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Long-term ocean sampling in Narragansett Bay reveals plummeting plankton levels: Impact uncertain for local food web

May 29, 2024

Long-term ocean sampling in Narragansett Bay reveals plummeting plankton levels: Impact uncertain for local food web

University of Rhode Island (URI) researchers estimate that in Narragansett Bay, the level of tiny plantlike creatures called phytoplankton has dropped by half in the last half century, based on new analysis of a long-term time series study of the bay.

That’s what a new paper published by the University of Rhode Island’s Graduate School of Oceanography (GSO) reports—news, recently uncovered, that is both surprising and concerning.

Analyzing the full time series of the bay, the research team found that phytoplankton biomass in Narragansett Bay declined by a stunning 49% from 1968 to 2019. The intensity of the winter-spring bloom, which starts the annual cycle of productivity in the Bay, decreased over time and is also occurring earlier each year.

URI’s new study in PNAS (Proceedings of the National Academy of Sciences) shares information from one of the longest plankton time series in the world. The subject of study is not only a destination for generations of Rhode Islanders and tourists but a fruitful site of research for oceanographers at URI’s Narragansett Bay Campus.

“A lot of people live, work and play on the shores of Narragansett Bay,” Oceanography Professor Tatiana Rynearson says, providing key goods and services for the nearly 2 million people who inhabit its watershed.

…click on the above link to read the rest of the article…

Abrupt permafrost thaw found to intensify warming effects on soil CO₂ emission

May 8, 2024

Abrupt permafrost thaw found to intensify warming effects on soil CO₂ emission

Abrupt permafrost thaw intensifies warming effects on soil CO2 emission — Thermokarst landscape on the Tibetan Plateau. Credit: Wang Guanqin

According to a recent study published in Nature Geoscience, scientists have found that soil carbon dioxide (CO₂) emissions are more sensitive to climate warming in permafrost-collapsed areas than in non-collapsed areas.

This study, based on field warming experiments combined with laboratory incubation of soils from a large-scale sampling, provides new insights about permafrost carbon–climate feedback in the context of future climate warming.

Warmer temperatures have led to rapid permafrost thawing in high-latitude and high-altitude permafrost regions. Abrupt permafrost thaw, known as thermokarst, occurs in approximately 20% of the northern permafrost region, but this region stores about half of all below-ground organic carbon. This type of thawing can restructure land surface morphology, causing abrupt changes to the soil biotic and abiotic properties, which may significantly alter ecosystem carbon cycling.

Since both thermokarst and non-thermokarst areas are simultaneously experiencing ongoing warming, an important but so far overlooked consideration is whether the warming effects on soil CO₂ flux might differ between these two distinct landforms.

To fill this knowledge gap, a collaborative research group led by Prof. Yang Yuanhe from the Institute of Botany of the Chinese Academy of Sciences has investigated how thermokarst formation influences the responses of soil CO₂ fluxes to climate warming, using multiple approaches.

In a well-replicated warming experiment conducted simultaneously in thermokarst and non-thermokarst areas, the researchers found that the warming-induced increase in soil CO₂ release was about 5.5 times higher in thermokarst features than in adjacent non-thermokarst landforms.

They then analyzed over 30 potential drivers of the warming effects on CO₂ release using soil physicochemical analyses, solid-state ¹³C nuclear magnetic resonance, and metagenomic sequencing…

…click on the above link to read the rest of the article…

Coastal hurricanes around the world are intensifying faster, new study finds

May 5, 2024

Coastal hurricanes around the world are intensifying faster, new study finds

New study finds coastal hurricanes around the world are intensifying faster — With landfalling hurricanes comes strong winds and boosted precipitation, two factors that can exacerbate the impacts of storm surge and coastal flooding. In new work, PNNL scientists find that amplified warming in the upper troposphere and changes in heating patterns are driving hurricanes to intensify faster, specifically close to coastlines. Credit: CC0, Pixabay.com

Hurricanes are among the world’s most destructive natural hazards. Their ability to cause damage is shaped by their environment; conditions like warm ocean waters, guiding winds, and atmospheric moisture can all dictate storm strength.

A new study led by scientists at the Department of Energy’s Pacific Northwest National Laboratory finds that coastal conditions have changed since 1979, driving nearshore hurricanes around the world to intensify at a quickening pace. What’s more, new projections suggest this rate will continue climbing should current warming trends continue. The paper is published in the journal Earth’s Future.

Much work has been done to document how hurricanes are changing in our warmer world. Past research has shown these storms may grow wetter, threatening heightened risks of flooding. Other work suggests they may strike more often in some areas and that their intensity may peak closer to the coast, posing additional risk to the roughly 40 percent of the world’s population that lives within 100 kilometers (62.13 miles) of a coastline, according to the United Nations.

Yet, until now, no one has documented whether coastal hurricanes are intensifying faster at a global scale. Looking at past data, the authors of the new work found that the average rate at which these storms intensified over the period from 1979 to 2000 was 0.37 knots every six hours. That pace picked up for the period from 2000 to 2020, where the mean intensification rate was 1.15 knots every six hours.

…click on the above link to read the rest of the article…

Climate change supercharged a heat dome, intensifying 2021 fire season, study finds

April 28, 2024

Climate change supercharged a heat dome, intensifying 2021 fire season, study finds

As a massive heat dome lingered over the Pacific Northwest three years ago, swaths of North America simmered—and then burned. Wildfires charred more than 18.5 million acres across the continent, with the most land burned in Canada and California.

A new study has revealed the extent to which human-caused climate change intensified the extraordinary event, with researchers theorizing the heat dome was 34% larger and lasted nearly 60% longer than it would have in the absence of global warming. The heat dome, in turn, was associated with up to a third of the area burned in North America that year, according to the study, published in Communications Earth & Environment.

“What happens is you get a stagnated weather pattern—it’s very hot and very dry,” said study author Piyush Jain, research scientist with Natural Resources Canada. “And it dries out all the vegetation and makes whatever is on the ground extremely flammable.”

The study adds to a body of literature documenting how the fingerprints of climate change can be detected in events such as heat waves, droughts and wildfires.

Jain was living in Edmonton in late June 2021 when the mercury in North America’s northernmost million-resident city topped 100 degrees. “I was blown away,” he said. “I’d never experienced those temperatures anywhere I’d lived.”

Farther south, the town of Lytton, British Columbia, on June 29 experienced Canada’s hottest recorded temperature, 119 degrees, and was largely destroyed by a wildfire the next day..

…click on the above link to read the rest of the article…

Don’t blame Dubai’s freak rain on cloud seeding—the storm was far too big to be human-made

April 28, 2024

Don’t blame Dubai’s freak rain on cloud seeding—the storm was far too big to be human-made

lightning — Credit: Pixabay/CC0 Public Domain

Some years ago, I found myself making my way up the narrow stairs of a Learjet on a sultry runway in a deserted airport near the South Africa-Mozambique border. The humidity was there to taste—the air thick with it.

The weather radar was showing a fast-developing thundercloud. Our mission was to fly through the most active part of the storm, measure it, fly through again while dumping a bin load of dry ice, turn hard and fly through for a final measurement.

The inside of the Learjet resembled a food blender, so severe was the turbulence. Thousands of meters below, a smaller plane would be threading through the storm downdrafts measuring the rain. It isn’t something you do every day although the saucer-sized hail dents on the wings of the Learjet told of its many prior engagements.

Apart from the fun of flying through the core of a thunderstorm in a Learjet, I didn’t think much about the time I was lucky enough to be part of that project. Until I heard about the recent freak storm in Dubai.

The project I was part of, neatly named Rain (Rain Augmentation in Nelspruit), was a cloud seeding experiment several years in the making. Cloud seeding involves adding tiny particles into a cloud in order to give moisture something to attach to and form droplets. Gradually those droplets merge and become heavy enough to fall as rain. In theory, the “seeded” clouds will grow more droplets suitable for rain.

…click on the above link to read the rest of the article…

‘So hot you can’t breathe’: Extreme heat hits the Philippines

April 25, 2024

‘So hot you can’t breathe’: Extreme heat hits the Philippines

The heat index was expected to reach the 'danger' level of 42 degrees Celsius or higher in at least 30 cities and municipalities of the Philippines — The heat index was expected to reach the ‘danger’ level of 42 degrees Celsius or higher in at least 30 cities and municipalities of the Philippines.

Extreme heat scorched the Philippines on Wednesday, forcing thousands of schools to suspend in-person classes and prompting warnings for people to limit the amount of time spent outdoors.

The months of March, April and May are typically the hottest and driest in the archipelago nation, but conditions this year have been exacerbated by the El Niño weather phenomenon.

“It’s so hot you can’t breathe,” said Erlin Tumaron, 60, who works at a seaside resort in Cavite province, south of Manila, where the heat index reached 47 degrees Celsius (117 degrees Fahrenheit) on Tuesday.

“It’s surprising our pools are still empty. You would expect people to come and take a swim, but it seems they’re reluctant to leave their homes because of the heat.”

The heat index was expected to reach the “danger” level of 42C or higher in at least 30 cities and municipalities on Wednesday, the state weather forecaster said.

The heat index measures what a temperature feels like, taking into account humidity.

The Department of Education, which oversees more than 47,600 schools, said nearly 6,700 schools suspended in-person classes on Wednesday.

There was a 50 percent chance of the heat intensifying in the coming days, said Ana Solis, chief climatologist at the state weather forecaster.

“We need to limit the time we spend outdoors, drink plenty of water, bring umbrellas and hats when going outdoors,” Solis told AFP.

Solis said El Niño was the reason for the “extreme heat” affecting swaths of the country.

Around half the country’s provinces are officially in drought.

‘It’s really hot here’

…click on the above link to read the rest of the article…

Understanding climate warming impacts on carbon release from the tundra

April 23, 2024

Understanding climate warming impacts on carbon release from the tundra

The warming climate shifts the dynamics of tundra environments and makes them release trapped carbon, according to a new study published in Nature. These changes could transform tundras from carbon sinks into carbon sources, exacerbating the effects of climate change.

A team of more than 70 scientists from different countries used so-called open-top chambers (OTCs) to experimentally simulate the effects of warming on 28 tundra sites around the world. OTCs basically serve as mini-greenhouses, blocking wind and trapping heat to create local warming.

The warming experiments led to a 1.4 degrees Celsius increase in air temperature and a 0.4 degrees increase in soil temperature, along with a 1.6 percent drop in soil moisture. These changes boosted ecosystem respiration by 30 percent during the growing season, causing more carbon to be released because of increased metabolic activity in soil and plants. The changes persisted for at least 25 years after the start of the experimental warming—which earlier studies hadn’t revealed.

“We knew from earlier studies that we were likely to find an increase in respiration with warming, but we found a remarkable increase—nearly four times greater than previously estimated, though it varied with time and location,” says Sybryn Maes of Umeå University, the study’s lead author.

The increase in ecosystem respiration also varied with local soil conditions, such as nitrogen and pH levels. This means that differences in soil conditions and other factors lead to geographic differences in the response—some regions will see more carbon release than others. Understanding the links between soil conditions and respiration in response to warming is important for creating better climate models.

…click on the above link to read the rest of the article…

Hidden threat: Global underground infrastructure vulnerable to sea-level rise

April 21, 2024

Hidden threat: Global underground infrastructure vulnerable to sea-level rise

As sea levels rise, coastal groundwater is lifted closer to the ground surface while also becoming saltier and more corrosive. A recent study by Earth scientists at the University of Hawai’i (UH) at Mānoa has compiled research from experts worldwide showing that in cities where there are complex networks of buried and partially buried infrastructure, interaction with this shallower and saltier groundwater exacerbates corrosion and failure of critical systems such as sewer lines, roadways, and building foundations.

The research is published in the journal Annual Review of Marine Science.

“While it has been recognized that shallowing groundwater will eventually result in chronic flooding as it surfaces, what’s less known is that it can start causing problems decades beforehand as groundwater interacts with buried infrastructure,” said Shellie Habel, lead author and coastal geologist in the School of Ocean and Earth Science and Technology (SOEST) at UH Mānoa. “This knowledge gap often results in coastal groundwater changes being fully overlooked in infrastructure planning.”

The research team aimed to create awareness about these issues and offer guidance from world experts on managing them. Habel and co-authors reviewed existing literature to examine the diverse effects on different types of infrastructure. Additionally, by employing worldwide elevation data and geospatial data that indicate the extent of urban development, they identified 1,546 low-lying coastal cities and towns globally, where around 1.42 billion people live, that are likely experiencing these impacts.

…click on the above link to read the rest of the article…

Study identifies atmospheric and economic drivers of global air pollution

April 11, 2024

Study identifies atmospheric and economic drivers of global air pollution

Carbon monoxide emissions from industrial production have serious consequences for human health and are a strong indicator of overall air pollution levels. Many countries aim to reduce their emissions, but they cannot control air flows originating in other regions. A new study from the University of Illinois Urbana-Champaign looks at global flows of air pollution and how they relate to economic activity in the global supply chain.

“Our study is unique in combining atmospheric transport of air pollution with supply chain analysis as it tells us where the pollution is coming from and who is ultimately responsible for it,” said lead author Sandy Dall’erba, professor in the Department of Agricultural and Consumer Economics (ACE) and director of the Center for Climate, Regional, Environmental and Trade Economics (CREATE), both part of the College of Agricultural, Consumer and Environmental Sciences (ACES) at Illinois.

“There is a direct link between a country’s level of production and how much air pollution is emitted. However, production may be driven by demand from consumers in other countries. We use supply chain analysis to quantify the links between production and consumption. This helps us to understand how production in one country is linked to domestic and foreign demand,” he added.

The researchers traced the movement of pollutants through the atmosphere to understand the flow of emissions, using simulations developed by Nicole Riemer, professor in the Department of Climate, Meteorology & Atmospheric Sciences, College of Liberal Arts & Sciences at Illinois; for analytical purposes, they divided the world into five sections: the United States, Europe, China, South Korea, and the rest of the world. South Korea is located downwind of China, and it serves as an example of how a small country can be affected by pollution from a much larger upwind neighbor.

…click on the above link to read the rest of the article…

Advances and challenges in understanding compound weather and climate extremes

March 16, 2024

Advances and challenges in understanding compound weather and climate extremes

storm — Credit: Pixabay/CC0 Public Domain

In the context of global warming, many extremes, such as heat waves, heavy precipitation, and droughts, have become increasingly frequent and intense, as expected theoretically. Somewhat unexpectedly, these extremes have also exhibited tightened linkage in both time and space, constituting compound weather and climate extremes with larger impacts.

During the past decade, compound events received considerable attention, with much progress in event typology, impacts, changes and risks already made.

A study led by Prof. Zengchao Hao (College of Water Sciences, Beijing Normal University) and Prof. Yang Chen (State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences) explores more than a dozen recent compound events. The paper is published in the journal Science China Earth Sciences.

By synthesizing nearly 350 peer-reviewed papers, the authors thoroughly documented definitions and impacts, physical mechanisms, and historical/future changes as well as attribution evidence with respect to 13 reported and relatively well-studied compound events. Some of these events are specific to East Asian monsoonal regions.

They also pointed out deficiencies and gaps in existing studies on each of these events. At the end of the review, they attempted to identify data and methodological challenges common to the field and came up with outlooks on the future directions of the emerging topic.

More specifically, they laid out their review by order of definition, mechanisms, changes, and attribution. For each of the reviewed events, the authors adopted an impact-centric approach to introduce the definition by illustrating how the fashion of compounding aggregated and amplified impacts. Distinct from previous reviews on some types of compound events focusing largely on long-term changes, the new review assigned a large volume of space to the underlying physical processes, especially from the dynamic (including monsoon dynamics) and multi-sphere interactive perspectives.

…click on the above link to read the rest of the article…

Polar plastic: 97% of sampled Antarctic seabirds found to have ingested microplastics

March 16, 2024

Polar plastic: 97% of sampled Antarctic seabirds found to have ingested microplastics

Anthropogenic plastic pollution is often experienced through evocative images of marine animals caught in floating debris, yet its reach is far more expansive. The polar regions of the Arctic and Antarctica are increasingly experiencing the impacts of plastic reaching floating ice and land, not solely as larger macroplastics (>5 cm), but as microplastics (0.1 µm—5 mm) and nanoplastics (<0.1 µm) that may be carried vast distances from their source or be ingested in more populated areas during seasonal migration.

A new review, published in Frontiers in Marine Science, has investigated the scale of this issue, particularly with respect to seabirds who call these glaciated regions home.

Ph.D. researcher Davide Taurozzi and Professor Massimiliano Scalici, of Roma Tre University, Italy, embarked on a project to summarize 40 years of research into seabird ingestion of microplastics, from 1983 to the present day.

Across >1,100 samples, the researchers explored stomach contents, crop pouch near the throat for temporary food storage during foraging trips, guano (excrement mixture of food and metabolic waste) and regurgitated pellets of undigested food and other particles. Pellets formed the main component of the samples, followed by stomach contents and guano, while pouch contents were minimally present.

…click on the above link to read the rest of the article…

Ecological doom-loops: Why ecosystem collapses may occur much sooner than expected

August 27, 2023

Ecological doom-loops: Why ecosystem collapses may occur much sooner than expected

Around the world, rainforests are becoming savanna or farmland, savanna is drying out and turning into desert, and icy tundra is thawing. Indeed, scientific studies have now recorded “regime shifts” like these in more than 20 different types of ecosystem where tipping points have been passed. Around the world, more than 20% of ecosystems are in danger of shifting or collapsing into something different.

These collapses might happen sooner than you’d think. Humans are already putting ecosystems under pressure in many different ways—what we refer to as stresses. And when you combine these stresses with an increase in climate-driven extreme weather, the date these tipping points are crossed could be brought forward by as much as 80%.

This means an ecosystem collapse that we might previously have expected to avoid until late this century could happen as soon as in the next few decades. That’s the gloomy conclusion of our latest research, published in Nature Sustainability.

Human population growth, increased economic demands, and greenhouse gas concentrations put pressures on ecosystems and landscapes to supply food and maintain key services such as clean water. The number of extreme climate events is also increasing and will only get worse.

What really worries us is that climate extremes could hit already stressed ecosystems, which in turn transfer new or heightened stresses to some other ecosystem, and so on. This means one collapsing ecosystem could have a knock-on effect on neighboring ecosystems through successive feedback loops: an “ecological doom-loop” scenario, with catastrophic consequences.

How long until a collapse?

In our new research, we wanted to get a sense of the amount of stress that ecosystems can take before collapsing. We did this using models—computer programs that simulate how an ecosystem will work in future, and how it will react to changes in circumstance.

…click on the above link to read the rest…

Scientists warn of widespread drought in the 21st century

February 1, 2022

Scientists warn of widespread drought in the 21st century

Scientists sound alarm over widespread drought in the 21st century — Frequency changes (%) of different drought metrics from 1970–99 to 2070–99 under the (left) SSP2-4.5 and (right) SSP5-8.5 scenarios projected by CMIP6 multimodel ensemble mean. Credit: IAP

Drought is among the most damaging natural hazards in the world, often causing severe losses to agriculture, ecosystems and human societies.

Historical records of precipitation, streamflow and observation-derived drought indices all show increased aridity since 1950s over several hotspot regions, including Africa, southern Europe, East Asia, eastern Australia, Northwest Canada, and southern Brazil.

“Climate model projections also suggest that drought may become more severe and widespread as the greenhouse gas-induced global warming continues in the 21st century,” said Prof. Zhao Tianbao from the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences.

Recently, Zhao and Prof. Dai Aiguo from University at Albany, State University of New York, further investigated hydroclimatic and drought changes in the latest projections from 25 models of the Phase Six of the Coupled Model Inetercomparison Project (CMIP6).

Their results were published in the Journal of Climate on Jan. 5.

The study suggests that the latest projections from CMIP6 models reaffirm the widespread drying and increases in agricultural drought by up to 200 percent over most of the Americas (including the Amazon), Europe and the Mediterranean region, southern Africa, Southeast Asia, and Australia under moderate-high emissions scenarios in the 21st century.

As if that wasn’t bad enough, the drought is also expected to last longer and spread wider in the late 21st century (2070–99), Zhao noted.

The model results suggest a decrease in the mean and flattening of the probability distribution functions of drought metrics, despite large uncertainties in individual projections partly due to internal variability.

…click on the above link to read the rest of the article…

Early humans gained energy budget by increasing rate of energy acquisition, not energy-saving adaptation

December 31, 2021

Early humans gained energy budget by increasing rate of energy acquisition, not energy-saving adaptation

A team of researchers affiliated with multiple institutions in the U.S., the Institute for Advanced Study in Toulouse, France and the Max Planck Institute for Evolutionary Anthropology in Germany has found evidence that suggests early humans gained an energy budget by increasing their rate of energy acquisition, not by taking advantage of adaptive strategies. In their paper published in the journal Science, they describe their study of energy expenditure versus energy intake in early humans.

In this new effort, the researchers noted that humans long ago diverged in significant ways from the other great apes. They wondered how this happened and decided to look at energy intake and expenditure. People and other animals have to put in a certain amount of work (expenditure) to receive an energy intake. Climbing a tree to fetch a banana is a simple example. The amount of energy required to climb a tree far outweighs the potential benefit of eating a single banana. But if a single person is able to throw down multiple bananas, then the overall energy intake may surpass the effort of climbing a tree a single time…

…click on the above link to read the rest of the article…

If all 2030 climate targets are met, the planet will heat by 2.7 C this century

November 8, 2021

If all 2030 climate targets are met, the planet will heat by 2.7 C this century

If all 2030 climate targets are met, the planet will heat by 2.7℃ this century — Corals will not likely survive more than 2℃ global warming. Credit: Shutterstock

If nations make good on their latest promises to reduce emissions by 2030, the planet will warm by at least 2.7℃ this century, a report by the United Nations Environment Programme (UNEP) has found. This overshoots the crucial internationally agreed temperature rise of 1.5℃.

Released today, just days before the international climate change summit in Glasgow begins, UNEP’s Emissions Gap Report works out the difference between where greenhouse emissions are projected to be in 2030 and where they should be to avoid the worst climate change impacts.

It comes as the Morrison government yesterday officially committed to a target of net-zero emissions by 2050. The government made no changes to its paltry 2030 target to reduce emissions by between 26% and 28% below 2005 levels, but announced that Australia is set to beat this, and reduce emissions by up to 35%.

The UNEP report was conducted before Australia’s new 2050 target was announced, but even with this new pledge, global pledges will undoubtedly still be short of what’s needed.

The report found global targets for net-zero emissions by mid-century could cut another 0.5℃ off global warming. While this is a big improvement, it will still see temperatures rise to 2.2℃ this century. If we don’t close the global emissions gap, what will Australia, and the rest of world, be forced to endure?

Pledges are falling short

As of August 30 (the date the UNEP report reviewed to), 120 countries had made new or updated pledges and announcements to cut emissions.

The US, for example, has set an ambitious new target of reducing emissions by 50–52% below 2005 levels in 2030. Similarly, the European Union will cut carbon emissions by at least 55% by 2030, compared with 1990 levels.

…click on the above link to read the rest of the article…

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