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50 Years of Earth Day: What’s Better Today, and What’s Worse

Here are 10 big environmental victories — and 10 big failures.

April 21, 2020

Earth Day turns 50 today. The original wave of coast-to-coast demonstrations in 1970 not only transformed American priorities, leading to landmark legislation like the Clean Air Act, but helped shape the modern global environmental movement.

In the past half-century, air and water pollution have plummeted in the United States, the bald eagle is no longer endangered, and environmental laws pioneered in America have set a model for nations around the world. But since then, other threats have grown, including climate change, tropical deforestation and a staggering loss of global biodiversity.

Here is a look at what’s gotten better and what’s gotten worse in the five decades since millions of people marched to demand a cleaner, healthier environment.

America’s rivers are no longer filthy (or on fire).

In 1969, oil-soaked debris on the Cuyahoga River near Cleveland briefly caught fire. The blaze was small, and extinguished quickly, but consequential: It became a galvanizing symbol for a clean-water movement at the heart of the first Earth Day.

The nation’s waterways were astonishingly dirty at that time. Cities large and small were flushing raw sewage into rivers without treating it. One study found that 90 percent of drinking water systems in eight metro areas had excess levels of microbes of the sort that were making people ill by the thousands.

The Cuyahoga River on Nov. 1, 1952.Bettmann/Getty Images

“There was a sense that rivers and lakes had just become sewers,” said Adam Rome, a historian at the University at Buffalo.

Time magazine in 1969 captured the filthy state of the nation’s water in an exposé that highlighted the fire on the Cuyahoga, elevating the blaze to legendary status (even though river fires were a fading problem by then, thanks to local efforts).

Congress soon accelerated the cleanup. The Clean Water Act of 1972 restricted the dumping of waste and led to more than $650 billion in spending on treatment plants. Today, places like Boston Harbor, once a stew of toxic chemicals, are home once again to striped bass, seals and even whales.

Plenty of problems linger. The Environmental Protection Agency still classifies a significant fraction of rivers and streams as “impaired,” though over all, the nation’s waterways are significantly cleaner. And today there is a new water concern: The health of the high seas.

The oceans are warming. And getting more acidic.

Back then, all eyes were on rivers. Today, a bigger concern is the world’s oceans.

A major reason is global warming, which was barely on the nation’s radar in 1970. Ocean temperatures have soared in recent decades, because of increases in heat-trapping greenhouse gases from vehicles and power plants. Many of the richest coral reefs, including the Great Barrier Reef off the coast of Australia, now suffer frequent die-offs.

400 zettajoules

Estimated heat accumulation in the world’s oceans

versus the atmosphere, land and ice

300

200

Oceans

100

Atmosphere, land, ice

1990

2000

2010

1960

1970

1980

400 zettajoules

Estimated heat accumulation in the world’s oceans versus the atmosphere, land and ice

300

200

Oceans

100

Atmosphere, land, ice

1990

2010

1970

Amounts shown in zettajoules, or sextillions of joules, relative to 1971 levels, as in the original IPCC graphic. Sources: Cheng et al., Advances in Atmospheric Sciences; IPCC

There is a wealth of evidence, which didn’t exist during the first Earth Day, that climate change is imperiling a vast array of marine life. By the early 2000s, scientists realized that carbon dioxide emissions from industrial activity would make the oceans dangerously more acidic, throwing ecosystems into disarray.

Fish populations are now declining in many parts of the world as waters warm. Combined with unsustainable fishing practices, that could threaten food supplies and livelihoods.

After Earth Day, environmentalists and policymakers concluded that local efforts were insufficient to clean America’s rivers and lakes. Similarly today, experts say that no single country alone can solve the oceans’ problems. Instead, nations need to work together to limit plastic pollution, rein in overfishing and reduce greenhouse gas emissions to reduce the pressure on marine life.

America’s air is cleaner.

You know those photos we see today of polluted air above the cities of India and Eastern Europe?

It used to be like that in the United States: Pollution thick enough to blot out the sun.

In the 1940s, Pittsburgh was so dark it kept the street lamps on during the day. And in New York City in the decade before 1970, deaths from emphysema rose 500 percent. Air pollution was increasingly considered a key factor. “On the autopsy table, it’s unmistakable,” a city medical examiner said at the time. “The person who spent his life in the Adirondacks has nice pink lungs. The city dweller’s are black as coal.”

New York City in 1966.Neal Boenzi/The New York Times

A few months after the first Earth Day, Congress passed the Clean Air Act, one of the most far-reaching environmental laws in American history. It was part of a wave of government action that would include the creation of the Environmental Protection Agency.

Since then, air quality in the United States has improved tremendously, which has been a boon for public health. Power plants and factories have had to adopt scrubbers and other techniques to clean up emissions. And while automakers initially resisted, they eventually agreed to install technologies like catalytic converters to remove exhaust pollutants.

Today, cars are cleaner. Acid rain has become a trivia question. The E.P.A. estimates that hundreds of thousands of lives were saved in 2020 alone because of the Clean Air Act. And although industry groups initially said regulations would impose crippling burdens, the costs of compliance haven’t kept the economy from growing.

Even so, the E.P.A. says that more than 110 million Americans still live in counties with unhealthy pollution today. And since 2016, particulate pollution has begun to tick back up.

Elsewhere in the world? Not so clean.

Now, about the air in China, India and other developing countries.

Things have gotten bad.

Part of the backdrop for the first Earth Day was that, by 1970, many Americans had become financially secure enough, thanks to decades of economic growth, to focus on curbing the pollution caused by industrial progress.

But it has taken longer for other countries to reach that tipping point.

Fine particulate matter pollution around the world

In China, air quality has improved but remains poor.

Northern India regularly sees hazardous spikes in pollution.

More pollution

Fine particulate matter pollution around the world

In China, air quality has improved but remains poor.

Northern India regularly sees hazardous spikes in pollution.

More pollution

Fine particulate matter pollution hotspots

More pollution

China

Northern

India

Data reflects ground-level fine particulate matter (PM2.5) in 2016, with dust and sea salt removed. Source: NASA

In China, which has built several hundred coal plants since the 1990s, air pollution is reducing life expectancy by about three years on average, one study estimated. In New Delhi, the air became so foul in 2019 that officials declared an emergency, closing schools and distributing millions of face masks. In Poland, aging cars and coal plants have smothered cities in smog.

There are signs of change: China has begun restricting vehicles and coal plants around cities like Beijing. India is investing heavily in solar power.

Still, there’s a long way to go. The World Health Organization estimates that air pollution causes about 7 million premature deaths annually worldwide — more than those from AIDS, malaria and tuberculosis combined.

Oil spills are rarer (if still big sometimes).

From the start, oil has been a dirty business.

The immense gusher at Spindletop, Texas, in 1901, the dawn of the modern age of oil, created a mess so sprawling that “the countryside and crops for miles around were covered with a blanket of oil,” Stephen Harrigan wrote in “Big Wonderful Thing: A History of Texas.”

The oil barons were not environmentalists, and the nation was hungry for energy.

But in 1969, a blowout off the coast of Santa Barbara changed all that, befouling 35 miles of California coastline, sparking national outrage and serving as a catalyst for the first Earth Day. The disaster helped drive dozens of state and federal environmental laws, as well as curbs on offshore drilling.

A duck covered in crude oil near Carpinteria State Beach, Calif., in 1969.Bettmann/Getty Images

Despite that, we still see horrific damage including the Exxon Valdez oil spill in Prince William Sound, Alaska, in 1989, and the Deepwater Horizon disaster in the Gulf of Mexico 10 years ago this month. Overall, though, “the annual number and volume of oil spills have shown declines — in some cases, dramatic declines,” according to a 2017 Congressional Research Service report.

But humans remain addicted to oil.

Back then, it was an oil-spill crisis that rallied attention. Today, it’s the climate crisis.

Between 1970 and 2018, the global use of fossil fuels like coal, oil and natural gas more than doubled.

While that energy has helped lift more than a billion people out of poverty, the burning of fossil fuels releases carbon dioxide, a greenhouse gas that is warming the planet — a threat not as widely appreciated during the first Earth Day.

Scientists have known since the 19th century that shifts in carbon dioxide levels could cause planetary warming. Since then, the scientific evidence has only firmed up that human activity, particularly the burning of fossil fuels, is warming the planet. “It is already happening now,” the NASA scientist James Hansen told Congress in 1988.

Earth has now warmed roughly 1 degree Celsius (1.8 degrees Fahrenheit) since the dawn of the industrial age, and will heat up further unless nations limit and ultimately reverse the rise in emissions. That means finding alternatives to fossil fuels such as oil.

Failure to do so looks ugly. The United Nations scientific panel on climate change said in 2018 that, without aggressive action, many millions more people worldwide could soon be exposed to life-threatening heat waves, water shortages and coastal flooding.

Renewable energy is suddenly serious business.

In recent years, renewable energy sources, notably wind turbines and solar panels, have become credible alternatives to fossil fuels, thanks to tumbling costs.

One result: Some now say climate change might not be as intractable a problem as it once seemed. Al Gore, the former vice president who’s been issuing warnings about climate change for years, said in 2015 the sudden viability of renewables had given him new optimism. “I think most people have been surprised, even shocked, by how quickly the cost has come down,” he said.

It’s quite a shift from 50 years ago. Back then, energy options were largely limited to burning fossil fuels or building nuclear power plants or immense hydropower projects. The latter two often sparked controversy: Think Three Mile Island, or the nasty fights over dams that submerged communities.

Wind and solar were considered fringe during the first Earth Day. Only after the oil crises of the 1970s did policymakers start seriously promoting renewable energy, and those efforts took decades to gain traction. In 1979, President Jimmy Carter installed 32 solar panels on the White House roof to heat water. Two years later, Ronald Reagan ordered their removal.

Today, both wind and solar are mainstream.

The cost of solar panels has fallen more than 99 percent since 1975, and in some regions it has become cheaper to build new wind or solar farms than it is to operate existing coal plants. Solar and wind supplied 6 percent of the world’s electricity in 2017 and are growing at double-digit annual rates.

Clean energy isn’t yet growing fast enough.

Wind turbines, solar panels and electric cars may be gaining acceptance, but they aren’t growing nearly fast enough to break humanity’s addiction to fossil fuels.

Solving climate change remains a herculean challenge, and the world still isn’t close.

To achieve the goal set by the world’s governments — keeping total global warming well below 2 degrees Celsius (3.6 degrees Fahrenheit) — scientists say that greenhouse gas emissions from coal, oil and natural gas will need to peak within a decade and then rapidly decline to zero well before the end of the century. But the International Energy Agency recently said emissions were still on track to rise for another 20 years.

15,000 million tons oil equivalent

Renewable energy consumption worldwide versus all other fuels

Solar, wind

and other

Hydroelectric

10,000

Natural gas

Nuclear

Coal

5,000

Oil

1965

2018

15,000 million tons oil equivalent

Solar, wind

and other

Renewable energy consumption worldwide versus all other fuels

Hydroelectric

10,000

Natural gas

Nuclear

Coal

5,000

Oil

1965

2018

Source: BP Statistical Review of World Energy

While renewable energy has been growing, that’s been offset somewhat by the decline of nuclear power. And global energy demand keeps growing rapidly, particularly in emerging economies. That means fossil fuel use has continued rising to fill the gap.

To meet the world’s climate goals, experts say, most countries would need to set much more aggressive policies. Those might include taxing carbon dioxide emissions, investing more heavily in clean energy and efficiency, and curbing methane leaks from oil and gas operations.

There have been positive steps. The European Union and California, for instance, have set goals of net zero emissions by 2050.

Nevertheless, China, the world’s largest emitter, has resisted setting a date for zero emissions. And in the United States, the world’s second largest source of carbon pollution, the Trump administration has disavowed action on climate change.

Goodbye, DDT.

Before the first Earth Day, there was the pioneering environmental journalist Rachel Carson. She wrote about the threat of pesticides like DDT in her 1962 bestseller “Silent Spring.”

Beachgoers were sprayed with DDT in a test of the insecticide in 1945.Bettmann/Getty Images

Chemical companies attacked her, but her work helped inspire the first Earth Day: Organizers demanded that DDT be banned, alongside calls for the removal of lead from paint and gasoline. Lead use was common at the time, although there is no safe level of exposure, and children are particularly vulnerable.

In 1972 the newly created Environmental Protection Agency prohibited DDT. A year later, the E.P.A. announced rules to gradually phase out lead from gasoline. The government later tackled other sources of exposure, banning the sale of lead paint in 1978 and lead plumbing in 1986.

Actions like these paid off. Between the late 1970s and 2016, the lead level in the blood of most Americans dropped by nearly 94 percent.

Still, in some parts of the United States, lead in drinking water remains a threat from old pipes still in use. In Flint, Mich., some samples have shown 100 times the level set by the E.P.A. to trigger government response. Similar spikes have occurred in Washington, D.C., and Newark, N.J.

Hello, new chemical health risks.

Those early successes gave way to endless arguments over many other chemicals and whether to restrict them or not.

Congress passed the Toxic Substances Control Act in 1976. President Gerald Ford said the law would provide “broad discretionary authority to protect the health and environment,” and the E.P.A. over time developed a list of 85,000 chemicals in commercial use.

Not all of those are hazardous, of course. But known toxic chemicals like methylene chloride, a paint stripper linked to dozens of deaths, and TCE, a degreaser associated with cancer, have been caught up in battles between regulators and industry over restricting their use.

Why the slow progress? Not only did the law provide little power to the E.P.A. for curtailing toxic chemicals, but courts later enfeebled the agency further. Two years after regulators banned most products that contained asbestos in 1989, a federal appeals court overturned much of the rule.

Congress toughened the law in 2016 when it passed requirements that the E.P.A. evaluate untested chemicals. Under President Trump, however, the E.P.A. postponed long-sought bans on three chemicals used in consumer products that have been tied to inhalation deaths, cancer and birth defects.

The administration also weakened a proposed standard for cleaning up drinking water polluted with the chemicals commonly known as PFAS, and rejected the advice of its own chemical safety experts who in the previous administration had recommended banning the commercial use of the insecticide chlorpyrifos. These are just some of nearly 100 environmental rollbacks under the Trump administration.

The bald eagle soars again.

The California condor. The bald eagle. The Florida manatee.

By the time of the first Earth Day, all these species were facing shocking declines.

In 1967, for the first time, the Interior Department officially listed 78 bird, fish and mammal species as “endangered,” but the agency lacked the authority to protect them.

One of the major legacies of the first Earth Day was a strengthened Endangered Species Act. In 1973, Congress dramatically expanded the law, giving the government more power to restrict activities that could harm at-risk species.

The act has scored some striking successes: More than 1,700 plants and animals have since been protected under the law and roughly 99 percent have avoided extinction. The bald eagle has rebounded impressively in the lower 48 states, going from just 487 nesting pairs in the 1960s to more than 11,000 by 2007 (although the ban on DDT, which had weakened eagles’ egg shells, also gets credit there).

Grizzly bears, gray wolves, whooping cranes and California sea otters have all increased in number since gaining protections.

But there have also been plenty of challenges.

Critics point out that, to date, fewer than 50 species listed under the act have recovered to the point where they no longer need protection. Industry groups and landowners have often argued that the law can impose unreasonable costs on them, while the Trump administration and some Republicans in Congress have pushed to overhaul the act, arguing that it unduly restricts ranching, logging and oil drilling.

And dozens of species have gone extinct while awaiting the sometimes protracted decision on whether they warranted protection.

An extinction crisis looms.

Despite successes in saving individual species from near-extinction, like the whooping crane, the world is still losing natural habitat at an astonishing rate.

Scientists warn that as many as one million plant and animal species could face extinction in the decades ahead, as a result of ever-expanding farming, ranching, logging, hunting, fishing and mining worldwide.

Since 1970, the World Wildlife Fund estimates, the sizes of thousands of different wildlife populations have declined by 60 percent on average. In Indonesia, the replacement of rain forest with palm oil plantations has ravaged the habitat of endangered orangutans and Sumatran tigers. In Mozambique, ivory poachers helped kill nearly 7,000 elephants between 2009 and 2011 alone.

And a new threat has emerged: Global warming is shifting or shrinking the local climates that various creatures and plants have evolved to survive in.

Last year, a comprehensive scientific assessment from the United Nations warned that unless nations step up their efforts to protect what natural habitats are left, they could witness the disappearance of 40 percent of amphibian species, one-third of marine mammals and one-third of reef-forming corals.

The authors of that report noted that the risk to biodiversity has become so severe that piecemeal efforts to protect individual species may no longer be sufficient. They called for “transformative changes” that include lowering consumption, slimming down agriculture’s environmental footprint and cracking down on illegal logging and fishing.

Nature preserves have popped up everywhere.

Around the world, efforts to create vast protected areas have accelerated.

Nations like Costa Rica and Kenya have realized that wildlife refuges can become tourist attractions and moneymakers. In 1992, under the Convention on Biological Diversity, 168 countries vowed to do more; today they have protected more than 15 percent of the world’s land and 7 percent of its oceans by setting up nature reserves and wilderness areas.

At the same time, some countries have had success in returning once-degraded landscapes back to nature. In Europe, woodland areas have increased by roughly 35,000 square miles since 1990, an area the size of Portugal. China has engaged in a major reforestation campaign in recent decades.

Satellite images show that, since 1982, the world has seen a net increase in forest cover.

This year, the nations of the world plan to update the Convention on Biological Diversity. Experts warn that they’ll need to greatly expand protected areas in order to avoid an extinction crisis. That might mean setting aside 30 percent or even fully half of the Earth for nature, although anything remotely approaching that scale would pose big challenges. What about the people who depend on those lands for livelihood?

Meanwhile, the reforestation trend itself isn’t entirely positive. Some of the new forests planted in recent years have far less biodiversity than old-growth forests. What’s more, in some areas forests are expanding because global warming has enabled trees to grow in places they previously couldn’t.

And, of course, tropical rainforests continue to suffer serious declines.

Bulldozers and fires are destroying tropical forests.

Tropical forests are home to at least half of all species on Earth. They are crucial to regulating the planet’s climate.

And they are being cut down at a dramatic rate.

In 2018, about 30 million acres were lost, down only slightly from similar losses in 2016 and 2017. Efforts to slow this have been mixed.

In the Brazilian Amazon, deforestation declined 70 percent between 2005 and 2014 as governments toughened their oversight and farmers found ways to increase their yields without needing to clear more land. And since 2016, Indonesia has worked to slow the spread of palm oil and paper plantations.

But those gains show signs of eroding. Brazil’s leader, Jair Bolsanaro, has pledged to open more of the Amazon to business, and deforestation there is rising again. Indonesia’s recent forest protections have been offset by accelerated loss in Ghana, Ivory Coast and elsewhere.

Scientists say it will be extremely difficult to tame global warming without limiting tropical forest loss. Trees pull carbon dioxide out of the air and store it in their wood and soil. Cutting and burning those trees releases that carbon, warming the planet. By one estimate, tropical deforestation now creates more emissions each year than the entire European Union.

Some countries like Norway and Japan have offered tropical nations billions of dollars to preserve their forests, but progress has been limited. “We’re trying to put out a house fire with a teaspoon,” Frances Seymour, a senior fellow at the World Resources Institute, said in 2018.

Remember the ozone hole? It’s healing.

Four years after the first Earth Day, scientists warned of a new threat to the planet.

The threat came from hair spray.

Gases released by aerosol cans, they said, were “depleting the ozone layer” that envelops the planet and protects against ultraviolet radiation, which can contribute to skin cancer and damage crops.

By 1977 the U.S. government had banned the chemicals in spray cans. But, of course, threats to the ozone layer weren’t only in aerosol cans; chlorofluorocarbons could be found in air conditioners, refrigerators and elsewhere.

Aerosols at a shop in Oregon in 1977.Bettmann/Getty Images

So the spray-can ban wasn’t enough, and by 1985 researchers had discovered a “hole” in the ozone layer. That led to one of the great moments of global environmental unity: The Montreal Protocol, signed by the nations of the world in 1987 to phase out CFCs altogether.

The treaty largely worked. In 2018, NASA said the treaty had led to a sharp decline in ozone depletion, according to years of satellite analysis.

Still, recovery is slow. “Think of it like a patient with a disease,” said Susan Solomon, an atmospheric chemist at the Massachusetts Institute of Technology, in a 2016 interview. Healing takes years as the molecules already in the atmosphere slowly break down.

And people cheat.

Monitoring in 2013 showed that progress was slowing; it seemed that factories in China were likely making more CFCs. But then, last year, the numbers were declining again, suggesting China had cracked down.

The same fix won’t work for climate change.

Nations teamed up to fix the hole in the ozone layer. So why can’t they do the same for climate change?

In other words, why not get all the countries to agree to phase out the greenhouse gases that are warming the planet, much like they did with the CFCs that were creating a big ozone hole?

2019

+1.0°C

Global average temperature difference compared to the middle of the 20th century

+0.5°

–0.5°

1880

1900

1920

1940

1960

1980

2000

2019

+1.0°C

Global average temperature difference compared to the middle of the 20th century

+0.5°

–0.5°

1880

1920

1960

2000

Values are shown relative to the average temperature between 1951 and 1980. Source: NASA Goddard Institute for Space Studies

To some extent, this is what the 2015 Paris climate agreement tried to do. Nearly 200 countries came together to set broad goals for reducing greenhouse gases.

But there are key differences: Unlike the earlier ozone treaty, which set mandatory deadlines for each country to phase out CFCs, the Paris climate agreement allows nations to chart their own course with voluntary goals. Some nations are still struggling to meet even those modest, self-imposed pledges, while President Trump is withdrawing the United States from the agreement altogether.

As it turns out, phasing out greenhouse gases is a vastly more complicated task. By the time nations were ready to ban CFCs, there were readily available substitutes, allowing companies to make relatively easy swaps. By contrast, shifting away from fossil fuels will require transforming how we produce electricity and transport people and goods around the world. It will mean changing how we farm, eat, dress ourselves, build things, and more.

There’s not one simple technological fix. The global economy will need a rethink.

People feared mass starvation. It didn’t happen.

One of the starkest warnings of the 1970s was that there were simply too many people, and not enough food. Widely read books like “The Population Bomb” warned of the collapse of civilization.

Things didn’t turn out that way.

The world’s population has more than doubled since 1970, to nearly 7.8 billion people. Yet the share of people living in extreme poverty has plummeted.

How did the world avoid mass famine? Technology helped. Researchers developed high-yielding crops, and today’s farmers can grow more than twice as much corn, rice and wheat on a given area of land, on average, than in 1970.

Population growth has also slowed. In the 1960s, the world’s population was rising by about 2 percent annually. But as societies get wealthier and better educated, people tend to have fewer kids. Today, the growth rate is about 1 percent per year and falling.

Granted, not all the fears were baseless. As populations have risen, the natural world around us has often suffered, and we are warming the planet at a dangerous pace.

But the conversation has changed dramatically. Fifty years ago, there was mainstream alarm about population growth, which led to sterilization campaigns and other gruesome policies. Today, that message is virtually absent from environmentalism.

Still, resources are limited. Where will food come from?

By 2050, the United Nations projects that the world will be home to nearly 10 billion people, up from “just” 7.8 billion today.

One of the big challenges will be to keep feeding everyone without further damaging the natural world. That’s a daunting task.

Already, global food production occupies about half of all habitable land, generates about one-quarter of humanity’s greenhouse gas emissions and is a major factor behind the decline of biodiversity worldwide. If farmers continue meeting growing demand by clearing forests and other ecosystems, as they’ve done in the past, it would transform an area twice the size of India. That, in turn, could make it impossible to keep climate change in check.

Making things tougher, global warming is expected to put new stress on crops and reduce water supplies in many countries.

One recent study by the World Resources Institute found that it’s technically possible for the world to keep feeding everyone by 2050 without vast ecological destruction. But doing so would require a sweeping shift in agricultural practices — involving everything from developing new technologies to simply wasting less food. How much is wasted? In the United States, about one-third of the food supply, according to the federal government.

Environmentalism is now in the DNA of American politics.

The first Earth Day was a defining moment in the great American experiment. Twenty million people nationwide — at the time, roughly one in 10 citizens — took part.

Earth Day in New York City, 1970.Bettmann/Getty Images

You can see the descendents of Earth Day activism today in protests over fossil fuel infrastructure like the Dakota Access Pipeline at Standing Rock, or in the support for people like Greta Thunberg, the Swedish teenager who last September helped inspire millions of people to march worldwide in protest of climate change.

Last year the Pew Research Center reported that nearly 70 percent of Americans said the government was not doing enough to protect the water quality of lakes, rivers and streams, or to protect air quality. And this year, Pew reported that, for the first time in two decades, a majority of Americans believed dealing with climate change should be a top priority for the president and Congress, a 14-point rise from just four years ago.

Yet it seems we’re more divided than ever.

In the 1970s, environmentalism was overwhelmingly bipartisan.

Democrats and Republicans worked together to create the Clean Water Act, the Clean Air Act and the E.P.A.

Today that kind of teamwork seems all but unthinkable. While research by Pew shows that voters’ interest in climate and environmental issues is soaring, it also reveals an astonishing split: More than 75 percent of Democrats called climate change a top policy priority, while less than 25 percent of Republicans did.

Fossil fuel companies and political donors have funded denial of the overwhelming evidence for climate change, and the message has been successful with conservative politicians and voters. The Trump administration is trying to roll back regulations around climate change as well as broader environmental measures.

Still, there are some signs the split isn’t as intractable as it seems.

Renewable energy sources like wind and solar have been embraced in red states as well. Disasters fueled by climate change, such as flooding and wildfires, are forcing politicians to confront the reality of global warming. And voters are noticing: According to the Yale Program on Climate Change Communications, majorities of people surveyed in every congressional district in the country say that climate change is occurring.

But perhaps the simplest reason to think the partisan divide could soften may be the younger generation. Some 52 percent of Republicans between 18 and 38 feel the government is doing too little on climate, Pew said last year, making the issue an electoral time bomb for the party.

Whether that leads to a revival of bipartisan environmentalism is yet to be seen. For now, the coronavirus pandemic could well reshape national priorities for a time. But when that disaster has passed, the fact remains: We’re warming the world and without forceful action, the crisis will get worse.