Posted on 9 June 2020 by Guest Author

This is a re-post from Yale Climate Connections by Daniel Grossman

The coronavirus pandemic still has a long way to go, despite widespread claims to the contrary, and the COVID-19 virus has already killed at least 300,000 people from all around the globe, about one-third of those fatalities just in the U.S.

There’s a widely reported direct relationship between the onset of this plague and the glimmer of good news concerning another global crisis also gathering force, climate change: The widespread stay-at-home practices that have slowed the virus have also led to a clearing of the air. Slowed vehicle, airplane, and ship traffic and decreased factory production have led to drops in air and water pollution worldwide.

As fellow YCC regular contributor Karin Kirk explained on this site last month, the International Energy Agency, IEA, has just forecast that carbon dioxide emissions emitted from the world’s smokestacks and tailpipes are projected to plunge by 8% this year. IEA predicts that the pandemic will remove 10 years of emissions growth practically in the blink of an eye, a drop bigger than at any point since World War II.

This development brings up a recurring question: Is it possible that this temporary but dramatic pandemic-related reduction will actually slow climate change? As always, it’s complicated. But spoiler alert: the short answer is no, unless a new awareness of humanity’s global fragility takes root. Researchers say the concentration of carbon dioxide in the air will rise to a record-high level this month, higher than it’s been in human history. Higher than it has been since the Pliocene, millions of years ago. And this year had the second-warmest first quarter ever recorded.

Anomaly on Mauna Loa in Hawaii

In mid-March this year, Kristopher Karnauskas reported an anomaly in the daily stream of carbon dioxide measurements made at the Mauna Loa Observatory in Hawaii. Research outposts like that in Mauna Loa, far from cities, sample air as free of transient local influence as possible, capturing a near-pristine record of the worldwide average concentration of globally consequential gases, such as carbon dioxide, methane, and chlorofluorocarbons. Karnauskaus, a climate researcher at the University of Colorado, noticed the station’s measurements had departed slightly from that season’s normal trajectory. Only once before in 60 years of measurements had carbon dioxide risen so little in the first several weeks of the year.

Karnauskas wondered: Could this be the global signal – lagging a few weeks – of China, responding to the epidemic, putting its economy into a medically induced coma? After all, China’s use of oil and coal had plummeted in early February. Lauri Myllyvirta, an analyst at the British climate publication Carbon Brief estimates that during the two middle weeks of February, China, for some time the world’s largest producer of carbon dioxide pollution, pumped out only 75% of its normal output of the gas.

The Mauna Loa Observatory, on Hawaii’s Big Island, has recorded the world’s longest continuous set of carbon dioxide measurements. A renowned Scripps Institution chemist, Charles Keeling, began studying carbon dioxide levels there in 1958. After two years, he concluded that the annual average concentration was rising, a change he thought – correctly, we now know – was caused by the burning of oil, coal, and natural gas. Through the decades that followed, Keeling’s ground-breaking research revealed the famous exponentially-rising sawtooth curve of carbon dioxide which has since been named after him, the “Keeling curve.” The cycle of the seasons creates a regular pattern of small fluctuations in the otherwise-upward trajectory. It’s as if the planet is breathing in and out once each year. Plants soak up carbon dioxide in the Northern Hemisphere spring and summer. Then vegetation hibernates, halting uptake and producing a steep drop each fall and winter.

The sensitive measurements made on Mount Mauna Loa have previously registered large-scale economic events, such as the Great Recession of 2008 and the economic rebound that followed it. By late March of this year, Karnauskaus thought he might be seeing such a rebound. Mauna Loa’s daily readings of atmospheric concentrations had snapped back to regular levels. He tweeted that this might show China’s economy waking back up. Other climate scientists call the aberrant measurements unremarkable natural variations. Ralph Keeling, the son of Charles, like his father a professor at the Scripps Institution of Oceanography in La Jolla, Ca., says, “At this point, we don’t see any deviation from what we might expect.” He says small deviations in prevailing winds can alter the blend of air reaching the sensors, slightly changing the amount of carbon dioxide detected at the mountain observatory. Changes in volcanic activity or abnormal weather conditions influencing forest growth also cause such transient carbon dioxide concentrations.

Examining and learning from historic disease outbreaks

The idea that the pandemic could alter the atmosphere is by no means fanciful. In 2003, paleoclimatologist William Ruddiman proposed that disease outbreaks – occurring between 150 and 700 AD, in the mid 1300s AD, and between 1500 and 1800 AD – explain curious dips in carbon dioxide concentration discovered in ancient air bubbles preserved within glacier ice cores. Ruddiman proposed that farms, abandoned by disease victims, reverted to forest, which then absorbed extra carbon dioxide from the atmosphere.

Ruddiman’s theory got a boost in 2019. A research team at University College London meticulously reconstructed the atmospheric impacts of the European conquest of the Americas (sometimes called The Great Dying), beginning in 1492. It has long been known that colonizers from England, Spain, France, and other superpowers of the time, unleashed a microbial death squad infecting non-Europeans with smallpox, measles, influenza, the bubonic plague, malaria, diphtheria, typhus, and cholera. It is also generally understood that the invasion devastated a population naïve to the European plagues. But the climate impact of the slaughter has gotten attention only in the past few years.

Top U.N. official asks if green economic recovery measures could ‘do things right for the future.’

Recent decades of historical research reveal that North America and lowland South America were not so sparsely populated as the Europeans’ “discovery of the New World” shibboleth supposes. Building on this work, the University College London group estimates that 60.5 million people lived in the Western Hemisphere before Europeans invaded. Last year, the researchers published a paper in the journal Quaternary Science Reviews, calculating that within 100 years this population shrunk by 90% to only 6 million people. They suggested that an area the size of France reverted from farmland to natural vegetation, including vast tracts of the present-day Amazon jungle, pulling 30 billion tons of carbon dioxide out of the atmosphere. The entire planet cooled by 0.14 °F, they say, intensifying the Little Ice Age, the coldest period in the past 8,000 years.

Carbon dioxide emissions down today … but what about tomorrow?

The current pandemic has swiftly slashed the amount of carbon dioxide we humans inject into the air. According to the IEA, global car and truck travel has halved. Global air travel is down by almost 75%. By the end of the year, the world will have burned 8% less coal and 9% less oil than had been expected, according to IEA’s latest forecast, released in April.

Still, it may surprise some to learn that this pandemic won’t decrease the concentration of carbon dioxide in the atmosphere and it won’t lower global temperatures. The effect will not be at all like that from the Great Dying, says Alexander Koch, lead author of the Quaternary Science Reviews paper. Back then, wind moved ships, the sun dried clothes and water wheels cranked sawmills. Humanity then influenced the atmosphere by cutting forests down, not by burning fossil fuels. And while a small preindustrial population can cut only so much wood, the quantity of fossil fuel that today’s global population approaching 8 billion could burn is virtually limitless.

A one-year drop by 8%? What about a decade of annual drops?

Since industrialists began shoveling coal into boilers in the late 1800s, the amount of carbon dioxide added to the atmosphere each year has grown exponentially. The scientific confirmation of the existential threat of climate change has done little to flatten this curve. Although IEA projects the pandemic will reduce global carbon dioxide output this year by 8%, back to the level in 2010, the United Nations’ 2019 Emissions Gap Report takes a longer-term view: It calculates that avoiding warming of more than 1.5 degrees Celsius above the pre-industrial temperature will require an unrelenting reduction of nearly 8% every year for the next decade.

There’s no evidence that such a reduction will occur. Barring stringent new international climate policies, emissions growth in time will resume its prior fateful climb as populations’ mobilization increases and economic recovery builds. “People’s cars are parked on the driveway. Planes are not flying anymore. Offices are closed,” says Simon Evens, deputy editor of Carbon Brief. “But the car, it is still the same car. The plane is still the same plane. The factory, once it opens, will have exactly the same emissions.”

Ralph Keeling of Scripps is more hopeful. He says that weeks of quarantine could instill long-lasting changes beneficial to the climate, such as increased telecommuting. “The big question is what kind of trajectory do we come out on? Are we going to be reinforcing behaviors that allow us to keep emissions low while bringing our economy back?”

Many activists and global leaders are calling on the world to turn the pandemic into an unbidden opportunity to fight climate change. In a video communique on Earth Day, Antonio Guterres, secretary general of the United Nations, called on nations to combat job losses and failing businesses with green investments that favor climate-friendly industries over the fossil-fuel-intensive status quo.

“We need to turn the recovery into a real opportunity to do things right for the future,” Guterres urged.