Scientists warn that the melting Arctic could lead to uncontrolled heating | Climate Crisis News

Scientists are increasingly warning that the melting Arctic may push the planet into a vicious cycle of uncontrolled heating, because the massive carbon storage in the melting ground releases powerful greenhouse gases.

For thousands of years, permafrost—the ground that has been frozen for two consecutive years or more—has locked dead plant and animal matter in deep freeze under the tundra. In total, these ancient remnants have an estimated 1,600 billion tons of organic carbon, almost twice the amount currently found in the Earth’s atmosphere.

This frozen vault covers a quarter of the northern hemisphere and is melting due to rising temperatures, widespread wildfires and unprecedented heat waves in Siberia and other extreme northern regions. In turn, this turns the Arctic carbon sink into a source of greenhouse gases.

Among these gases, methane is a gas. In 100 years, its ability to absorb heat in the earth’s atmosphere is 34 times that of carbon dioxide (CO2). In 20 years, its effectiveness can be increased by 86 times.Then there is nitrous oxide-its warming potential is roughly 300 times Carbon dioxide emissions over 100 years.

This is forming a dangerous feedback loop-human activities such as burning fossil fuels and raising livestock warm the atmosphere, causing the permafrost to melt and release additional greenhouse gases.

This will lead to further warming, further thawing and further emissions, and may bring about the most serious impact of climate change at a much faster rate than expected.

“Because of the scale of warming we are seeing in the Arctic, this may accelerate,” Rachael Treharne, an Arctic ecologist at the Woodwell Climate Research Center, told Al Jazeera that she studies thawing permafrost and The impact of wildfires on climate change. .

“We are already considering irreversible changes.”

These warnings were issued before the UN Climate Change Conference, or COP26, Regarded by many as the last chance to avoid global environmental disasters.

The meeting may veto plans to reduce carbon emissions, which will be held in Glasgow, Scotland from October 31st to 12th.

“We can’t control nature”

The Arctic has heated to more than 2 degrees Celsius (3.8 degrees Fahrenheit) above the pre-industrial average, and the temperature is on the rise.

Due to the rapid disappearance of sea ice, the heating rate of these northern latitudes is more than twice the global average, and the highly heat-absorbing blue-black seawater replaces the highly reflective white surface.

Scientists are shocked that the higher temperatures conducive to the melting of permafrost are about 70 years earlier than predicted.

The pollution potential of permafrost begins when the thawed ground is moist and warm, and microorganisms begin to produce carbon dioxide or methane because they decompose organic matter in swamps and once hard soil.

Thawing the bedrock further complicates this problem. As temperature rises and pressure changes, the frozen deposits of methane and other hydrocarbons naturally present in the permafrost become gases, which may be released into the atmosphere through cracks.

“We can more or less control the burning of fossil fuels through political decisions and economic regulations,” said Dmitry Zastrozhnov, a lecturer and geologist at the Institute of Earth Sciences at St. Petersburg State University who is studying methane release from the limestone regions of Siberia. .

“But we cannot ask permafrost to stop releasing methane. We cannot control nature.”

Scientists have also detected the accelerated release of these powerful greenhouse gases in the Arctic Ocean off the coast of Siberia in northern Russia.

Crystals called hydrates consist of methane gas molecules trapped between solid water molecules and collapse as the temperature rises. These are then discharged into the atmosphere after reaching the surface as bubbles.

‘Suddenly defrosted’

The increasing frequency and severity of wildfires in the Arctic and northern regions emit large amounts of carbon—not only from burning, but also by further thawing permafrost.

Last year, these unprecedented fires released 35% more carbon dioxide than in 2019, which in itself set a record high for Arctic wildfire emissions.

These fires occurred during the record-breaking Siberian heat wave, with temperatures reaching 38 degrees Celsius (104 degrees Fahrenheit)-the highest temperature on record in the Arctic Circle-more than a century ago, this small town recorded the coldest ever recorded in the northern hemisphere temperature. At the same time, Arctic sea ice has shrunk to the second lowest level on record.

A series of processes collectively referred to as “sudden thawing” exacerbated these problems, causing the geomorphology to scar the Arctic landscape.

The melting of ice-dense permafrost will cause gradual sinking and even large-scale ground collapse, which will further melt the deep permafrost and release more carbon into the atmosphere.

Discovering the rate and amount of permafrost melting is the key to understanding the need to reduce anthropogenic emissions. A paper A study published in 2018 found that compared with gradual thawing, sudden thawing can increase the release of ancient carbon by 190%.

“We don’t have to wait 200 or 300 years to get this massive amount of released permafrost carbon,” said Katey Walter Anthony of the University of Alaska, who led the research. “In my lifetime, in the lifetime of my children, it should get better and better.”

“Humanitarian Crisis”

Earlier this year, The researchers warned These gas emission processes are not fully considered in global forecasts-which means that these forecasts may be too low, making it more difficult for the world to contain climate change.

This greatly reduces the amount of greenhouse gases that humans can emit to limit global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels, a key goal of the 2015 Paris climate agreement.

The authors of the study said: “There is an urgent need to incorporate the latest science on permafrost melting and carbon emissions from northern wildfires.”

The problem is that these processes are extremely complex and occur in one of the largest and most remote areas in the world. Better review and collaboration are key.

Geologist Zastrozhnov said: “We need to invest more money in the monitoring system and combine all the efforts of different disciplines to better understand and model.”

In addition to global influence, 4 million people live in the Arctic. These local communities are at the cusp of a constantly changing landscape, facing more landslides, waterway disruptions and infrastructure damage.

Mercury seeps into rivers from the melting permafrost and accumulates in the food chain. As the earth gave way, the oil depot leaked. Communities endure displacement while causing severe damage to traditional food sources-this is the key to the well-being of the indigenous people who have coexisted with this unique habitat for thousands of years.

“We see a humanitarian crisis,” Trehahn said. “The ground really collapsed under their feet. We underestimated the urgency of what we need to do.”

Although carbon capture facilities are expected to eliminate emissions from the atmosphere—even the rewilding of ice age ecosystems to reduce freezing—experts say that one solution is better than all others.

“Defrosting permafrost is like a large truck that is gaining power-it has a braking distance,” Trehahn said.

“Even if we reduce warming, permafrost will still respond to peak temperatures and emit carbon. If we want to minimize carbon emissions from permafrost, we must now reduce global emissions.”



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