Why We Celebrate Earth Day

April 22, 2020

Earth Day is important to us here at The Earth Institute because it’s the one day of the year when everyone celebrates something that matters a lot to us: our beautiful planet.

Earth Institute scientists have been investigating the planet’s mysteries for more than 70 years. They have plumbed the depths of the oceans, scaled the tallest mountains, and traversed every continent in order to broaden and deepen our understanding of the world. Along the way, they’ve made incredible discoveries that shook the world of science.

Researchers at our Lamont-Doherty Earth Observatory were the first to propose that ice ages are driven by natural cycles of freezing and thawing in the Arctic Ocean. Lamont’s Marie Tharp was the first to map the ocean floor on a global scale. Mark Cane and Stephen Zebiak, researchers at our International Research Institute for Climate and Society, helped to create the first model to explain and predict the powerful El Niño climate cycle, which affects affect crops, disease outbreaks and natural hazards all over the world. And the term “global warming” came from our own Wallace Broecker, who was among the first scientists to warn of the dangers of rising global temperatures.

The photos below provide more examples of how Earth Institute researchers have been at the forefront of Earth and environmental science.

1956 - A Theory of Ice Ages. Maurice “Doc” Ewing, one of the world’s most influential oceanographers and Lamont’s first director, teamed with geologist William Donn to propose that ice ages are driven by self-perpetuating natural cycles of freezing and thawing of the Arctic Ocean. Although scientists’ views shifted radically as more evidence came in, this initiated Lamont’s tradition of studying large-scale climate swings. In this photo: Maurice “Doc” Ewing in 1948. Credit: Lamont-Doherty Earth Observatory


Maurice “Doc” Ewing at the research vessel Vema’s wheel with crew and scientists. Ewing pioneered the use of shock waves to map the seafloor (later adapted for underwater monitoring of vessels and marine life), and helped to develop seismographs that were used to establish the first global earthquake monitoring network consisting of calibrated uniform instrumentation. Credit: Lamont-Doherty Earth Observatory


Fifty years ago, when astronauts first landed on the moon, they carried not only humanity’s highest hopes, but an important seismology experiment from Columbia. Photo: NASA


The First Earth Day, April 22, 1970 at Columbia. Columbia held Earth Day teach-ins, marches, and rallies, and the University Senate was trying to get Columbia trustees to use the University’s 57,000 shares of General Motors stock to pressure the company to reform its safety and environmental policies. Credit: Columbia Daily Spectator


1973 - Global Warming. One of the first scientists to predict an imminent rise in the Earth’s temperature due to human output of carbon dioxide, Wallace Broecker was credited with introducing the phrase “global warming” into the scientific lexicon in a 1973 paper. In this photo: Wallace Broecker receiving the National Medal of Science from President Bill Clinton in 1996. Credit: Lamont-Doherty Earth Observatory


1976 - Variations in the Earth’s Orbit: Pacemaker of the Ice Ages. A paper by James Hays, John Imbrie, and Nicholas Shackleton proves, to most scientists' satisfaction, that Earth's ice ages coincide with changes in how the planet orbits the sun. The idea had been long debated. Lamont’s James Hays worked with two other giants of modern science: Brown University’s John Imbrie and Cambridge’s Nicholas Shackleton. Lamont’s James Hays worked with two other giants of modern science: Brown University’s John Imbrie and Cambridge’s Nicholas Shackleton.


1977 - Ocean Seafloor Map. Pioneering mapmaker Marie Tharp was the first to chart the topology of the ocean floor on a global scale. In this photo: Marie Tharp working in the early 1960s on the physiographic diagram of the Indian ocean in Lamont’s oceanography building at Columbia University. Credit: Lamont-Doherty Earth Observatory


1980s - Great Ocean Conveyor Belt. Wallace Broecker showed how carbon isotopes could be used to map ocean currents that we now know form a series of global-scale loops. This led to an overarching model of the “Great Ocean Conveyor Belt” and the idea that changes in the conveyor may bring sudden, powerful shifts in the global climate. Credit: Wallace Broecker


1986 - Experimental Forecasts of El Niño. El Niño is a powerful natural climate cycle that shifts precipitation and temperature patterns, affecting crops, disease outbreaks and natural hazards globally. Its physics and variable timing were long cloaked in mystery. Mark Cane and Stephen Zebiak were the first to construct a model that explained how El Niño worked, and successfully predicted an El Niño in 1986. Image: NASA


The Tree Ring Lab at Lamont-Doherty Earth Observatory collects cores from trees around the world in order to reconstruct Earth’s climate history. In this photo: Tree ring scientists Ed Cook (left) and Paul Krusic trekked for nearly two weeks to reach this 1,000-year-old hemlock in the Himalayas of Nepal. Credit: Brendan Buckley


1988 - James Hansen’s Climate Warning. Hansen testifies before a Senate transportation subcommittee on 8 May 1989, a year after his history-making testimony that helped to increase public awareness of climate change. Credit: Dennis Cook/AP


R/V Marcus G. Langseth, Exploring New Depths. The research vessel Marcus G. Langseth, operated by Lamont-Doherty Earth Observatory, traverses the world’s oceans conducting marine seismic studies that contribute to new understanding of Earth systems. Credit: Lamont-Doherty Earth Observatory


Lamont Core Repository. The Core Repository is the most extensive collection of deep sea sediments on Earth. The cores contain layers of sediments deposited on the bottom of the ocean over millions of years. They are loaned to scientists worldwide to learn more about Earth's climate history. Credit: Francesco Fiondella


Maureen Raymo with an ocean sediment core. Raymo is a paleoclimatologist, marine geologist, and director of the Core Repository. Her work has shaped our understanding of how the ice ages fluctuate and how sea levels change. Credit: Lamont-Doherty Earth Observatory


2014 - National Medal of Science. President Barack Obama bestows the National Medal of Science, the nation’s top scientific honor, to MESSENGER principal investigator and director of Columbia University’s Lamont-Doherty Earth Observatory, Sean Solomon. The award was presented on Thursday, Nov. 20, 2014 during a ceremony in the East Room of the White House in Washington. MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. Photo: NASA/Bill Ingalls


At the CarbFix test site in Iceland, carbon dioxide from a geothermal power plant are pumped underground and converted into minerals by reacting with basalt stone. In this photo: Gases dissolved in water are piped to this injection shed, a half-mile from the power plant. Credit: Kevin Krajick


Lamont-Doherty Earth Observatory’s Marco Tedesco has helped to reveal that the Greenland ice sheet’s surface is getting darker, which increases its risk of melting and causing sea level rise. Photo: Marco Tedesco


Polar scientist Robin Bell is the first woman to have chaired the National Academy of Sciences Polar Research Board. Her research has revealed lakes, rivers, mountains and volcanoes beneath the Antarctic ice sheet. Photo: Lamont-Doherty Earth Observatory


Bioclimatologist Park Williams extracts a core from a massive red oak. Williams’ work has been instrumental in determining how much climate change has contributed to wildfires and megadrought in the Western U.S. Photo: Kevin Krajick


Climate change, in all its aspects, remains a major focus of the Earth Institute today, and our scientists continue to make groundbreaking discoveries in Earth and environmental science.

But the work we do goes far beyond unearthing new information and detailing the problems that humanity faces; we are also deeply invested in finding ways to fix those problems. Our centers and programs are:

On Earth Day and every day, the Earth Institute works to understand and protect our planet. Join us this Earth Day and be part of the solution.

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