“Fifty Things We’ve Learned About The Earth Since The First Earth Day”, Smithsonian Magazine

Published April 22, 2020

April 22, 2020

On April 22, 1970, Americans pledged environmental action for the planet. Here’s what scientists and we, the global community, have done since

When Gaylord Nelson stepped up to the podium in April 1970, his voice rang with powerful purpose. The Wisconsin senator set forth a challenge for America—a call to arms that he declared a “big concept”: a day for environmental action that would go beyond just picking up litter.

“Winning the environmental war is a whole lot tougher than winning any other war in history,” he said. “Our goal is not just an environment of clean air and water and scenic beauty. The objective is an environment of decency, quality and mutual respect for all other human beings and all other living creatures.”

In the half-century since concerned people all across the United States took steps to repair a world rife with pollution, litter, ecological devastation, political apathy and wildlife on the brink, great strides have been made and major setbacks have been recorded. An estimated 20 million Americans volunteered their time and energy to live up to Nelson’s goal. Inspired by man-made disasters like the burning of Ohio’s Cuyahoga River and an oil spill in Santa Barbara, California, environmentalists of the day pushed the nation and the world to recognize the damage they were inflicting on the planet and to change course. Social justice lawyers and urban city planners took up the hard effort of bringing this vision to the impoverished, the hungry and the discriminated.

Today, when not battling a deadly pandemic that has shut down the world economy, Earth’s citizens continue that struggle, challenged by the consequences of global climate change in the form of increasingly catastrophic natural disasters, a depletion of necessary resources, and humanitarian crises on an unprecedented scale. At the same time, scientists, innovators and younger generations are fighting back against these forces and offering reasons for hope and optimism.

In honor of the 50th anniversary of Earth Day, and the 50th anniversary of Smithsonian magazine, the staff of Smithsonian magazine challenged scientists, historians, researchers, astrophysicists, curators and research scholars across the Smithsonian Institution to identify something about the planet that has been revealed over the past 50 years. Read on and be inspired—and sometimes saddened—by their responses—the things achieved and the struggles still ahead.

The Age of Humans

That Humans Created a New Epoch: the Anthropocene

Our improved understanding of the geological history of Earth helps us understand how the atmosphere, oceans, soils and ecosystems all interact. It also gives us a new perspective on ourselves: We are pushing the Earth to depart radically from the state it has been in for several million years or longer. Our models show that our use of energy and resources will have side effects that persist for hundreds of thousands of years into the future. These realizations have given rise to a new term—the Anthropocene, or Age of Humans. We lack the ability to destroy the Earth, thank goodness, but if we want to leave it in a condition that is pleasant for humans, we have to learn to work within the limits and constraints that its systems impose. Our scientific understanding tells us what we need to do, but our social systems have lagged behind in helping us implement the needed changes in our own behavior. This little essay is being written from self-quarantine because of the worst global pandemic in a century. The human tragedies of COVID-19 should remind us of an important principle. It is difficult or impossible to stop exponential processes like the spread of a virus—or, the growth of human resource use. Global change is generally slower and more multifarious than this pandemic, but it has a similar unstoppable momentum. The sooner we flatten the curve of our resource consumption, the less harm we will cause to our children and grandchildren. If we bring our consumption of resources and energy into line with the ability of the planet to replenish them, we will truly have inaugurated a new epoch in Earth history. —Scott L. Wing, paleobiologist, National Museum of Natural History

That the Polar Ice Caps Are Melting

The Arctic that existed when I was born in 1980 was more similar to the one that 19th-century explorers saw than it will be to the one my children will know. Each year since 1980, winter sea ice has steadily dropped, losing more than half its geographic extent and three-quarters of its volume. By the mid-2030s, Arctic summers may be mostly free of sea ice. The Arctic is undergoing a fundamental unraveling that has not happened since it first froze over more than three million years ago, a time before the first bowhead whales. These filter-feeding whales are known as the one true polar whale for good reason—they alone have the size and strength to deal with the vicissitudes of ice, including the wherewithal to break it up should it suddenly begin to close up around a breathing hole. Mysteriously, bowheads can live up to 200 years. A bowhead calf born today will live in an Arctic that, by the next century, will be a different world than that experienced by all of its ancestors; as the Arctic unravels within the scale of our own lifetime, some of these bowheads may still outlive us, reaching a bicentenarian age in an Arctic Ocean with far less ice and many more humans. —Nick Pyenson, curator of fossil marine mammals, National Museum of Natural History. This passage is adapted from his book, Spying on Whales.

That Feedlot Cattle Increase Methane Emissions

In 1978, the U.S. raised almost twice as many bovine animals as it had in 1940. The emergence of industrial feedlots made this explosion possible. The country’s nearly 120 million ruminant animals, increasingly being fed a diet of grains laced with hormones and antibiotics, were concentrated into industrialized feeding operations. The tremendous population growth that feedlots made possible, however, came with an unexpected consequence: a dramatic rise in methane emissions. In 1980, atmospheric scientist Veerabhadran Ramanathan discovered that trace gases such as methane were extremely potent greenhouse gases, with a warming potential on an order of magnitude greater than CO2. And in 1986, climate scientist and Nobel laureate Paul Crutzen published an article that put the burden of increasing methane emissions on the cattle industry in unequivocal terms. Crutzen explained that 15 to 25 percent of total methane emissions were of animal origin, and “of this, cattle contribute about 74 percent.” Crutzen and others, thus confirmed that growing bovine numbers, were one of the largest factors behind the rise of methane emissions. —Abeer Saha, curator of engineering, work and industry division, National Museum of American History

That Parasites Can Hitchhike Around the World in Ships

In the last decade, we’ve discovered that parasites move around the world’s oceans faster and in far larger numbers than we thought. Commercial shipping is the main way goods move from place to place, transporting millions of metric tons of cargo a year. In two studies published in 2016 and 2017, my colleagues and I used DNA-based methods to search for parasites in ballast water (the water that ships take on board and hold in special tanks for balance). We’ve discovered that ballast tanks are full of parasites known to infect many different marine organisms. In our 2017 study, we found some parasite species in all of our samples, from ships docking in ports on the East, West and Gulf Coasts of the U.S. This signals a huge potential for parasite invasions. Knowing these ships are unwittingly ferrying parasites means we can act to limit the future spread of parasites and the diseases they cause. —Katrina Lohan, marine disease ecology laboratory, Smithsonian Environmental Research Center

That the Arctic Is Now at the Center of Global Interests

The year 1970 was a good one for the Arctic. Northern regions buried in snow with lots of winter ice. Polar bear populations were high, and the seal hunt was producing a good income for Inuit hunters before French actress Brigitte Bardot’s protest killed peltry fashion. Meanwhile, scientists studying the Greenland ice cores were predicting the Holocene was over and the world was headed into a new ice age. What a difference 50 years can make. Today the Arctic is warming at a rate twice that of the rest of the world; summer pack ice may be gone by 2040 with trans-Arctic commercial shipping and industrial development soon to begin, and Arctic peoples are now represented at the United Nations. In 50 years, the Arctic has been transformed from a remote periphery to center stage in world affairs. —Bill Fitzhugh, curator and anthropologist, Arctic Studies Center, National Museum of Natural History

That Plastics Are Not the Savior We Were Looking For

The first Earth Day may have been observed 100 years after the invention of the first synthetic plastic, but it took place just three years after Dustin Hoffman’s character in The Graduate was advised, “There’s a great future in plastics.” Though criticized in the 1970s as a technology of cheap conformity, plastics were nonetheless sought out as unbreakable, thus safer for packaging hazardous materials; lightweight, thus environmentally beneficial for transportation; easily disposable, thus reducing disease spread in hospitals; and suitable for hundreds of other applications.

But synthetic plastics were designed to persist, and now they are present on every square foot of the planet. If uncaptured by reuse or recycling streams, a significant amount degrades into small bits called microplastics, which are smaller than five millimeters and can be as small as a virus. These small pieces of plastic circulate in waterways, air and soils around the world. Microplastics infiltrate the food chain as animals inadvertently consume plastics. Tiny deep ocean filter feeders have been found with microplastics in their bodies, as have fish, birds, humans and other animals. By one estimate, the average American will consume or inhale between 74,000 and 121,000 particles of microplastics this year. So far, we do not know the full implications of our microplastic-filled world. Chemical leaching from plastics can affect reproductive systems in organisms. Small bits of plastics can accumulate enough to cause blockages. The challenge ahead is to invent new materials that have properties we need—lightweight, flexible, able to block disease transmission, and so on—but that do not persist. —Arthur Daemmrich, director, Lemelson Center for the Study of Invention and Innovation; —Sherri Sheu, environmental historian, research associate, National Museum of American History

Flora and Fauna

That Giant Pandas Can Be Saved

Ever since the groundbreaking work of conservation biologist George Schaller and his colleagues in the 1980s, we have known the key ingredients required for bringing giant pandas back from the brink. They need mature forest with a bamboo understory, adequate birthing dens for raising their precocial young, and protection from poaching. Leaders within the Chinese conservation community, such as Pan Wenchi, used this knowledge to advocate for a ban on forest cutting and the creation of a national reserve system focused on giant pandas. The unprecedented outflow of funds from the Chinese government and the international NGOs has resulted in the creation, staffing and outfitting of more than 65 nature reserves. Taking place every ten years, the National Giant Panda Survey involves hundreds of reserve staff and documents the return of this species to much of its suitable habitat. Meanwhile, zoos throughout the world cracked the problems of captive breeding, and now sustain a population of more than 500 individuals as a hedge against collapse of the natural populations. In 2016, this massive effort paid off. The IUCN Redlist downgraded giant pandas from endangered to vulnerable conservation status, proving it is possible with a few critical advocates and an outpouring of support to put science into action. —William McShea, wildlife ecologist, Smithsonian Conservation Biology Institute

That Critical Mangrove Habitat is Thriving Again

A bridge between land and sea, mangrove forests are among the most productive and biologically complex ecosystems on Earth. Found throughout the tropics and subtropics, mangroves provide critical habitat for numerous marine and terrestrial species and support coastal communities by slowing erosion, cleaning water and much more. In 2007, after decades of rampant losses, scientists sounded the alarm: Without action, the world would lose its mangroves within the next century. In just ten years, concerted, coordinated global efforts have started to pay off. Improved monitoring and increased protections for mangroves have resulted in slower rates of loss. Governments and communities around the world have begun to embrace and celebrate mangroves. A member of the Global Mangrove Alliance and partner in conservation and restoration throughout the American tropics, the Smithsonian is contributing to ambitious goals aimed at protecting and conserving these important habitats.—Steven Canty, biologist, Smithsonian Marine Station; Molly Dodge, program manager, Smithsonian Conservation Commons; Michelle Donahue, science communicator, Smithsonian Marine Station; Ilka (Candy) Feller, mangrove ecologist, Smithsonian Environmental Research Center; Sarah Wheedleton, communications specialist, Smithsonian Conservation Commons

That Animals Like the Golden Lion Tamarin Can Be Brought Back From Near Extinction

In the 1970s, only 200 golden lion tamarins (GLTs) existed in their native Atlantic forest, located just outside of Rio de Janeiro, Brazil. Centuries of deforestation had reduced their habitat by a whopping 98 percent, and that along with their capture for the pet trade had decimated their numbers. In an unprecedented collaboration, Brazilian and international scientists led by the Smithsonian’s National Zoo accepted the challenge to rescue the species from certain extinction. Zoos genetically managed a captive breeding population and soon 500 GLTs were being cared for across 150 institutions. From 1984 to 2000, descendants of the reintroduced zoo-born GLTs flourished in the wild and Brazil’s dedicated GLT conservation group,Associação Mico-Leão Dourado, led an environmental education program that sought an end to illegal deforestation and the capture of GLTs. By 2014, 3,700 GLTs occupied all remaining habitat. In 2018, yellow fever reduced that number to 2,500. A painful setback, but the conservation work continues. —Kenton Kerns, animal care sciences, National Zoo

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