Quantcast

Arctic Laughing Gas Emissions Could Accelerate Global Warming

Climate
NASA scientists flew over the Kuskokwim river in southwest Alaska in 2017 to investigate how water levels in the Arctic landscape change as permafrost thaws. Peter Griffith, NASA

By Tim Radford

Scientists have identified yet another hazard linked to the thawing permafrost: laughing gas. A series of flights over the North Slope of Alaska has detected unexpected levels of emissions of the greenhouse gas nitrous oxide from the rapidly warming soils.


Nitrous oxide, which chemists know also as laughing gas, is an estimated 300 times more potent as a climate warming agent than the principal greenhouse gas, carbon dioxide. It was present in data recordings at levels at least 12 times higher than all previous estimates.

And it is long-lived: it survives in the atmosphere for around 120 years, according to a separate new study of the microbiology of nitrous oxide. And if it gets even higher, into the stratosphere, it can be converted by the action of oxygen and sunlight into another oxide of nitrogen, to quietly destroy the ozone layer.

Oxides of nitrogen are at least as damaging to stratospheric ozone — an invisible screen that absorbs potentially lethal ultraviolet radiation from the sun — as the man-made chlorofluorocarbons banned by an international protocol three decades ago.

Nitrogen is an inert gas which makes up almost four-fifths of the planet's atmosphere. It is vital to life: growing plants build their tissues by absorbing carbon dioxide from the atmosphere with the aid of photosynthesis. But they must also absorb nitrogen from plant decay and animal waste, through their roots, with help from soil microbes.

The process is natural, but too slow to help deliver the cereals, tubers and pulses needed to feed seven billion humans and their livestock. For more than 100 years, nations have been making nitrogenous fertilizer in factories and applying it generously to soils to boost harvest yields.

As a consequence, nitrous oxide is now the third most significant greenhouse gas, and the news that it is rising from the permafrost could be troubling.

The permafrost is home to enormous stores of carbon: as soil microbes become warmer and more active, they start to break down long-frozen and partly-decomposed plant material to release both carbon dioxide and potent quantities of methane. The implication is that nitrous oxide could add to the mix, and accelerate warming still further.

Study's Revelation

"Much smaller increases in nitrous oxide would entail the same kind of climate change that a large plume of CO2 would cause," said Jordan Wilkerson, a Harvard graduate student who led the research, now published in the journal Atmospheric Chemistry and Physics.

"We don't know how much more it's going to increase and we didn't know it was significant at all until this study came out."

The research is based on data collected from a series of low-level flights over four different areas of the North Slope of Alaska, and the scientists used a routine technique to determine the balance of gases getting into the atmosphere from what had once been permafrost.

The point of the flights was to measure levels of carbon dioxide, methane and water vapor, but the raw data included information about nitrous oxide as well: information recovered and examined only years later.

Arctic in Change

The weight of the finding is uncertain. One-fourth of the northern hemisphere is home to permafrost — 23 million square kilometers (approximately 8.9 million square miles) — and the flights covered only 310 square kilometers (approximately 120 square miles) in all, and only in the month of August. What could be true for one part of the frozen landscape may not apply to all of it.

And thanks to global warming driven by fossil fuel emissions from the world's power stations, vehicle exhausts and factory chimneys, the Arctic is changing.

Shrubs and trees are beginning to invade the frozen north. Green things consume nitrogen, and the greening of the Arctic might actually decrease nitrous oxide emissions.

Once again, the study is a reminder of how much more work is needed to understand the chemistry, biology and geophysics of climate change.

Reposted with permission from our media associate Climate News Network.

EcoWatch Daily Newsletter

A new study shows that half of all Arctic warming and corresponding sea-loss during the late 20th century was caused by ozone-depleting substances. Here, icebergs discharged from Greenland's Jakobshavn Glacier. Kevin Krajick / Earth Institute / EurekAlert!

The world awakened to the hole in the ozone layer in 1985, which scientists attributed it to ozone depleting substances. Two years later, in Montreal, the world agreed to ban the halogen compounds causing the massive hole over Antarctica. Research now shows that those chemicals didn't just cut a hole in the ozone layer, they also warmed up the Arctic.

Read More
Diane Wilson holds up a bag full of nurdles she collected from one of Formosa's outfall areas on Jan. 15. Julie Dermansky / DeSmogBlog

By Julie Dermansky

On the afternoon of Jan. 15, activist Diane Wilson kicked off a San Antonio Estuary Waterkeeper meeting on the side of the road across from a Formosa plastics manufacturing plant in Point Comfort, Texas.

After Wilson and the waterkeeper successfully sued Formosa in 2017, the company agreed to no longer release even one of the tiny plastic pellets known as nurdles into the region's waterways. The group of volunteers had assembled that day to check whether the plant was still discharging these raw materials of plastics manufacturing.

Read More
Sponsored

By Simon Coghlan and Kobi Leins

A remarkable combination of artificial intelligence (AI) and biology has produced the world's first "living robots."

Read More
Malaysian Environment Minister Yeo Bee Yin (front 2nd L) and officials inspect a container containing plastic waste shipment on Jan. 20, 2020 before sending back to the countries of origin. AFP via Getty Images

The Southeast Asian country Malaysia has sent 150 shipping containers packed with plastic waste back to 13 wealthy countries, putting the world on notice that it will not be the world's garbage dump, as CNN reported. The countries receiving their trash back include the United States, the United Kingdom, France and Canada.

Read More
Trump leaves after delivering a speech at the Congress Centre during the World Economic Forum annual meeting in Davos on Jan. 21, 2020. JIM WATSON / AFP via Getty Images

U.S. President Donald Trump dismissed the concerns of environmental activists as "pessimism" in a speech to political and business leaders at the start of the World Economic Forum (WEF) in Davos on Tuesday.

Read More