
The U.S. has quietly withdrawn 17 sites from the UNESCO World Network of Biosphere Reserves program.
As first reported by National Geographic, the sites include a number of national forests, preserves and reserves from Alaska to the Virgin Islands (see list below). There were previously 47 biosphere reserves in the U.S.
The move was made during the International Coordinating Council of the Man and the Biosphere Programme meeting in Paris this week. Bulgaria also removed three sites.
"Prior to this year, a total of 18 sites had been removed from the program since 1997, by seven countries," National Geographic noted.
"It's not currently clear why the U.S. and Bulgaria asked to remove those sites: requests for comment have not yet been returned. In the past, sites were removed after countries were no longer able to meet the requirements of the program for protecting them."
According to the United Nations, biosphere reserves are nominated by national governments and remain under the sovereign jurisdiction of the states where they are located.
As detailed by the conservation nonprofit George Wright Society, the biosphere program was launched in the 1970s to establish internationally designated protected areas, help minimize the loss of biological diversity, raise awareness on how cultural diversity and biological diversity affect each other, and promote environmental sustainability.
But over the years, the program has been criticized by certain individuals and groups as—per this Infowars post—a United Nations "land grab" of American landmarks.
The George Wright Society writes:
"A large, almost bewildering variety of charges have been alleged about biosphere reserves. Many of these charges revolve around a basic fear and distrust of the United Nations. This category of objections includes such claims as the United Nations is poised to invade the United States, confiscate American land, impose some kind of 'new world order'� on citizens here, and so forth. There is no truth whatsoever to these charges."
The U.S. removed the following sites from the biosphere reserve program:
- Aleutian Islands National Wildlife Refuge - US Fish & Wildlife Service
- Beaver Creek Experimental Watershed - US Forest Service
- California Coast Ranges - University of California Natural Reserve System
- Carolinian South-Atlantic - Non-Game and Heritage Trust (South Carolina)
- Central Plains Experimental Range - USDA Agricultural Research Service
- Coram Experimental Forest - US Forest Service
- Desert Experimental Range - US Forest Service
- Fraser Experimental Forest - US Forest Service
- H.J. Andrews Experimental Forest - US Forest Service / Oregon State University
- Hubbard Brook - US Forest Service
- Konza Prairie Research Natural Area - Kansas State University
- Land Between the Lakes - US Forest Service
- Niwot Ridge Mountain Research Station - University of Colorado
- Noatak National Preserve - National Park Service
- Stanislas-Tuolumne Experimental Forest - US Forest Service
- Three Sisters Wilderness - US Forest Service
- Virgin Islands - National Park Service
The good news is that 23 new sites around the world were added to the network at the council meeting this week. These are the new designations, as detailed by UNESCO's official press release:
Mono Biosphere Reserve (Benin)—Located in the southwest of the country, this 9,462 ha site comprises ecosystems that include mangroves, wetlands, savannah and forests. It is home to notable biodiversity flagship species such as the dugong, or sea cows, hippos and two monkey species. Nearly 180,000 inhabitants live within the reserve, mostly from livestock and small scale farming of palm oil and coconuts, as well as fishing.
Mono Transboundary Biosphere Reserve (Benin/Togo)—Located in the southern parts of Benin and Togo, the 346,285 ha. site stretches over the alluvial plain, delta and coast of the Mono River. It brings together Benin's and Togo's national biosphere reserves of the same name and features a mosaic of landscapes and ecosystems, mangroves, savannahs, lagoons, and flood plains as well as forests, some of which are sacred. The biosphere reserve is home to some two million people, whose main activity is small-scale farming (palm oil and coconuts), livestock grazing, forestry and fishing.
Savegre Biosphere Reserve (Costa Rica)—This site is located on the central Pacific coast, 190 km from the capital, San José. This reserve has high biodiversity value, hosting 20% of the total flora of the country, 54% of its mammals and 59% of its birds. It has approximately 50,000 inhabitants, whose main activities are agriculture and livestock rearing. Crop production is significant in high altitude areas, including plantations of apple, pomegranate and avocado. During recent years, ecotourism has increased and has become a source of socio-economic growth in the region.
Moen Biosphere Reserve (Denmark)—This reserve consists of a series of islands and islets in the southern Baltic Sea, over approximately 45,118 ha. Its landscapes include woodlands, grasslands, meadows, wetlands, coastal areas, ponds and steep hills. This biosphere reserve includes a number of small villages, scattered farms and residential areas with a total population of some 45,806 inhabitants. The main activities are trade, agriculture, fishing and tourism.
La Selle - Jaragua-Bahoruco-Enriquillo Transboundary Biosphere Reserve (Dominican Republic / Haiti)—This biosphere reserve includes the reserves of La Selle in Haiti, designated in 2012, and Jaragua-Bahoruco in the Dominican Republic, designated in 2002. These two reserves represent ecological corridors divided by a political and administrative frontier. Bringing them together should allow better management of the environment.
Bosques de Paz Transboundary Biosphere Reserve (Ecuador/Peru)—Located in the southwest of Ecuador and in northwest of Peru, this site covers a total area of 1,616,988 ha. It includes territories of the western foothills of the Andes, with altitudes reaching up to 3,000 metres, which have generated a biodiversity with a high degree of endemism. The biosphere reserve includes the seasonally dry forests of Ecuador and Peru, which form the heart of the Endemic Region of Tumbes, one of the most important biodiversity hotspots of the world. This region has 59 endemic species, of which 14 are threatened. Most of its 617,000 inhabitants make a living from livestock and tourism.
Majang Forest Biosphere Reserve (Ethiopia)—Located in the west of the country, this biosphere reserve includes Afromontane forests in one of the most fragmented and threatened regions in the world. The landscape also includes several wetlands and marshes. At altitudes above 1,000 metres, vegetation chiefly consists of ferns and bamboo, while palm trees cover the lower areas. The biodiversity rich region is home to 550 higher plant species, 33 species of mammal and 130 species of birds alongside a human population of about 52,000.
Black Forest Biosphere Reserve (Germany)—Located in the south of the country, this biosphere reserve contains low mountain ranges, forests shaped by silviculture, lowland and mountain hay meadows and lowland moors. The total surface area of the site is 63,325 ha, 70% of which is forested. 38,000 inhabitants live in the area, which has preserved its traditions and maintain a significant craft industry. Sustainable tourism is widely encouraged.
San Marcos de Colón Biosphere Reserve (Honduras) – This site, which covers a surface area of 57,810 ha, is located some 12 km from the Nicaraguan border, at an altitude of 500 to 1700 metres. It is characterized by significant biodiversity and the presence of several endemic species of fauna. Eighteen villages are located on the site whose population numbers 26,350 inhabitants. Their principal activities include horticulture, fruit and coffee production, the growth of ornamental plants, cattle rearing and dairy production. The region is also known for its saddlery products (belts, harnesses, boots etc).
Tepilora, Rio Posada and Montalbo Biosphere Reserve (Italy)—Located in Sardinia, this biosphere reserve has a total surface area of over 140,000 ha, and presents mountainous areas to the west and a flat strip to the east, rivers and coastal areas. Around 50,000 people live on this site, which includes the Montalbo massif.
Sobo, Katamuki and Okue Biosphere Reserve (Japan)—This site, which is part of the Sobo-Katamuki-Okue mountain range, is characterized by precipitous mountains. Forests cover 85% of the 243,672 ha of the site, which is a hotspot of biodiversity in the region. The area has fewer than 100,000 inhabitants, whose livelihood comes from farming and exploiting forest resources, including wood production, shitake mushroom cultivation, and charcoal production.
Minakami Biosphere Reserve (Japan)—The site includes the central divide of the rivers of the island of Honshu formed by a 2,000 metre high backbone. Significant environmental differences between the eastern and western slopes, between mountainous and lowland areas create a distinct biological and cultural diversity. More than 21,000 people live in the reserve, which covers a total of 91,368 ha. Their main activities are agriculture and tourism.
Altyn Emel Biosphere Reserve (Kazakhstan)—This biosphere reserve covers the same areas as the Altyn Emel state national nature park, one of the country's protected areas, which is very important for the conservation of the region's biological diversity. It includes a large number of endemic plants. The site comprises deserts, riparian forests and floodplains of the Ili River, deciduous and spruce forests as well as salt marshes. The resident population of about 4,000 lives mainly from agriculture and cattle rearing as well as ecotourism and recreational tourism.
Karatau Biosphere Reserve (Kazakhstan)—Located in the central part of the Karatau ridgeway, a branch of Northwestern Tien Shan, one of the world's largest mountain ranges, the reserve covers a total surface area of 151,800 ha and is inhabited by 83,000 people. It is an extremely important natural complex for the conservation of West Tien Shan biodiversity. Karatau occupies first place among Central Asian regions in terms of its wealth of endemic species. The region's economy rests primarily on cattle rearing, agriculture, ecotourism and recreational tourism.
Indawgyi Biosphere Reserve (Myanmar)—Indawgyi Lake is the largest body of freshwater in Myanmar. With a total surface area of 133,715 ha, the site consists of a large open lake with floating vegetation areas, a swamp forest and seasonally flooded grasslands. The hills surrounding the lake are covered by subtropical moist broadleaf forests that harbour a number of threatened forest birds and mammals, including primates. The local population derives most of its income from farmlands bordering the lake.
Gadabedji Biosphere Reserve (Niger)—Located in the centre of the country, the site extends over an area of 1,413,625 ha. It comprises a mosaic of savannahs, depressions, pits and sand dunes. Its fauna includes mammals such as dorcas gazelle, pale fox, and golden jackal. The human population of the reserve belongs to two main ethnic groups, Touaregs and Peulhs, totalling close to 20,000 inhabitants, whose main activity is nomadic pastoralism.
Itaipu Biosphere Reserve (Paraguay)—Located in the east of the country, the reserve covers a surface area of over a million hectares. It comprises an area of semi-deciduous sub-tropical forest also known as the Upper Paraná Atlantic Forest. It is one of the most important ecosystems for the conservation of biological diversity on a global scale, due to its large number of endemic species, wealth of species and original cover. It is home to large predators such as harpies, jaguars, pumas and large herbivores such as tapirs. It has a permanent population of over 450,000 inhabitants.
Castro Verde Biosphere Reserve (Portugal)—Located in southern Portugal, in the hinterland of the Baixo Alentejo region, the biosphere reserve covers an area of almost 57,000 ha. It encompasses the most important cereal steppe area in Portugal, one of the most threatened rural landscapes in the Mediterranean region. It has a high degree of endemism in its flora. There is a bird community of some 200 species, including steppe birds such as the great bustard and endemic species such as the Iberian Imperial eagle, one of the most endangered birds of prey in the world. Some 7,200 inhabitants make a living from the extensive production of cereals and livestock rearing in the reserve.
Khakassky Biosphere Reserve (Russian Federation)—Located at the heart of the Eurasian continent and known for its rich biodiversity, more than 80 % of this biosphere reserve is covered by mountain-taiga. With a surface area of almost 2 million hectares, it is home to 5,500 permanent inhabitants. Sustainable forest management and agriculture, beekeeping and tourism are the main economic activities practised in the site.
Kizlyar Bay Biosphere Reserve (Russian Federation)—Kizlyar Bay is one of the largest bays in the Caspian Sea and one of the largest migratory routes for birds in Eurasia. It represents a diversity of marine, coastal and desert-steppe ecosystems, including populations of threatened animals, such as the Caspian seal, many species of birds and sturgeons. With a surface area of 354,100 ha, it has a permanent population of 1,600 inhabitants who depend on fishing, land use (grazing and haymaking), hunting and tourism.
Metsola Biosphere Reserve (Russian Federation)—Located at the border with Finland, the site comprises the Kostomukshsky reserve and contains one of the oldest intact north-taiga forests in Northwest Russia. Some 30,000 permanent inhabitants live in this biosphere reserve, with a surface area of 345,700 ha. The north-taiga forests are essential for the reproduction of many bird species. The local population lives from forestry, agriculture, fishing, hunting and gathering non-timber forest products.
Great Altay Transboundary Biosphere Reserve (Russian Federation / Republic of Kazakhstan)—The reserve is composed of the Katunskiy biosphere reserve (Russian Federation, designated in 2000) and the Katon-Karagay biosphere reserve (Kazakhstan, designated in 2014). With a surface area of over 1.5 million ha, the area is used for livestock rearing, grazing, red deer farming, fodder production and apiculture. Tourism, hunting, fishing, and the collection of non-timber forest products are also widespread.
Backo Podunavlje Biosphere Reserve (Serbia)—Located in the northwestern part of Serbia, this site, with a surface area of 176,635 ha, extends over the alluvial zones of the central Danube plain. It is composed of remnants of historic floodplains and human-made landscapes influenced by agriculture and human settlements. The floodplain includes alluvial forests, marshes, reed beds, freshwater habitats, alluvial wetlands, as well as flood-protected forests. The main activities of the 147,400 inhabitants are agriculture, forestry and industry.
Garden Route Biosphere Reserve (South Africa)—With a total area of 698,363 ha and a population of over 450,000, this site is part of the Cape Floristic Region biodiversity hotspot region. The Knysna estuary is of great importance for the conservation of this biodiversity. The eastern part of the biosphere reserve is characterised by the presence of wetlands in which farming practices and urban development could have a negative impact. Faunal diversity includes large mammals such as elephants, rhino and buffalo.
Jebel Al Dair Biosphere Reserve (Sudan)—This reserve is constituted of the Al Dair massif, composed of dry savannah woodlands, forested ecosystems and a network of streams. It is one of the last remaining areas with rich biodiversity in the semi-arid North Kordofan. The site numbers 112 plant species, most with medicinal and aromatic uses. There are also 220 bird species and 22 mammal and reptile species.
Mono Biosphere Reserve (Togo)—The site covering an area of 203,789 ha in the southeast of the country encompasses several coastal ecosystems—mangroves, wetlands, forests and flood plains, as well as farmlands used for small-scale production of palm oil and coconuts. There is also fishing and livestock rearing. The presence of sacred forests and isolated sacred trees is testimony to the vitality of the traditional cultural practices of the biosphere reserve's 1,835,000 inhabitants.
On Thursday, April 22, the world will celebrate Earth Day, the largest non-religious holiday on the globe.
This Earth Day falls at a critical turning point. It is the second Earth Day since the start of the coronavirus pandemic and follows a year of devastating climate disasters, such as the wildfires that scorched California and the hurricanes that battered Central America. But the day's organizers still have hope, and they have chosen a theme to match.
"At the heart of Earth Day's 2021 theme, Restore Our Earth, is optimism, a critically needed sentiment in a world ravaged by both climate change and the pandemic," EarthDay.org president Kathleen Rogers told USA TODAY.
Last Earth Day marked the first time that the holiday was celebrated digitally to prevent the spread of COVID-19. This will largely be the case this year as well.
"Most of our Earth Day events will be virtual with the exception of individual and small group cleanups through our 'Great Global Cleanup' program," EarthDay.org's Olivia Altman told USA TODAY.
If you do want to participate in person, you can either host or join a cleanup here. Otherwise, EarthDay.org is streaming three days of climate action beginning tomorrow.
Tuesday, April 20: A Global Youth Summit begins at 2:30 p.m. ET featuring young climate activists like Greta Thunberg and Alexandria Villaseñor. This will be followed at 7 p.m. ET by "We Shall Breathe," a virtual summit organized by the Hip Hop Caucus to look at issues like the climate crisis, pollution and the pandemic through an environmental justice lens.
Wednesday, April 22: Beginning at 7 a.m. ET, Education International will lead the "Teach for the Planet: Global Education Summit." Talks will be offered in multiple languages and across multiple time zones to emphasize the importance of education in fighting the climate crisis.
Thursday, April 22: On the day itself, EarthDay.org will host its second ever Earth Day Live digital event beginning at 12 p.m. ET. This event will feature discussions, performances and workshops focusing on the day's theme of restoring our Earth through natural solutions, technological innovations and new ideas.
The digital event is also designed to parallel a global leaders summit on climate being hosted by the Biden administration.
"EARTHDAY.ORG looks forward to contributing to the success of this historic climate summit and making active progress to Restore Our Earth," Rogers said in a press release. "We must see every country rapidly raise their ambition across all climate issues — and that must include climate education which would lead to a green jobs-ready workforce, a green consumer movement, and an educated and civically engaged citizenry around the world."
EarthDay.org grew out of the first Earth Day in 1970, which drew 20 million U.S. residents to call for greater environmental protections. The movement has been credited with helping to establish the U.S. Environmental Protection Agency and to pass landmark environmental legislation like the Clean Air and Water Acts. It has since gone on to be a banner day for environmental action, such as the signing of the Paris agreement in 2016. More than one billion people in more than 192 countries celebrate Earth Day each year.
This legacy continues. The organization called the scheduling of Biden's summit a "clear acknowledgement of the power of Earth Day."
"This is a critical stepping stone for the U.S. to rejoin the world in combating the climate crisis. In concert with several planned parallel EARTHDAY.ORG events worldwide, Earth Day 2021 will accelerate global action on climate change," EarthDay.org wrote.
NASA is teaming up with an innovative non-profit to hunt for greenhouse gas super-emitters responsible for the climate crisis.
Super-emitters are individual sources such as leaking pipelines, landfills or dairy farms that produce a disproportionate amount of planet-warming emissions, especially methane and carbon dioxide. Carbon Mapper, the non-profit leading the effort, hopes to provide a more targeted guide to reducing emissions by launching special satellites that hunt for sources of climate pollution.
"What we've learned is that decision support systems that focus just at the level of nation states, or countries, are necessary but not sufficient. We really need to get down to the scale of individual facilities, and even individual pieces of equipment, if we're going to have an impact across civil society," Riley Duren, Carbon Mapper CEO and University of Arizona researcher, told BBC News. "Super-emitters are often intermittent but they are also disproportionately responsible for the total emissions. That suggests low-hanging fruit, because if you can identify and fix them you can get a big bang for your buck."
The new project, announced Thursday, is a partnership between multiple entities, including Carbon Mapper, the state of California, NASA's Jet Propulsion Laboratory (JPL) and Planet, a company that designs, builds and launches satellites, according to a press release. The project is being implemented in three stages.
The initial stage, which is already complete, involved the initial engineering development. NASA and Planet will work together in the second stage to build two satellites for a 2023 launch. The third phase will launch an entire constellation of satellites starting in 2025.
The satellites will include an imaging spectrometer built by NASA's JPL, NASA explained in a press release. This is a device that can break down visible light into hundreds of colors, providing a unique signature for chemicals such as methane and carbon dioxide. Most imaging spectrometers currently in orbit have larger pixel sizes, making it difficult to locate emission sources that are not always visible from the ground. However, Carbon Mapper spectrometers will have pixels of around 98 square feet, facilitating more detailed pin-pointing.
"This technology enables researchers to identify, study and quantify the strong gas emission sources," JPL Scientist Charles Miller said in the press release.
Once the data is collected, Carbon Mapper will make it available to industry and government actors via an open data portal to help repair leaks.
"These home-grown satellites are a game-changer," California Governor Gavin Newsom said of the project. "They provide California with a powerful, state-of-the-art tool to help us slash emissions of the super-pollutant methane — within our own borders and around the world. That's exactly the kind of dynamic, forward-thinking solution we need now to address the existential crisis of climate change."
By Jenna McGuire
Commonly used herbicides across the U.S. contain highly toxic undisclosed "inert" ingredients that are lethal to bumblebees, according to a new study published Friday in the Journal of Applied Ecology.
The study reviewed several herbicide products and found that most contained glyphosate, an ingredient best recognized from Roundup products and the most widely used herbicide in the U.S. and worldwide.
While the devastating impacts of glyphosate on bee populations are more broadly recognized, the toxicity levels of inert ingredients are less understood because they are not subjected to the same mandatory testing by the U.S. Environmental Protection Agency (EPA).
"Pesticides are manufactured and sold as formulations that contain a mixture of compounds, including one or more active ingredients and, potentially, many inert ingredients," explained the Center for Food Safety in a statement. "The inert ingredients are added to pesticides to aid in mixing and to enhance the products' ability to stick to plant leaves, among other purposes."
The study found that these inert substances can be highly toxic and even block bees' breathing capacity, essentially causing them to drown. While researchers found that some of the combinations of inert ingredients had no negative impacts on the bees, one of the herbicide formulations killed 96% of the bees within 24 hours.
According to the abstract of the study:
Bees exhibited 94% mortality with Roundup® Ready‐To‐Use® and 30% mortality with Roundup® ProActive®, over 24 hr. Weedol® did not cause significant mortality, demonstrating that the active ingredient, glyphosate, is not the cause of the mortality. The 96% mortality caused by Roundup® No Glyphosate supports this conclusion.
"This important new study exposes a fatal flaw in how pesticide products are regulated here in the U.S.," said Jess Tyler, a staff scientist at the Center for Biological Diversity. "Now the question is, will the Biden administration fix this problem, or will it allow the EPA to continue its past practice of ignoring the real-world harms of pesticides?"
According to the Center for Food Safety, there are currently 1,102 registered formulations that contain the active ingredient glyphosate, each with a proprietary mixture of inert ingredients. In 2017, the group filed a legal petition calling for the EPA to force companies to provide safety data on pesticide formulations that include inert ingredients.
"The EPA must begin requiring tests of every pesticide formulation for bee toxicity, divulge the identity of 'secret' formulation additives so scientists can study them, and prohibit application of Roundup herbicides to flowering plants when bees might be present and killed," said Bill Freese, science director at the Center for Food Safety. "Our legal petition gave the EPA a blueprint for acting on this issue of whole formulations. Now they need to take that blueprint and turn it into action, before it's too late for pollinators."
ATTN @EPA: Undisclosed "inert" ingredients in #pesticide products warrant further scrutiny! ➡️ A new study compared… https://t.co/bdFwXCVHsD— Center 4 Food Safety (@Center 4 Food Safety)1618592343.0
Roundup — also linked to cancer in humans — was originally produced by agrochemical giant Monsanto, which was acquired by the German pharmaceutical and biotech company Bayer in 2018.
The merger of the two companies was condemned by environmentalists and food safety groups who warned it would cultivate the greatest purveyor of genetically modified seeds and toxic pesticides in the world.
Reposted with permission from Common Dreams.
By Ayesha Tandon
New research shows that lake "stratification periods" – a seasonal separation of water into layers – will last longer in a warmer climate.
These longer periods of stratification could have "far-reaching implications" for lake ecosystems, the paper says, and can drive toxic algal blooms, fish die-offs and increased methane emissions.
The study, published in Nature Communications, finds that the average seasonal lake stratification period in the northern hemisphere could last almost two weeks longer by the end of the century, even under a low emission scenario. It finds that stratification could last over a month longer if emissions are extremely high.
If stratification periods continue to lengthen, "we can expect catastrophic changes to some lake ecosystems, which may have irreversible impacts on ecological communities," the lead author of the study tells Carbon Brief.
The study also finds that larger lakes will see more notable changes. For example, the North American Great Lakes, which house "irreplaceable biodiversity" and represent some of the world's largest freshwater ecosystems, are already experiencing "rapid changes" in their stratification periods, according to the study.
'Fatal Consequences'
As temperatures rise in the spring, many lakes begin the process of "stratification." Warm air heats the surface of the lake, heating the top layer of water, which separates out from the cooler layers of water beneath.
The stratified layers do not mix easily and the greater the temperature difference between the layers, the less mixing there is. Lakes generally stratify between spring and autumn, when hot weather maintains the temperature gradient between warm surface water and colder water deeper down.
Dr Richard Woolway from the European Space Agency is the lead author of the paper, which finds that climate change is driving stratification to begin earlier and end later. He tells Carbon Brief that the impacts of stratification are "widespread and extensive," and that longer periods of stratification could have "irreversible impacts" on ecosystems.
For example, Dr Dominic Vachon – a postdoctoral fellow from the Climate Impacts Research Centre at Umea University, who was not involved in the study – explains that stratification can create a "physical barrier" that makes it harder for dissolved gases and particles to move between the layers of water.
This can prevent the oxygen from the surface of the water from sinking deeper into the lake and can lead to "deoxygenation" in the depths of the water, where oxygen levels are lower and respiration becomes more difficult.
Oxygen depletion can have "fatal consequences for living organisms," according to Dr Bertram Boehrer, a researcher at the Helmholtz Centre for Environmental Research, who was not involved in the study.
Lead author Woolway tells Carbon Brief that the decrease in oxygen levels at deeper depths traps fish in the warmer surface waters:
"Fish often migrate to deeper waters during the summer to escape warmer conditions at the surface – for example during a lake heatwave. A decrease in oxygen at depth will mean that fish will have no thermal refuge, as they often can't survive when oxygen concentrations are too low."
This can be very harmful for lake life and can even increase "fish die-off events" the study notes.
However, the impacts of stratification are not limited to fish. The study notes that a shift to earlier stratification in spring can also encourage communities of phytoplankton – a type of algae – to grow sooner, and can put them out of sync with the species that rely on them for food. This is called a "trophic mismatch."
Prof Catherine O'Reilly, a professor of geography, geology and the environment at Illinois State University, who was not involved in the study, adds that longer stratified periods could also "increase the likelihood of harmful algae blooms."
The impact of climate change on lakes also extends beyond ecosystems. Low oxygen levels in lakes can enhance the production of methane, which is "produced in and emitted from lakes at globally significant rates," according to the study.
Woolway explains that higher levels of warming could therefore create a positive climate feedback in lakes, where rising temperatures mean larger planet-warming emissions:
"Low oxygen levels at depth also promotes methane production in lake sediments, which can then be released to the surface either via bubbles or by diffusion, resulting in a positive feedback to climate change."
Onset and Breakup
In the study, the authors determine historical changes in lake stratification periods using long-term observational data from some of the "best-monitored lakes in the world" and daily simulations from a collection of lake models.
They also run simulations of future changes in lake stratification period under three different emission scenarios, to determine how the process could change in the future. The study focuses on lakes in the northern hemisphere.
The figure below shows the average change in lake stratification days between 1900 and 2099, compared to the 1970-1999 average. The plot shows historical measurements (black), and the low emission RCP2.6 (blue), mid emissions RCP6.0 (yellow) and extremely high emissions RCP8.5 (red) scenarios.
Change in lake stratification duration compared to the 1970-1999 average, for historical measurements (black), the low emission RCP2.6 (blue) moderate emissions RCP6.0 (yellow) and extremely high emissions RCP8.5 (red). Credit: Woolway et al (2021).
The plot shows that the average lake stratification period has already lengthened. However, the study adds that some lakes are seeing more significant impacts than others.
For example, Blelham Tarn – the most well-monitored lake in the English Lake District – is now stratifying 24 days earlier and maintaining its stratification for an extra 18 days compared to its 1963-1972 averages, the study finds. Woolway tells Carbon Brief that as a result, the lake is already showing signs of oxygen depletion.
Climate change is increasing average stratification duration in lakes, the findings show, by moving the onset of stratification earlier and pushing the stratification "breakup" later. The table below shows projected changes in the onset, breakup and overall length of lake stratification under different emission scenarios, compared to a 1970-1999 baseline.
The table shows that even under the low emission scenario, the lake stratification period is expected to be 13 days longer by the end of the century. However, in the extremely high emissions scenario, it could be 33 days longer.
The table also shows that stratification onset has changed more significantly than stratification breakup. The reasons why are revealed by looking at the drivers of stratification more closely.
Warmer Weather and Weaker Winds
The timing of stratification onset and breakup in lakes is driven by two main factors – temperature and wind speed.
The impact of temperature on lake stratification is based on the fact that warm water is less dense than cool water, Woolway tells Carbon Brief:
"Warming of the water's surface by increasing air temperature causes the density of water to decrease and likewise results in distinct thermal layers within a lake to form – cooler, denser water settles to the bottom of the lake, while warmer, lighter water forms a layer on top."
This means that, as climate change causes temperatures to rise, lakes will begin to stratify earlier and remain stratified for longer. Lakes in higher altitudes are also likely to see greater changes in stratification, Woolway tells Carbon Brief, because "the prolonging of summer is very apparent in high latitude regions."
The figure below shows the expected increase in stratification duration from lakes in the northern hemisphere under the low (left), mid (center), and high (right) emission scenarios. Deeper colors indicate a larger increase in stratification period.
Expected increase in stratification duration in lakes in the northern hemisphere under the low (left), mid (centre) and high (right) emissions scenarios. Credit: Woolway et al (2021).
The figure shows that the expected impact of climate change on stratification duration becomes more pronounced at more northerly high latitudes.
The second factor is wind speed, Woolway explains:
"Wind speed also affects the timing of stratification onset and breakdown, with stronger winds acting to mix the water column, thus acting against the stratifying effect of increasing air temperature."
According to the study, wind speed is expected to decrease slightly as the planet warms. The authors note that the expected changes in near-surface wind speed are "relatively minor" compared to the likely temperature increase, but they add that it may still cause "substantial" changes in stratification.
The study finds that air temperature is the most important factor behind when a lake will begin to stratify. However, when looking at stratification breakup, it finds that wind speed is a more important driver.
Meanwhile, Vachon says that wind speeds also have implications for methane emissions from lakes. He notes that stratification prevents the methane produced on the bottom of the lake from rising and that, when the stratification period ends, methane is allowed to rise to the surface. However, according to Vachon, the speed of stratification breakup will affect how much methane is released into the atmosphere:
"My work has suggested that the amount of accumulated methane in bottom waters that will be finally emitted is related to how quickly the stratification break-up occurs. For example, a slow and progressive stratification break-up will most likely allow water oxygenation and allow the bacteria to oxidise methane into carbon dioxide. However, a stratification break-up that occurs rapidly – for example after storm events with high wind speed – will allow the accumulated methane to be emitted to the atmosphere more efficiently."
Finally, the study finds that large lakes take longer to stratify in spring and typically remain stratified for longer in the autumn – due to their higher volume of water. For example, the authors highlight the North American Great Lakes, which house "irreplaceable biodiversity" and represent some of the world's largest freshwater ecosystems.
These lakes have been stratifying 3.5 days earlier every decade since 1980, the authors find, and their stratification onset can vary by up to 48 days between some extreme years.
O'Reilly tells Carbon Brief that "it's clear that these changes will be moving lakes into uncharted territory" and adds that the paper "provides a framework for thinking about how much lakes will change under future climate scenarios."
Reposted with permission from Carbon Brief.
By Robert Glennon
Interstate water disputes are as American as apple pie. States often think a neighboring state is using more than its fair share from a river, lake or aquifer that crosses borders.
Currently the U.S. Supreme Court has on its docket a case between Texas, New Mexico and Colorado and another one between Mississippi and Tennessee. The court has already ruled this term on cases pitting Texas against New Mexico and Florida against Georgia.
Climate stresses are raising the stakes. Rising temperatures require farmers to use more water to grow the same amount of crops. Prolonged and severe droughts decrease available supplies. Wildfires are burning hotter and lasting longer. Fires bake the soil, reducing forests' ability to hold water, increasing evaporation from barren land and compromising water supplies.
As a longtime observer of interstate water negotiations, I see a basic problem: In some cases, more water rights exist on paper than as wet water – even before factoring in shortages caused by climate change and other stresses. In my view, states should put at least as much effort into reducing water use as they do into litigation, because there are no guaranteed winners in water lawsuits.
Alabama, pay attention to Supreme Court ruling against Florida in water war #Water #SDG6 https://t.co/wIjdoY6Ccr— Noah J. Sabich (@Noah J. Sabich)1617800452.0
Dry Times in the West
The situation is most urgent in California and the Southwest, which currently face "extreme or exceptional" drought conditions. California's reservoirs are half-empty at the end of the rainy season. The Sierra snowpack sits at 60% of normal. In March 2021, federal and state agencies that oversee California's Central Valley Project and State Water Project – regional water systems that each cover hundreds of miles – issued "remarkably bleak warnings" about cutbacks to farmers' water allocations.
The Colorado River Basin is mired in a drought that began in 2000. Experts disagree as to how long it could last. What's certain is that the "Law of the River" – the body of rules, regulations and laws governing the Colorado River – has allocated more water to the states than the river reliably provides.
The 1922 Colorado River Compact allocated 7.5 million acre-feet (one acre-foot is roughly 325,000 gallons) to California, Nevada and Arizona, and another 7.5 million acre-feet to Utah, Wyoming, Colorado and New Mexico. A treaty with Mexico secured that country 1.5 million acre-feet, for a total of 16.5 million acre-feet. However, estimates based on tree ring analysis have determined that the actual yearly flow of the river over the last 1,200 years is roughly 14.6 million acre-feet.
The inevitable train wreck has not yet happened, for two reasons. First, Lakes Mead and Powell – the two largest reservoirs on the Colorado – can hold a combined 56 million acre-feet, roughly four times the river's annual flow.
But diversions and increased evaporation due to drought are reducing water levels in the reservoirs. As of Dec. 16, 2020, both lakes were less than half full.
Second, the Upper Basin states – Utah, Wyoming, Colorado and New Mexico – have never used their full allotment. Now, however, they want to use more water. Wyoming has several new dams on the drawing board. So does Colorado, which is also planning a new diversion from the headwaters of the Colorado River to Denver and other cities on the Rocky Mountains' east slope.
Drought conditions in the continental U.S. on April 13, 2021. U.S. Drought Monitor, CC BY-ND
Utah Stakes a Claim
The most controversial proposal comes from one of the nation's fastest-growing areas: St. George, Utah, home to approximately 90,000 residents and lots of golf courses. St. George has very high water consumption rates and very low water prices. The city is proposing to augment its water supply with a 140-mile pipeline from Lake Powell, which would carry 86,000 acre-feet per year.
Truth be told, that's not a lot of water, and it would not exceed Utah's unused allocation from the Colorado River. But the six other Colorado River Basin states have protested as though St. George were asking for their firstborn child.
In a joint letter dated Sept. 8, 2020, the other states implored the Interior Department to refrain from issuing a final environmental review of the pipeline until all seven states could "reach consensus regarding legal and operational concerns." The letter explicitly threatened a high "probability of multi-year litigation."
Utah blinked. Having earlier insisted on an expedited pipeline review, the state asked federal officials on Sept. 24, 2020 to delay a decision. But Utah has not given up: In March 2021, Gov. Spencer Cox signed a bill creating a Colorado River Authority of Utah, armed with a $9 million legal defense fund, to protect Utah's share of Colorado River water. One observer predicted "huge, huge litigation."
How huge could it be? In 1930, Arizona sued California in an epic battle that did not end until 2006. Arizona prevailed by finally securing a fixed allocation from the water apportioned to California, Nevada and Arizona.
Litigation or Conservation
Before Utah takes the precipitous step of appealing to the Supreme Court under the court's original jurisdiction over disputes between states, it might explore other solutions. Water conservation and reuse make obvious sense in St. George, where per-person water consumption is among the nation's highest.
St. George could emulate its neighbor, Las Vegas, which has paid residents up to $3 per square foot to rip out lawns and replace them with native desert landscaping. In April 2021 Las Vegas went further, asking the Nevada Legislature to outlaw ornamental grass.
The Southern Nevada Water Authority estimates that the Las Vegas metropolitan area has eight square miles of "nonfunctional turf" – grass that no one ever walks on except the person who cuts it. Removing it would reduce the region's water consumption by 15%.
Water rights litigation is fraught with uncertainty. Just ask Florida, which thought it had a strong case that Georgia's water diversions from the Apalachicola-Chattahoochee-Flint River Basin were harming its oyster fishery downstream.
That case extended over 20 years before the U.S. Supreme Court ended the final chapter in April 2021. The court used a procedural rule that places the burden on plaintiffs to provide "clear and convincing evidence." Florida failed to convince the court, and walked away with nothing.
Robert Glennon is a Regents Professor and Morris K. Udall Professor of Law & Public Policy, University of Arizona.
Disclosure statement: Robert Glennon received funding from the National Science Foundation in the 1990s and 2000s.
Reposted with permission from The Conversation.