Climate Change News & Discussions

[wjfox]

[erowind]

[weatheriscool]

Weaker ocean cir­cu­la­tion led to more car­bon stor­age in the deep sea
https://phys.org/news/2021-12-weaker-oc ... orage.html
by MARUM

The movement of water masses in the ocean, its circulation, is an essential component of the global climate system. In a study recently published in the journal Proceedings of the National Academy of Science (PNAS), researchers were able to show that circulation in the deep ocean was significantly slowed down during the last glacial period. Analyses of sediment samples show that the decomposition of organic carbon in the water masses of the deep sea consumed the oxygen available there. Scientists from Oklahoma State University (U.S.), GEOMAR Helmholtz Centre for Ocean Research Kiel and MARUM—Center for Marine Environmental Sciences at the University of Bremen are involved in the publication.

As a natural sink for carbon, the ocean is a central element of the Earth's climate system. The amount of carbon removed from the system in the long run depends on how much particles containing carbon are stored in the seabed. Here, the availability of dissolved oxygen is of central importance, as it is consumed during the microbial decomposition of previously formed biomass. The distribution of oxygen in the water column is primarily determined by the vertical circulation. To answer the question of whether the corresponding conditions in the deep ocean were subject to changes in the recent history of the Earth, the authors of the new study examined sediment samples. Chemical elements that can be used as indicators for oxygen-free conditions and are preserved in the sediment over thousands to millions of years were analyzed.

[weatheriscool]

Study: Climate-only models likely underestimate species extinction
https://phys.org/news/2021-12-climate-o ... ction.html
by Mikayla MacE Kelley, University of Arizona

Ecologists estimate that 15 to 37 percent of plant and animal species will go extinct as a direct result of the rapidly changing climate. But new University of Arizona-led research published in the journal Ecology Letters shows that current models don't account for the complexities of ecosystems as they are impacted by climate change. As a result, these extinction rates are likely underestimated.

As the climate continues to rapidly change, the area in which a given species can live often shrinks. Researchers wondered what factors beyond climate must be considered when trying to determine species abundance, distribution and risk of extinction.

"This is a central question in ecology, and it has become even more important with climate change," said study co-author Margaret Evans, assistant professor of dendrochronology in the UArizona Laboratory of Tree Ring Research.

Evans and her collaborators used data from over 23,000 piñon pines in the southwestern United States to model how climate affects the pine species. While climate affects the trees directly via temperature and precipitation, it also impacts them indirectly through its influence on insects and fire, the researchers found. Those indirect effects can cause rapid shifts in the trees' population and distribution on the landscape. The researchers say this nuance cannot be captured using climate-only models, which base their estimates on direct climate impacts.

[wjfox]

[wjfox]

[raklian]

I wonder how much of this is attributed to the declining population of Japan.

[weatheriscool]

Himalayan glaciers melting at 'exceptional rate'
https://phys.org/news/2021-12-himalayan ... ional.html
by University of Leeds

The accelerating melting of the Himalayan glaciers threatens the water supply of millions of people in Asia, new research warns.

The study, led by the University of Leeds, concludes that over recent decades the Himalayan glaciers have lost ice ten times more quickly over the last few decades than on average since the last major glacier expansion 400-700 years ago, a period known as the Little Ice Age.

The study also reveals that Himalayan glaciers are shrinking far more rapidly than glaciers in other parts of the world—a rate of loss the researchers describe as "exceptional".

The paper, which is published in Scientific Reports, made a reconstruction of the size and ice surfaces of 14,798 Himalayan glaciers during the Little Ice Age. The researchers calculate that the glaciers have lost around 40 percent of their area—shrinking from a peak of 28,000 km2 to around 19,600 km2 today.

During that period they have also lost between 390 km3 and 586 km3 of ice—the equivalent of all the ice contained today in the central European Alps, the Caucasus, and Scandinavia combined. The water released through that melting has raised sea levels across the world by between 0.92 mm and 1.38 mm, the team calculates.

[wjfox]

[wjfox]

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[wjfox]

Great piece by Monbiot –

https://www.theguardian.com/commentisfr ... ampaigning

"As crucial Earth systems might be approaching their tipping point, governments still propose to address the issue with tiny increments of action, across decades. It’s as if, in 2008, when Lehman Brothers collapsed and the global financial system began to sway, governments had announced that they would bail out the banks at the rate of a few million pounds a day between then and 2050. The system would have collapsed 40 years before their programme was complete. Our central, civilisational question, I believe, is this: why do nations scramble to rescue the banks but not the planet?"

[wjfox]

[wjfox]

[wjfox]

Global methane concentration hits 1,900 ppb

6th January 2022

The National Oceanic and Atmospheric Administration (NOAA) has published its latest data for atmospheric methane. This shows that globally, methane is now at its highest level in recorded history and has just passed the 1,900 parts per billion (ppb) milestone.

Although carbon dioxide's contribution to climate change is greater overall, methane is far more potent on a per molecule basis. The global warming potential of methane has been estimated at 70 to 100 over a 20-year period. That is, over a 20-year period, it traps 70 to 100 times more heat per mass unit than CO2.

NOAA's newly published data – based on air samples taken at dozens of sites around the world – confirms that global atmospheric methane in September 2021 (the latest available month) reached 1,900.5 ppb, the highest level in human history and probably the highest in at least the last 800,000 years. For comparison, methane in pre-industrial times tended to stay below 700 ppb. The jump between 2020 and 2021, a difference of nearly 16 ppb, is also the highest annual increase on record.

Methane accounts for about 20% of the greenhouse gases produced by human activities.

https://www.futuretimeline.net/blog/202 ... 900ppb.htm

[caltrek]

Report Shows Greenland Ice Sheet Shrunk for 25th Straight Year in 2021
by Jessica Corbett
January 7, 2022

https://www.commondreams.org/news/2022/ ... port-shows

Introduction:

(Common Dreams) "2021 is the 25th year in a row in which Greenland's ice sheet lost more mass during the course of the melting season than it gained during the winter."

That's according to the latest report from Polar Portal, a website featuring observations from Danish research institutions that monitor the Greenland Ice Sheet and the sea ice in the Arctic.

The report explains that while "the early part of the summer was cold and wet with unusually heavy and late snowfall in June, which delayed the onset of the melting season," July saw a heatwave that "led to a considerable loss of ice."

The Greenland Ice Sheet lost about 166 billion tonnes of ice during the 12-month period that ended in August, which is near the annual average since the mid-1980s, the report notes. From September 1986 to August 2021, it has lost about 5,500 billion tonnes, contributing 1.5 centimeters to the average global rise in sea levels of about 12 centimeters.

The ice sheet ended this season with a net surface mass balance of about 396 billion tonnes. Although that "makes the current season the 28th lowest in the 41-year time series," or a "somewhat average year," the report highlights "how our perspective changes in line with climate change," explaining that in the late 1990s, "the same figure would have been regarded as a year with a very low surface mass balance in the climate picture at that time."

[caltrek]

Over 400 Weather Stations Set New Heat Records in 2021
by Brett Wilkins
January 7, 2022

https://www.commondreams.org/news/2022/ ... cords-2021

Introduction:

(Common Dreams) Last year saw record-breaking high temperatures recorded at more than 400 weather stations around the world, with meteorologists voicing alarm over what climate scientists say is the shape of things to come, according to a report published Friday.

The Guardian reports that 10 countries—Canada, Dominica, Italy, Morocco, Oman, Taiwan, Tunisia, Turkey, the United Arab Emirates, and the United States—set or matched their national monthly high temperature records last year.

"Climate change is real and it's now," tweeted Catherine McKenna, founder of Climate and Nature Solutions and a former Canadian environment and climate change minister.

McKenna noted the numerous Canadian temperature records that were shattered last year, including in Lytton, British Columbia, where the mercury soared to 49.6°C, or 121.3°F, in late June.

[weatheriscool]

Global methane concentrations above 1,900 ppb for first time
GHG
6 Jan 2022
Global methane concentrations have risen above the symbolic 1,900 nanomol/mol (ppb) threshold for the first time...
https://www.qcintel.com/article/global- ... -3535.html

[wjfox]

At this rate, I wouldn't be at all surprised if we hit 1.5°C within the next 2-3 years.

Probably during the next El Niño.

[caltrek]

Ocean Heat is at Record Levels, with Major Consequences
January 13, 2022

https://theconversation.com/ocean-heat- ... ces-174760

Extract:

(The Conversation) Q: Your latest research shows ocean heat is at record highs. What does that tell us about global warming?

A: (From climate scientist Kevin Trenberth) The world’s oceans are hotter than ever recorded, and their heat has increased each decade since the 1960s. This relentless increase is a primary indicator of human-induced climate change.

As oceans warm, their heat supercharges weather systems, creating more powerful storms and hurricanes, and more intense rainfall. That threatens human lives and livelihoods as well as marine life.

The oceans take up about 93% of the extra energy trapped by the increasing greenhouse gases from human activities, particularly burning fossil fuels. Because water holds more heat than land does and the volumes involved are immense, the upper oceans are a primary memory of global warming. I explain this in more detail in my new book “The Changing Flow of Energy Through the Climate System.”

Our study provided the first analysis of 2021’s ocean warming, and we were able to attribute the warming to human activities. Global warming is alive and well, unfortunately.