Wednesday , December 2 2020

Scientists dig deeper into the missing parts of the climate puzzle.



"Every time we processed the sample, it was a terrible thing. It is only a mistake to commit a week's devastation."

Indeed, the results of a six-year project led by CSIRO atmospheric scientist David Etheridge and Vas Petrenko of the University of Rochester, USA, can be measured on their own according to how they are found.

The role of carbon dioxide, the primary greenhouse gas, has been known for over a century, including how it is absorbed by marine or terrestrial plants and removed from the atmosphere.

However, it is not known what actually happened to some 40 other gases, including methane, hydrofluorocarbons and ozone-depleting chemicals, over decades after industrialization.

"How do we know? [these gases] Will be produced. We need to know how quickly they are removed. "Etheridge speaks at Melbourne's warmer borders this week.

"Without that, we only got a part of the puzzle that is part of the equation."

This is the problem.

We see that hydroxyl radicals that combine oxygen and hydrogen act like a scrubber in the atmosphere, destroying non-CO2 greenhouse gases such as methane.

Ice core drilling station at Law Dome, 120km inland from Casey Station.

Ice core drilling station at Law Dome, 120km inland from Casey Station.credit:AAP

The gases contribute about one third of the additional warming we do on Earth by capturing additional heat from the sun in our atmosphere.

The hydroxyl is naturally produced in the atmosphere but is reactive, so it takes only about one second before destroying the contaminant molecule.

"Hydroxyl is so variable that it has a short life span and is so versatile in time and space that it is actually difficult to measure it in modern settings."

More importantly, there is little concept of whether this major detergent has increased or decreased abruptly since pre-industrial times, and there is implication for future emissions.

Oxidation processes involving hydroxylation are actually important to maintaining methane in its support role, rather than being the main whistle to warm the atmosphere, "says Nep.

This result may mean that a major climate model backlash is needed to support the Paris Climate Convention, which depends on the outcome, but is in almost 200 countries.

"all [the models] And assumes fundamental reactivity. [of hydroxyl in] The atmosphere before 1990, "said Neff." This is the first real check on some of the models. "

Making the check is not easy, he says, and includes more than a strange "touching moment."

The ambitious cuts made three years ago by CSIRO executives brought in a day after the slaughter of the entire project next week. Due to popular pressure at home and abroad, many scientists have been saved, including this project.

Recently, she had physical difficulties, often coping with cold, cold weather, falling below 20 degrees Celsius, and heavy snowfall at Law Dome, 120 kilometers east of Casey's Antarctica in Australia.

Etheridge has been involved in atmospheric studies for decades and knows that Law Dome has the special characteristics that scientists need. In particular, this site is where the heaviest snow falls everywhere.

"Snow is declining to an average of about 10 times in Antarctica, from five to six centimeters a year," Neft said. "Ice is buried much faster than anywhere else."

Drilling of ice cores to analyze air trapped in compressed snow has been commonplace for polar ice scientists for decades. However, in the case of hydroxide hunting, such air samples are especially important.

David Etheridge and colleagues working in a blizzard at the Law Dome.

David Etheridge and colleagues working in a blizzard at the Law Dome.

Researchers will not find radical compounds because hydroxyl groups are not stored in containers for any length of time. Rather, scientists are studying proxy molecules (carbon-14 isotopes of carbon monoxide) that indirectly reveal the past existence of hydroxyl groups.

Carbon-14 is produced by reaction to spacecraft from outside the solar system, but Law Dome's heavy snow acts like a "shield of X-rays".

The snow then protects the air in deeper ice so that carbon 14 is not generated by cosmic rays when compared to the original amount in space.

Nep says there is no better place to drill.

"This is the only place in the world where we can get a lot of clean air that is not damaged by this carbon-14 aspect we are looking for," he says.

Of course, getting the evidence is not nearly skiing in the back country.

Scientists typically sleep in a mountaineering tent in a winter sleeping bag in summer. When snow falls, it becomes increasingly difficult for employees to fight snow drifts.

The crew worked for about 77 days to extract about 5 tons of ice and complete six drilling operations. With an average of three in-depth drills, scientists were able to collect ice around 1875.

It must be fast enough to understand the air condition before the greenhouse gas surges. For example, methane emissions have increased by about 200% since the late 1880s.

In a tent with an ice core.

In a tent with an ice core.credit:Joel Pedro

Humans have also released many industrial chemicals with varying abilities to warm the earth, affect the stratospheric ozone layer, and contribute to local pollution at that time. All of these materials can increase the wash load of hydroxyl There is.

Despite this delicate experiment, drills can not use drill fluids that can get deeper into the 1750s when the industrial age began.

Sensitivity to possible contamination extends to placing a wind-blown side-basically altered shipping container – of about 50 meters of another building in a science building tent to avoid contamination of the camp's diesel generator.

The work may not be serious because the ice needs to be processed immediately and keeps the purity of the core as high as possible, which requires extraction.

"They are like hot potatoes and suddenly they are on the surface and are being bombarded by the entire beam of space," Neff says.

Thousands of kilometers of ice are not sent to distant laboratories, and the main evidence is stored in stainless steel tanks. Approximately 20 people, each weighing approximately 10 kilograms, visit Casey and travel until the camp is over.

Neph, a geologist, also said the study was better than expected.

"We have everything we want perfectly," he said. "All of these samples are absolutely perfect and clean than we thought."

However, at least one year of testing is waiting, including the ANSTO nuclear facility at the southwest border of Sydney.

Etheridge Sun Herald and Sunday era Last week, CSIRO's world-famous air archives tours in Aspendale, Melbourne's Sandbelt, have a feeling of "hurting" that hydro-richness will appear on skids.

"In my reading of evidence and chemistry, I expect to see a decline during the industrial period of hydroxyl, I expect it to decrease," he stressed, noting that the results of the current project have not been tested.

"I am looking forward to being found wrong."

This discovery will be reinforced by similar work in the Northern Hemisphere. For example, it seems to excavate the ice sheet of Greenland, whose core may be much dirtier than the Antarctic.

Nevertheless, the significance of demonstrating that the ability to destroy methane has diminished (now lives for about 10 years) – will be profound depending on the scale of the decline.

In addition to increasing the warming potential of methane from coal mines and natural gas fields, the possibility that hydrogen can be used as a "clean fuel" may also be questionable. (The Labor Party announced a $ 1 billion plan this week to help create a hydrogen export area, driven by a massive increase in renewable energy in Queensland.)

"Hydrogen is a very leaking molecule and we have to expect a slight leak in yield," he said. He added that hydrogen itself has a greenhouse effect.

"It does not really matter, but we do not know."

While Neff is away from his family for 100 days, it is hard work, but I am proud that his research is proceeding to answer the greatest questions of climate science.

"We do not want to be blind. [about] What is the impact on the entire system of the earth?

Etheridge likens his team's research to space exploration and collects information that scientists have proved useful for something unexpected later on.

He noted that CSIRO and other scientific institutions began warning climate change in the 1980s, which was long before the warming signal became more evident than the background noise of natural fluctuations.

"Signals are everywhere now," he says.

"We are dealing with a $ 1 trillion question, whether we're going to leave the atmosphere, take care of business as usual, or care about the planet, or reduce emissions.

"We are trying to manage this question with a million dollar science.

Peter Hannam writes about the environmental issues of The Sydney Morning Herald and The Age.

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