Arctic Warming: Some Effects May Remain Irreversible Despite Reduced Carbon Dioxide Levels

Birth near the Heisinger Glacier in Greenland

Glacier meets sea at Dixon Fjord in Greenland

Jane Rix/Alamy

Even if atmospheric carbon dioxide returns to pre-industrial levels and the global temperature decreases, the Arctic is projected to warm by approximately 1.5 degrees Celsius.

It is also expected that the region will receive about 0.1 millimeter of extra precipitation daily, regardless of the implementation of large-scale carbon dioxide removal (CDR) strategies.

“These findings emphasize the irreversible aspect of climate change in the Arctic, even with aggressive CDR efforts,” the researchers stated in their publication.

Current atmospheric CO2 levels are roughly 1.5 times greater than pre-industrial levels, resulting in a warming of 3°C or more. A study published in March revealed that even if extra carbon dioxide were removed, sea ice coverage would still average 1 million square kilometers less.

In a new investigation, researchers led by Xiaodong from the Institute of Atmospheric Physics in Beijing utilized 11 distinct climate models to assess the likelihood of continued Arctic warming. The findings also indicate that precipitation is likely to increase, according to Michael Meredith from the British Antarctic Survey, who was not part of the study.

The primary reason for this persistent warming is that oceans, which have absorbed 90% of the heat from global warming, will continue to warm the Arctic for centuries, even when atmospheric temperatures decrease. This situation will likely be amplified by feedback mechanisms, such as diminishing sea ice, which causes the open ocean to raise air temperatures.

“Even if the atmosphere continues to cool, the oceans will lag behind and counteract this trend,” Meredith remarked.

Many experts express skepticism about whether CDR methods, including tree planting and mechanical CO2 extraction, can significantly lower atmospheric CO2 levels due to the financial and energy challenges, a process that could take thousands of years.

Dong et al. examined a theoretical scenario where atmospheric CO2 levels quadrupled from pre-industrial amounts over 140 years, decreased for another 140 years, and then remained at pre-industrial levels for 60 additional years.

The study also reviewed two potential real-world climate scenarios: one in which humanity immediately reduces emissions, and another where emissions remain high but CDR efforts ramp up quickly starting in 2070. In these scenarios, similar to the theoretical model, the Arctic was found to be approximately 1.5 degrees Celsius warmer with precipitation increasing by an additional 0.1 mm per day by 2100.

The models forecast a decrease in temperatures and precipitation in the waters just south of Greenland and Iceland, contrasting with other regions in the Far North. This suggests a decline in the Atlantic Meridional Overturning Circulation (AMOC), which is responsible for transporting warm surface water from the tropics to this area. This current is already weakening as global ocean temperatures rise, a trend that might lead to colder winters in Europe over time.

Climate-related effects, such as thawing permafrost and melting of the Greenland ice sheet, are likely to persist but were not included in this study’s models.

“The Greenland ice sheet is expected to behave as observed, meaning it will continue to lose mass and contribute to sea level rise,” stated Mark Selles from the US National Snow and Ice Data Center.

While the study indicates that the Arctic will remain warm for centuries, it is anticipated that it will eventually cool over the course of many more centuries or even millennia.

topic:

  • climate change/
  • arctic

Source: www.newscientist.com

Gene Editing Offers Hope for “Irreversible” Kidney Disease Damage Treatment

Kidney disease can result in hypertension and infections

Mohammed Haneefa Nizamudeen/Getty Images

Recent animal research suggests that damage caused by the most prevalent hereditary kidney disease may not be as irreversible as previously thought. Researchers are using CRISPR gene editing to potentially reverse certain mutations responsible for the condition.

Polycystic kidney disease (PKD) gradually alters kidney function, leading to debilitating effects. “It was generally believed that correcting the mutations would not change the outcome,” says Michael Kaminski from Berlin University of Medicine.

PKD results in the formation of fluid-filled cysts in the kidneys and liver, leading to organ failure and necessitating dialysis or transplants. Besides organ failure, damage and swelling can lead to other severe issues, including high blood pressure and infections.

The disease typically affects adults, with approximately 12 million individuals globally estimated to be affected. Symptoms may not manifest until the cysts reach significant size in one’s 30s, by which point there may already be extensive damage to the kidneys and liver.

Kaminski’s team has utilized a CRISPR method known as base editing to correct mutations in the PKD1 gene in mice models.

This technique successfully corrected mutations primarily in the liver, resulting in a reduction in both the size and number of cysts post-treatment. Kaminski noted potential improvements in the kidneys as well.

Specifically, Xiaogang Li’s team at Mayo Clinic conducted a similar study using more precise methods targeting the kidneys, indicating a reduction in cyst size and quantity, according to Li.

Both teams employed viral vectors to deliver gene-editing tools, which poses challenges with repeated doses due to immune responses might hinder treatment. “This is a legitimate concern,” Li notes. “However, we’ve observed limited immune responses in our animal models so far.”

Utilizing lipid nanoparticles instead of viral vectors, as seen in mRNA vaccines, could mitigate immune-related issues, but Kaminski warns that these particles may struggle to penetrate deeply into the kidneys through the bloodstream. “I believe that the delivery method using [lipid nanoparticles] might become more feasible through urinary pathways,” he says.

Another limitation is that base editing primarily addresses single-character mutations, rendering it ineffective for individuals with longer mutation sequences. However, Li reports successful outcomes using a technique known as Prime editing.

These findings are poised to be published shortly in scientific journals, with plans for human trials to follow. “After our publication, I aim to organize a small clinical trial,” he states.

The broader implications of this research suggest that if PKD can indeed be reversed, it could ignite more research into this potential therapeutic avenue. Currently, the only approved treatment is tolvaptan, which only slightly slows disease progression and requires significant fluid intake.

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Source: www.newscientist.com

New Study Shows Common Kitchen Worktop Material Can Lead to Irreversible Lung Disease

Doctors are calling for a ban on artificial stone, a popular material used for kitchen worktops, following the confirmation of eight cases of artificial stone silicosis in the UK for the first time.

Also known as engineered or reconstituted stone, artificial stone has gained popularity for its aesthetics and durability over the last two decades. However, a new report published in the British Journal of Construction highlights the serious health risks posed by its high silica content, which exceeds 90% compared to 3% in marble and 30% in granite.

“Silicosis is a progressive lung disease caused by inhaling crystalline silica dust,” said Dr. Patrick Howlett, a spokesperson for BBC Science Focus. “The risk of developing silicosis is significantly higher for workers in the artificial stone industry compared to those with chronic respiratory conditions.”


“Various industries expose individuals to silicosis, including mining, pottery, cement work, and now artificial stone fabrication. Prolonged exposure to low levels of silica dust can lead to the development of silicosis over time,” added Dr. Howlett.

All eight affected individuals were male, with an average age of 34, and most worked for small businesses with fewer than 10 employees. Poor safety practices, such as inadequate respiratory protection and ventilation systems, were reported by workers during cutting and grinding operations.

The report’s authors emphasized the need for national guidelines and better enforcement to protect workers from artificial stone silicosis. They highlighted the urgent need for early detection of cases and preventative measures to avoid a potential epidemic.

Since 2010, cases of artificial stone silicosis have been reported worldwide, but the UK confirmed its first cases in mid-2023. California has identified nearly 100 cases of silicosis among countertop workers, prompting the adoption of new regulations to safeguard workers.

Australia has already banned the use of artificial stone as of July 2024, aiming to eliminate the health risks associated with its production and installation.

In related editorials, Dr. Christopher Barber and researchers from Sheffield Teaching Hospitals NHS Foundation Trust drew parallels between artificial stone silicosis and historical occupational health crises, urging stricter regulations and enforcement to protect workers.

Experts are currently reviewing exposure limits for crystalline silica dust in the UK, with a focus on mitigating the risks associated with artificial stone worktops. Silicosis remains a significant concern for clinicians and researchers in the occupational health field.

About our experts

Patrick Howlett: An MRC Clinical Research Fellow at the National Heart and Lung Institute, Imperial College London, focusing on silicosis and tuberculosis among small-scale miners in Tanzania.

Christopher Barber: A leading expert in occupational and environmental lung disease, serving as a medical advisor to the UK Health and Safety Executive and conducting extensive research in the field.


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Source: www.sciencefocus.com