Link between fast-melting Arctic ice and ocean acidification

An international team of researchers have sounded new alarm bells about the changing chemistry of the western region of the Arctic Ocean after discovering acidity levels increasing three to four times faster than ocean waters elsewhere.

The team, which includes University of Delaware marine chemistry expert Wei-Jun Cai, also identified a strong correlation between the accelerated rate of melting ice in the region and the rate of ocean acidification, a perilous combination that threatens the survival of plants, shellfish, coral reefs and other marine life and biological processes throughout the planet’s ecosystem.

The new study, published on Thursday, Sept. 30 in Science, the flagship journal of the American Association for the Advancement of Science, is the first analysis of Arctic acidification that includes data from more than two decades, spanning the period from 1994 to 2020.

— source University of Delaware | Sep 29, 2022

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Rural Alaska Has a Bridge Problem as Permafrost Thaws

America’s bridges are in rough shape. Of the nearly 620,000 bridges over roads, rivers and other waterways across the U.S., more than 43,500 of them, about 7%, are considered “structurally deficient.”

In Alaska, bridges face a unique and growing set of problems as the planet warms.

Permafrost, the frozen ground beneath large parts of the state, is thawing with the changing climate, and that’s shifting the soil and everything on it. Bridges are also increasingly crucial for rural residents who can no longer trust the stability of the rivers’ ice in spring and fall.

The infrastructure bill making its way through Congress currently includes US$40 billion in new federal funds for bridgeconstruction, maintenance and repairs – the largest investment in bridges since construction of the interstate highway system started in the 1950s. In that funding is about $225 million to address 140 structurally deficient

— source | Guangqing Chi, Davin Holen, Heather Randell, Megan Mucioki, Rebecca Napolitano | Oct 13, 2021

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Rising greenhouse gases pose continued threat to Arctic ozone layer

A new study from an international team of scientists, shows that extremely low winter temperatures high in the atmosphere over the arctic are becoming more frequent and more extreme because of climate patterns associated with global warming. The study also shows that those extreme low temperatures are causing reactions among chemicals humans pumped into the air decades ago, leading to greater ozone losses. The new findings call into question the commonly held assumption that ozone loss would grind to a halt in just a few decades following the 2010 global ban on the production of ozone depleting chemicals called chlorofluorocarbons (CFCs) and halons.

Most of the chlorine and a significant amount of the bromine in the stratosphere comes from the breakdown of CFCs, halons and other ozone-depleting substances. Normally within the Arctic polar vortex the chlorine is non-reactive, but clouds provide the right conditions for the chlorine to change form and react with bromine and sunlight to destroy ozone.

Despite drastic reduction of the industrial production of CFCs and halons since the Montreal Protocol in 1987 and the global ban that followed in 2010, these long-lasting compounds are still abundant in the atmosphere. According to the World Meteorological Organization, atmospheric chlorine and bromine produced by humans is not expected to fall below 50% of their highest levels until the end of this century.

— source University of Maryland | Jun 23, 2021

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Water limitations in the tropics offset carbon uptake from Arctic greening

More plants and longer growing seasons in the northern latitudes have converted parts of Alaska, Canada and Siberia to deeper shades of green. Some studies translate this Arctic greening to a greater global carbon uptake. But new research shows that as Earth’s climate is changing, increased carbon absorption by plants in the Arctic is being offset by a corresponding decline in the tropics.

Plant productivity in the frigid Arctic landscape is limited by the lengthy periods of cold. As temperatures warm, the plants in these regions have been able to grow more densely and extend their growing season, leading to an overall increase in photosynthetic activity, and subsequently greater carbon absorption in the region over the 35-year time span.

However, buildup of atmospheric carbon concentrations has had several other rippling effects. Notably, as carbon has increased, global temperatures have risen,[]– and the atmosphere in the tropics (where plant productivity is limited by the availability of water) has become drier. Recent increases in drought and tree mortality in the Amazon rainforest are one example of this, and productivity and carbon absorption over land near the equator have gone down over the same time period as Arctic greening has occurred, canceling out any net effect on global productivity.

— source | Dec 18, 2020

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A “new normal” is settling over the Arctic

Temperatures are rising, ice is melting, snow is disappearing and the region’s delicate ecosystems are rapidly evolving. It’s already not the same place it was a few decades ago, and it won’t be the same place a few more decades into the future.

That’s the stark conclusion of this year’s Arctic Report Card, an annual update on the Arctic climate from NOAA. The report was released yesterday with a virtual press conference hosted at the annual fall meeting of the American Geophysical Union.

“The report card provides a snapshot in time of a region in the middle of transition,” said Rick Thoman, a scientist at the University of Alaska, Fairbanks, and one of the report’s editors, speaking at the press conference. “Nearly everything in the Arctic, from ice and snow to human activity, is changing so quickly that there’s really no reason to think that in 30 years much of anything will be as it is today.”

Temperatures in the Arctic are currently rising at least twice as fast as the global average. In 2020, the Arctic experienced its second-warmest year on record (Greenwire, Dec. 8).

— source | Chelsea Harvey | Dec 9, 2020

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Deep Frozen Arctic Microbes Are Waking Up

In August 2019, Iceland held a funeral for the Okjökull Glacier, the first Icelandic glacier lost to climate change. The community commemorated the event with a plaque in recognition of this irreversible change and the grave impacts it represents. Globally, glacier melt rates have nearly doubled in the last five years, with an average loss of 832 mmw.e. (millimeters water equivalent) in 2015, increasing to 1,243 mmw.e. in 2020 (WGMS). This high rate of loss decreases glacial stores of freshwater and changes the structure of the surrounding ecosystem.

In the last 10 years, warming in the Arctic has outpaced projections so rapidly that scientists are now suggesting that the poles are warming four times faster than the rest of the globe. This has led to glacier melt and permafrost thaw levels that weren’t forecast to happen until 2050 or later. In Siberia and northern Canada, this abrupt thaw has created sunken landforms, known as thermokarst, where the oldest and deepest permafrost is exposed to the warm air for the first time in hundreds or even thousands of years.

As the global climate continues to warm, many questions remain about the periglacial environment. Among them: as water infiltration increases, will permafrost thaw more rapidly? And, if so, what long-frozen organisms might “wake up”?

Permafrost covers 24 percent of the Earth’s land surface, and the soil constituents vary with local

— source | Kimberley R. Miner, Arwyn Edwards, Charles Miller | Nov 20, 2020

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Arctic wildfires are emitting 35% more carbon compared to 2019

According to a recent report by the EU’s Copernicus Atmosphere Monitoring Service, carbon emissions in the Arctic have surpassed last year’s emissions by 35%. The latest data shows that about 245 megatonnes of CO2 have been released in 2020 so far. This is a far higher figure than the entirety of last year, when 181 megatonnes of CO2 were released as a result of wildfires. The data further shows that the peak month for wildfires in 2020 was July, with over 600 wildfires reported in late July as compared to 400 wildfires in the same time frame last year. More devastating is the fact that similar periods from 2003 through 2018 experienced an average of 100 wildfires.

— source | Sep 2, 2020

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Last Intact Ice Shelf in Canada Collapses Due to Global Warming

The last intact ice shelf in the Canadian Arctic collapsed and lost a large part of his area due to extremely high temperatures, according to the Canadian Ice Service (CIS), as reported on Friday. Canadian Arctic’s temperature for the current summer is 5C higher than las three decades average. The Milne Ice Shelf lost about 80 square kilometers in July. In 2020, polar ice reduction peaked for the last 40 years. The glaciers retreat and melting initiated in 1850, concurring with the industrialization of productive activities and greenhouse gas emission started.

— source | 7 Aug 2020

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Arctic Ocean acidification worse than previously expected

The ocean takes up large amounts of human-made CO2 from the atmosphere. This additional CO2 causes ocean acidification, a process that can already be observed today. Ocean acidification particularly impacts organisms that form calcium carbonate skeletons and shells, such as molluscs, sea urchins, starfish and corals. The Arctic Ocean is where acidification is expected to be greatest. ocean acidification in the Arctic Ocean is likely to be even worse than previously thought. The results show that the smallest of the seven seas will take up 20% more CO2 over the 21st century than previously expected, under the assumption that the atmospheric CO2 concentrations continue to increase. Ocean acidification negatively impacts organisms that build calcium carbonate skeletons and shells. In sufficiently acidic waters, these shells become unstable and begin to dissolve. A loss of these organisms is likely to impact the entire Arctic food chain up to fish and marine mammals

— source University of Bern | Jun 17, 2020

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