waves and tides, while the airless mud keeps buried carbon from rotting away.

What does the term 'sustainability' generally mean?

Meeting today's needs without robbing the future paraphrases the UN's 1987 Brundtland Report, which made 'sustainable development' a household phrase.

Which bird, nearly wiped out by DDT, left the US endangered species list in 2007?

The bald eagle absorbed DDT from the fish it ate, and its eggshells grew too thin to survive nesting; numbers climbed back once the chemical was banned in 1972.

Which 1997 treaty, named for the Japanese city where it was adopted, set binding greenhouse-gas targets for developed countries?

The Kyoto Protocol bound only developed countries, and the United States signed but never ratified it: the Senate had already voted 95 to 0 against any deal that exempted developing nations.

Which environmental organization was founded in 1971 after activists protested nuclear testing in Alaska?

Greenpeace began when its founders sailed a chartered fishing boat, the Phyllis Cormack, from Vancouver toward Amchitka in September 1971 to protest the Cannikin nuclear test; the test went ahead that November.

What is a 'carbon sink'?

Forests, soils and the ocean between them soak up roughly half of what humans emit each year; each is a reservoir that absorbs more CO2 than it releases.

Where is most of Earth's fresh water, more than two-thirds of it, to be found?

Glaciers and ice caps lock up over 68% of the planet's fresh water and groundwater holds nearly all the rest; the lakes and rivers people rely on amount to well under 1%.

Which term means planting trees on land that was forest until it was cleared?

Reforestation restores forest that was cleared; its sibling, afforestation, plants where none stood, which can backfire on natural grasslands that were never meant to be forest.

Suspicious critics noted that the first Earth Day fell on the 100th birthday of which communist figure?

Vladimir Lenin was born exactly a century before the first Earth Day, a coincidence the founder had not noticed. Time magazine reported that some Americans suspected 'a Communist trick'.

Which Dr. Seuss character 'speaks for the trees' and confronts a business magnate called the Once-ler?

The Lorax was Dr. Seuss's personal favorite among his own books. In 1988 some residents of one school district complained that the story was unfair to the logging industry.

Which 2008 Pixar film follows a lonely trash-compacting robot left to tidy an abandoned, garbage-strewn Earth?

WALL-E stands for Waste Allocation Load Lifter: Earth-class, and he is the last robot of his kind still working. The film won the Academy Award for Best Animated Feature.

Which former American vice president turned his climate slide show into the documentary An Inconvenient Truth?

Al Gore had given the talk more than 1,000 times, by his own estimate, before it reached cinemas. The film won two Academy Awards, for best documentary and best original song.

Which Australian wonder, visible from space, is the world's biggest structure made by living organisms?

Great Barrier Reef corals are tiny animals called polyps, and billions of them built the structure. It lies in the Coral Sea off the coast of Queensland.

Which food emits about 60 kilograms of greenhouse gases for every kilogram produced, the most of any common food?

Beef from beef herds tops a ranking of 29 foods, while a kilogram of peas emits about one kilogram. What people eat matters far more for emissions than whether it is local.

Leatherback sea turtles often swallow drifting plastic bags because the bags look like which favorite prey?

Jellyfish make up almost the whole diet of adult leatherbacks, so a floating bag is easily mistaken for a meal. An estimated one-third of adult Pacific leatherbacks have swallowed plastic.

Which nuclear plant exploded in 1986, leaving an evacuated zone where forests and wildlife have since thrived?

Chernobyl's exclusion zone in northern Ukraine now holds some of the country's thickest forests. With almost no human activity since the evacuation, it has become a thriving sanctuary.

Which toxic metal vanished from car fuel worldwide in 2021, when Algeria sold the last gasoline containing it?

Lead was first mixed into gasoline in the 1920s to stop engines knocking. The United Nations declared an official end to its use in cars on 30 August 2021.

The date of the first Earth Day was picked to avoid exams and spring break for which group?

College students were the crowd the founder most wanted, so he chose a midweek date clear of exams and vacations. It also avoided Easter and Passover.

Which U.S. Forest Service mascot, introduced in 1944, warns campers that only they can prevent wildfires?

Smokey Bear fronts the longest-running public service ad campaign in American history. A real black bear cub rescued from a 1950 wildfire in New Mexico later became his living symbol.

Which British broadcaster has narrated the BBC nature epics Planet Earth, The Blue Planet and Frozen Planet?

David Attenborough began presenting with Zoo Quest in 1954, and his career has spanned seven decades. Planet Earth in 2006 was the first BBC wildlife series shot in high definition.

Which British primatologist began watching wild chimpanzees at Gombe in Tanzania in 1960 and saw them use tools?

Jane Goodall watched a chimpanzee fish for termites with grass stalks, overturning the belief that only humans use tools. Her mentor Louis Leakey raised the money for the trip.

Which park, signed into law by Ulysses S. Grant, is widely seen as the world's first national park?

Yellowstone was set apart in 1872 'for the benefit and enjoyment of the people'. The painter George Catlin had floated the idea of a national park back in the 1830s.

Colony collapse disorder makes most adult workers of which insect vanish, leaving a queen and food behind?

Honey bee hives struck by the disorder still hold a queen, plenty of food and a few nurse bees. The name was coined after a sudden wave of losses across North America.

Which butterfly, whose caterpillars eat only milkweed, flies from Canada to winter in Mexican fir forests?

Monarch butterflies from eastern North America head south each autumn and cluster on oyamel firs through the winter. Milkweed gives their caterpillars protective toxins.

Which type of light bulb makes light up to 90% more efficiently than old-fashioned incandescent bulbs?

LED lighting wins because incandescent bulbs release about 90% of their energy as heat. When designed well, it is also more versatile and lasts longer.

Which metal can be recycled again and again, using up to 95% less energy than making it from ore?

Aluminum scrap only needs re-melting, which is far cheaper than refining new metal from bauxite. That has made it one of the most recycled materials in use.

Above which continent did British scientists report a huge seasonal hole in the ozone layer in 1985?

Antarctica's ozone loss shocked researchers because it was far larger than anyone had predicted. Up to 70 percent of the ozone overhead vanished each southern spring.

Which Ecuadorian archipelago of giant tortoises and finches inspired Charles Darwin's theory of natural selection?

The Galápagos take their name from an old Spanish word for the giant tortoises Darwin saw there in the 1830s. UNESCO made the islands a World Heritage Site in 1978.

The first Earth Day was originally planned as a nationwide version of which Vietnam-era protest format?

Teach-in was the working label until an advertising writer suggested a snappier name. Organizers found the term stale, and such events implied a debate when nobody was arguing for pollution.

The senator who founded Earth Day had earlier served two terms as governor of which Midwestern state?

Wisconsin's conservationist senator had long looked for a way to make the environment a bigger political issue. He later received the Presidential Medal of Freedom for the work.

Julian Koenig, who coined the name Earth Day, also wrote the famous 'Think Small' ads for which carmaker?

Volkswagen's 'Think Small' was later named the greatest advertising campaign of the 20th century by Advertising Age. Koenig liked 'Earth Day' partly because it rhymed with 'birthday'.

The Earth Flag flown at Earth Day events shows The Blue Marble, a photograph taken by the crew of which mission?

Apollo 17 astronauts took the picture in December 1972 on their way to the Moon. Earlier versions of the flag carried a photo from Apollo 10 instead.

On one Earth Day, world leaders gathered in which city to sign the Paris climate accord?

New York hosted the ceremony at United Nations headquarters, on a date picked deliberately. The deal had been struck in France four months earlier.

John McConnell's version of Earth Day, marked each year at the United Nations, falls on which astronomical event?

March equinox ceremonies at the UN include ringing the Japanese Peace Bell at the exact moment spring begins in the north. San Francisco's mayor issued the first proclamation for the day.

Which Joni Mitchell song, written on her first trip to Hawaii, laments that they 'paved paradise'?

Big Yellow Taxi came to Mitchell after she threw back her hotel curtains and saw green mountains, then a parking lot as far as the eye could see. The sight, she said, broke her heart.

Which astronomer urged NASA to turn Voyager 1 around for a last photo of Earth, the 'Pale Blue Dot'?

Carl Sagan pressed for the shot for years, and the probe finally took it in 1990 from more than 6 billion kilometers away. Earth fills less than a single pixel of the frame.

Which Scottish-born naturalist co-founded the Sierra Club and is called the 'Father of the National Parks'?

John Muir helped start the club in 1892 after a Berkeley professor proposed an 'alpine club' for mountain lovers. Admirers also knew him as 'John of the Mountains'.

Which American president put about 230 million acres under public protection and created five national parks?

Theodore Roosevelt also founded the Forest Service and used the 1906 Antiquities Act to proclaim 18 national monuments. Earlier he had started the Boone and Crockett Club to conserve big game.

Which Kenyan founder of the Green Belt Movement became the first African woman to win the Nobel Peace Prize?

Wangari Maathai won in 2004 for her contribution to sustainable development, democracy and peace. She was also the first environmentalist to take the prize.

Which holiday began in Nebraska when settlers planted an estimated one million trees in a single day?

Arbor Day was proposed by J. Sterling Morton of Nebraska City at a meeting of the state board of agriculture. Countries around the world now hold tree-planting days of their own.

Which South American city hosted the 1992 Earth Summit, where the first United Nations climate treaty was launched?

Rio de Janeiro's summit set up the UN Framework Convention on Climate Change, meant to prevent 'dangerous human interference with the climate system'. Later climate deals were negotiated under it.

Which oil tanker struck Bligh Reef in Alaska's Prince William Sound in 1989, fouling 1,300 miles of coastline?

Exxon Valdez spilled more than 10 million gallons of crude, killing at least 100,000 seabirds and 2,800 sea otters. The remote location made the cleanup especially hard.

Which insecticide was banned on American farms in 1972 after it was found to thin the eggshells of birds of prey?

DDT built up in ospreys, peregrine falcons and brown pelicans until their eggs cracked before hatching. The ban is credited as a major factor in the comeback of America's national bird.

Which problem arises when sulfur dioxide from smokestacks mixes with moisture in the air and falls on forests?

Acid rain forms as the gas turns into sulfuric acid, which harms fish, soils and even stone buildings. Volcanic eruptions produce some of the same gas naturally.

Which British city's Great Smog of December 1952 killed thousands of people in just five days?

London's smog lasted from 5 to 9 December, and modern estimates put the death toll at 10,000 to 12,000. New laws in the following years cut the smoke over British cities.

Which tiny drifting ocean organisms produce most of the sea's share of Earth's oxygen, roughly half the total?

Plankton that can photosynthesize, including drifting algae and some bacteria, make the majority of the ocean's oxygen. Marine life breathes in about as much as the sea produces.

Which North American bird, once numbering in the billions, died out when Martha died at the Cincinnati Zoo in 1914?

Passenger pigeon numbers peaked at three to five billion, and one 1866 flock took 14 hours to pass overhead. Martha, the last of them, was frozen in a block of ice and sent to the Smithsonian.

Which South Asian country became the first to ban thin plastic bags, in 2002, after they were blamed for floods?

Bangladesh acted after floods linked to littered bags had submerged two-thirds of the country. Ireland's bag levy the same year cut usage by 90% within weeks.

Which activist, later head of the Solar Energy Research Institute, was national coordinator of the first Earth Day?

Denis Hayes later took Earth Day international, organizing events in 141 countries. He picked the title coordinator because 'director' sounded too hierarchical for the times.

Which South American country led the 2009 United Nations resolution that created International Mother Earth Day?

Bolivia introduced the resolution, which more than 50 member states endorsed. The General Assembly then adopted it by consensus.

Which labor union, led by Walter Reuther, was the biggest financial backer of the first Earth Day?

United Auto Workers money paid for the phones, printing and mailings, and Reuther made the first donation of $2,000. The chief organizer said the day would likely have flopped without it.

Which comic-strip character declared 'We have met the enemy and he is us' on a poster for the first Earth Day?

Pogo, a possum from the Okefenokee Swamp, spoke the line in an anti-pollution poster by cartoonist Walt Kelly. It twists a naval hero's boast, 'We have met the enemy and they are ours.'

Which organization launched its famous 'Crying Indian' television ad on the second annual Earth Day?

Keep America Beautiful paired the tearful close-up with the slogan 'People start pollution; people can stop it'. The actor, Iron Eyes Cody, was in fact of Italian descent.

Which Swedish chemist, trying to explain the ice ages in 1896, first calculated how changes in the air could warm Earth?

Svante Arrhenius worked out his estimates from basic principles of physical chemistry. In 1903 he became the first Swedish Nobel laureate, taking the chemistry prize.

Which Niagara Falls neighborhood, built beside a buried chemical dump, prompted America's Superfund cleanup law?

Love Canal was an unfinished waterway that a chemical company filled with nearly 20,000 tonnes of waste. The firm later sold the land to the local school district for $1.

Which Cleveland river caught fire in 1969, an oil-slick blaze that helped spur America's environmental movement?

Cuyahoga fires were nothing new, since the river had burned at least a dozen times since 1868. The 1969 blaze did only about $50,000 of damage, but later news coverage made it a national cause.

The Keeling Curve, a graph of the changing atmosphere kept since 1958, is measured atop which Hawaiian volcano?

Mauna Loa readings have risen steadily ever since Charles David Keeling began them. His son Ralph took charge of the project after Keeling died in 2005.

The Ramsar Convention, signed in 1971 at an Iranian resort on the Caspian Sea, protects which type of habitat?

Wetlands of international importance are listed under the treaty, which was written with waterfowl especially in mind. World Wetlands Day marks its adoption every 2 February.