10 Key Moments That Shaped Environmental History

1985: Antarctic ozone hole discovered.

Researchers discover a 7.3 million–square-mile hole in the ozone layer over Antarctica. Within two years the United States and more than 100 other countries pledge to phase out the use of ozone-depleting compounds known as chlorofluorocarbons, or CFCs.

1997: Hybrid cars gain ground.

Toyota introduces the Prius in Japan, making a hybrid gas-electric vehicle widely available to consumers for the first time. Hybrid models, now available from many automakers, emit about half as much carbon dioxide as gasoline-powered vehicles.

2006: An Inconvenient Truth sheds light on climate change.

Opening to packed theaters around the country, the Oscar-winning documentary highlights former Vice President Al Gore's efforts to educate people about global warming and spurs widespread awareness of human contributions to climate change.

2007: Bald eagle comes back from the brink.

Challenger, a bald eagle, is released during an event marking the removal of the bald eagle from the endangered species list.

Win McNamee/Getty Images

Following decades of conservation, the American bald eagle is removed from the endangered species list, after more than 10,000 nesting pairs (up from approximately 400 in 1963) are observed in the lower 48 states.

2015: The Great Pacific Garbage Patch is mapped.

In August 2015 around 30 vessels cross the Great Pacific Garbage Patch for the largest ever ocean research expedition. Located between California and Hawaii, the patch is three times the size of France and contains 80 million kilograms of floating plastic debris.

2016: The Paris Agreement goes into effect.

As part of the Paris Agreement, a landmark international accord to combat climate change, signatory countries agree to limit global temperature rise in the 21st century to 2 degrees Celsius above preindustrial levels.

2019: Greta Thunberg ushers in a new generation of activism.

Sixteen-year old Swedish environmental activist Greta Thunberg is named Time's 2019 “Person of the Year” for her climate change activism, including urging fellow students to rally for the environment and speaking forcefully at the United Nations Climate Action Summit.

"The world is waking up,” she said in an emotional speech addressing world leaders. “And change is coming, whether you like it or not."

— Additional reporting by Stephanie Mansfield