Best CBD Vape Juice & Oil: Top 3 Brands of 2021
By Annamarie Meli
CBD has taken the world by storm thanks to its keen therapeutic properties and potential medical benefits. CBD has been praised for many things: its therapeutic uses, potential medical benefits, and anti-anxiety and relaxation properties. As CBD becomes more popular and standard, you are perhaps wondering if you can benefit from CBD.
There is a lot of misinformation about CBD out there, from claims that it can cure any disease to claims that it is actually harmful. We care about factual information here so we put together this comprehensive guide on the best CBD vape juice and oils for consumer use. All of our reviews are backed by peer-reviewed science and we take the time to vet each company that we recommend thoroughly.
Today we are going to discuss CBD vape juices and oils. Without a doubt, one of the most popular ways to consume CBD, vaping or smoking has become the top choice for consumers. What makes these products so unique is that they provide a near instant-acting dose. This can be incredibly practical for those who do not want to fuss with drops, creams or edibles. So if you are interested in learning more about the wild and wonderful world of CBD vape juice and oil, then read on.
Top CBD Vape Juice & Oil: Summary
Our peer-reviewed, non-biased system involves concise and formulated testing. To skip ahead of our in-depth discussion here are our top favorite picks:
This transparent approach has provided our readers with a clear resource to make informed and educated buying decisions.
The Formula: How We Put It All Together
We take our CBD research seriously. That is why we thoroughly vet every product and brand that we recommend. Here is a list of factors we consider when choosing and ranking our brand selection.
Hemp source - Hemp source is one of the most important parts of the CBD manufacturing process. If you have poorly grown and poorly cultivated hemp, then you will have a bad product. To that end, we make sure to only pick companies that grow organic hemp according to the most up-to-date botanical and cultivation methods. We also make sure to choose companies that use organically grown, locally-sourced hemp.
Extraction process - Another important factor we consider is extraction process; i.e. how the product is made. There are 3 major types of extraction for CBD products. The first is the simplest and involves crushing the leaves and stems and removing the residual mixture. This process is simple and can be performed in your kitchen but is highly inefficient.
Solvent extraction involves running the hemp plant through a solvent mixture (most of the time it's ethanol) then boiling away the solvent to leave the oil residue. The last common method is called supercritical CO2 extraction. With this process, supercooled liquid CO2 acts as the solvent. The CO2 is then evaporated off leaving behind the pure oil residue. Supercritical CO2 extraction is considered the gold standard when it comes to CBD production. As such, we try to find companies that use supercritical methods for their products.
Manufacturing standards - CBD is neither regulated nor approved by the FDA for medical use. As such, there are no universal federal standards for the manufacture of CBD. That being said, there are several third-party organizations that vet companies based on manufacturing standards and the quality/accuracy of their products. These agencies test company products to make sure that they are made properly and actually contain what they are advertised to contain. As such, we only choose products and companies that have readily accessible third-party lab reports ascertaining the quality of ingredients and production. Any company that does not provide this information for consumers is automatically excluded from consideration.
Type of products - CBD is a diverse molecule and can be made into many products. Some companies may specialize in a specific type of CBD product while others may make many kinds. We always make sure that companies we pick have a suitable level of diversity among their product offerings.
Extra ingredients - CBD products rarely contain just CBD and nothing else. Many contain a full spectrum of cannabinoids and other molecules such as terpenes. We make sure that any companies we choose use all-natural ingredients and do not rely on any synthetic or artificial chemicals. We also look at the type and quality of alternative ingredients
Potency - Potency refers to the overall strength of the mixture. Potency is normally measured in milligrams per milliliter (mg/ml). Most of the time a product will list the potency on the label along with the quantity and volume of the product. Potency is very important because it determines the recommended dose that you should take. More potent CBD can produce stronger effects quicker.
Brand transparency - It is important when dealing with CBD companies that the brand is transparent about their products, methods, and supply chains. So, when looking for companies, we make sure only to pick those that have reliable and transparent business practices, product labelings, and company information/policies.
Website and buying experience - Another important factor we consider is the overall experience shopping and buying on the website. It is very frustrating when you have to deal with an arduous buying or shipping process. So we take website experience and the buying process seriously when considering recommendations.
Customer reviews and testimonials - The last major factor we consider is customer reviews and testimonials. Customer reviews encompass more than just the quality of products. They also talk about how it is to interact with the company and the overall company experience. Customer reviews can also give insights in specific matters that general product descriptions cannot give. They also give a good indication of the public reputation of a company.
CBD Vape Juice & Oil: Product Info
1. CBDfx - Best Variety & Top Choice
First up on our roundup is CBDfx, which has won our admiration for their high-quality products and diverse lineup. This San Francisco-based company was founded in 2014 and has quickly become one of the best and most well-known suppliers of CBD products. Founders Ali Esmalli and Jameson Rogers were inspired to create CBDfx with the goal of providing pure, high-quality products at an affordable price.
The most distinctive feature of CBDfx is their large product lineup. Browsing through their pages, you will find oils, tinctures, vape products, edibles, gummies, creams, salves, and more. Most product types include full spectrum, broad spectrum, and isolate variants. You can pretty much find any kind of CBD product you need from CBDfx. They also have special product lines designed for specific ailments such as their Sleep and Relaxation lines. They also offer CBD products and treats for pets.
All of CBD products are made using locally sourced, organically grown hemp from California and are made using a state-of the art supercritical CO2 extraction method. This extraction method ensures a high-degree of purity and potency. As far as vaping products go, CBDfx offers vape kits complete with cartridges and vaporizer elements, as well as refills. They also offer several different flavors including watermelon, strawberry kiwi, blue raspberry, and natural flavorings. Additionally, all products are 100% vegan and do not contain artificial preservatives or flavorings.
CBDfx has made waves in the CBD community and has generally very positive customer reviews. In particular, customers appreciate the high quality products and excellent customer service. CBDfx offers free shipping on all orders above $35 but also the option to upgrade to priority mail, first class, or FedEx shipping for a small fee. As far as returns go, CBDfx offers a 30 day money-back guarantee for unused and unopened products.
Overall, CBDfx is one of the best CBD companies out there right now. They offer an extremely wide range of products and are vetted by third-party lab tests.
- Large variety of products including tinctures, edibles, capsules, vaping kits and more
- 100% vegan products made with supercritical CO2 extraction methods
- Several flavor profiles including common and unconventional flavorings
- Excellent customer reviews and testimonials
- Free shipping on orders above $35 with options for upgraded shipping
Lab Results - All lab results for each product are included in a link on the product description page. CBDfx charters CCTL for all of their testing requirements. Their vaping product all test positive for quality and lack or impurities.
Shipping & Returns - CBDfx offers free shipping on orders above $35 to all 50 states in the US and also offers a 30-day money back guarantee for unused and unopened products. Customers must pay shipping for returns though.
- Divers array of products
- High quality production methods
- Generous shipping and return policies
- Locally source organic hemp
- 100% vegan products
- Slightly more expensive
- Free shipping takes 5-8 days
2. Diamond CBD - Best Value
Next up on our list is Diamond CBD. This Colorado-based CBD company is one of several owned by Potnetwork Holdings which owns several other cannabis companies nationwide.
Diamond CBD, like CBDfx, has a very large product selection, including tinctures, oils, Balms, vape products, edibles, and more. Their product listing for tinctures alone is over 4 pages long. Moreover, every product has an associated lab report so you can check each product's purity, potency, and quality.
Diamond CBD uses multiple extraction methods for their products, including solvent-based extraction, supercritical CO2 extraction, and olive oil extraction. The exact method they use for different products is different. However, the majority of products are made with supercritical CO2 extraction.
In addition to their large product lineup, Diamond CBD also has special lines for specific ailments. They have a Relax line of gummies and tinctures to promote health and combat insomnia, as well as products specifically for pain. They have products ranging in size from 500mg to 1500mg, which, while not as potent as other brands, still has good variety. All of Diamond CBD vape products are full spectrum and contain a wide blend of cannabinoids and other molecules such as terpenes.
As far as shipping goes, Diamond CBD offers free shipping on all purchases over $100. They offer a $10 flat shipping rate otherwise. One of the best aspects of Diamond CBD is how affordable their products are. Their products range between $0.05-$0.12 per mg of CBD which is on the more affordable side of the scale. They also offer a 30-day money back guarantee on all unopened and unused products.
With respect to vaping oils, CBD Diamond offers a wide selection. They offer both vape kits and vape juice refills. Their listing includes several flavorings, including strawberry, watermelon, honey, and natural flavorings.
- Huge range of products available
- Supercritical CO2 extraction method for the majority of its products
- Locally sourced hemp out of Colorado and Kentucky
- Small potency blends available for purchase
- Extremely generous return policies
Lab results - Diamond CBD has their lab reports furnished by Green Science Labs. Their lab reports can be found at the bottom of the main page in one of the links. Each product has an associated lab report and you can search based on product name.
Shipping & Returns - Diamond CBD offers free shipping to all 50 states for purchases over $100. Otherwise, they charge a flat $10 shipping rate. They have a 30-day return policy on all unused and unopened products.
- Wide selection of products
- Detailed lab reports for all products
- Very affordable prices
- Multiple speciality lines of products
- Large selection of flavors
- Website design could use some work
- Shipping rate of $10 is fairly high
3. Empe USA - Great Taste
Last on our roundup is Empe USA. This US-based CBD company offers 100% organic CBD products and includes a decent range of product types. Empe USA makes all of their products using locally sourced hemp and does not include any synthetic or artificial ingredients.
Empe offers a decent range of products, including oils, tinctures, gummies, creams, salves, and more. Their vape products are all isolate blends and contain no other molecules. Empe USA also features lab reports for all of their products. You can find lab reports at the bottom of the page and search for specific products listings.
Empe USA offers CBD vape juice concentrations of 350mg. Their products are on the more expensive side of the spectrum with $0.12 per mg of CBD. However, the company frequently offers discounts so you can usually get something for a lower price than what is listed.
The vast majority of reviewers claim that Empe USA's products helped them achieve relaxation and reduced pain. There were also several reviews claiming that their skin products helped manage conditions like dry and cracked skin.
AS far as their vaping products go, Empe USA offers a wide selection of vaping juice refills, entire vaping kits, and solo disposable cartridges. Most of their flavors are modeled after the taste of famous cannabis strains such as Blue Dream or Gorilla OG.
Empe offers free shipping on all orders over $100. Otherwise, they charge a flat $5.95 rate, which is fairly low, all things considered. They also offer a standard 30-day return policy for all unused and unopened items. Customers must handle shipping costs for returns though.
- Excellent quality products
- Wide selection of CBD products
- Good natural flavors
- Wide selection of vaping products
- Free shipping for orders over $100
Lab Results - All Empe US lab reports are furnished by Steep Hill labs. You can browse lab reports by clicking on the link at the bottom of the page.
Shipping & Returns - Empe US offers free shipping on all orders over $100 to all 50 states. They charge a flat $5.95 shipping rate for all orders under $100. They also offer a standard 30-day return policy which, while not amazing, is fairly standard for CBD companies.
- Good selection of products
- Large selection of vaping products
- Free shipping on orders over $100
- Great flavors modeled after traditional cannabis strains
- Lab reports for all products
- Website is slightly confusing to navigate
- Extraction method is not specified on official website
- Return policy is not amazing
Where Does CBD Come From?
CBD comes from the cannabis plant, however, there is a bit more nuance to it than just that. Cannabis can be divided into two main types of plants called marijuana and hemp. Marijuana typically refers to cannabis plants that contain more than 0.3% THC per mass while hemp refers to cannabis plants that have less than 0.3% THC by mass. Most CBD oils are made from hemp and so contain a very low if not negligible amount of THC.
CBD oil can also be divided into types based on the ingredients. Isolates are the most pure form and only contain CBD suspended in some matrix, normally vegetable glycerin or glycol. Broad spectrum blends include a larger variety of cannabinoids such as CBG, CBC, and CBN. Full spectrum blends contain a diverse cannabinoid profile including THC, as well as other molecules such as terpenes, vitamins, and fatty acids.
What Are CBD Vape Products?
CBD can be vaporized and inhaled. To that end, many companies offer CBD vaping products. These products normally involve a vape with disposable or refillable cartridges. The vape apparatus vaporizes the CBD contained in the cartridge, which is then inhaled. It is the same principle behind e-cigarettes and THC vape products.
CBD vape products can be found in isolate, broad spectrum, or full spectrum varieties. Each kind of variety is suited for a specific purpose. Most CBD vaping products are normally broad or full spectrum and usually contain THC, however some do not. Full spectrum vaping products also contain other molecules such as terpenes.
Vaporization is normally considered a potent way to ingest CBD and so it is not for everyone. Because the vapor is inhaled, the molecule enters the bloodstream much quicker, so vaping produces a fast and relatively intense feeling.
How Does CBD Work?
CBD has become an interesting object of study by scientists because of its potential therapeutic and medicinal properties. CBD has been shown to:
- Reduce anxiety
- Reduce inflammation
- Reduce nociceptive and neuropathic pain
- Manage neuropathy
- Has neuroprotective properties
- Anti-tumor benefits
Out of all these effects, the pain reducing and anti-inflammatory properties of CBD are the most well-established. CBD has been shown to have anti-inflammatory properties and has also been shown to be as effective as several traditional methods of pain management. There is also some evidence that CBD might have anti-tumor properties, although there is still no consensus on that matter. CBD has been noted as particularly effective in managing cancer and cancer-treatment related symptoms such as pain, loss of appetite, and anxiety.
To be clear, CBD is not medicine and is not generally approved by the FDA for medical use. CBD is not intended to serve as a substitute or replacement for any approved medical treatment and CBD is not known to cure any diseases.
In fact, there are only 2 FDA-approved medicines that contain CBD as their active ingredient, both of which are meant to treat certain forms of epilepsy. Since CBD is not approved for medical use, you should always talk to your doctor first before using a CBD product.
The exact mechanism of action of CBD is still a matter of scientific investigation, though there is a growing consensus that CBD works on the body's endocannabinoid system. The endocannabinoid is a large network of cannabinoid receptors throughout the body's brain and nervous tissue. Research has shown that the endocannabinoid system is involved in mediating several homeostatic processes in the body.
As such, there is a growing belief in the medical community that several seemingly disparate chronic conditions might be explained by an imbalance in the body's endocannabinoid system. Conditions such as fibromyalgia, IBS, and some auto-immune conditions might be related to the endocannabinoid system. CBD has become a target of interest to medical researchers in virtue of its effects on the system.
The endocannabinoid system contains two types of receptors, dubbed CB1 and CB2. CB1 receptors are located primarily in the brain while CB2 receptors are located primarily in the central and peripheral nervous system. CBD is a partial agonist of both receptors, so while it does interact with the receptors, it does not fully fit into the "lock-and-key" mechanism. The exact nature of CBD's interaction with CB1 and CB2 receptors is still a matter of investigation.
THC also interacts with the endocannabinoid receptors but in a different way. Thus CBD is not associated with the psychoactive effects of THC. You will not get "high" from CBD, although many report a sense of general relaxation and calm after taking CBD.
Dosage and Side Effects
CBD is not regulated or approved by the FDA so there are no accepted standards as to what the acceptable dosage of CBD is. Experiments involving CBD range from very small doses to fairly high doses, though few experiments focus specifically on finding the proper dosage per unit of dobby weight.
However, most experts recommend that you start with a dosage of 1 mg of CBD per 10 lbs. Of body weight. So for example, if you weigh 150 lbs, then a good recommended dose to start with would be 15mg. You should always start with a smaller does and slowly increase the dosage by 1-2mg per week until you achieve the desired effects. It is generally not recommended to exceed more than 100mg of CBD per day, although this depends on your specific situation.
CBD has been shown to be non-toxic, even in extremely high doses. The LD50 of CBD in humans has not been determined but animal studies show that it is likely extremely high and CBD does not produce lasting negative effects even at very high doses. As such, it is virtually impossible that you could overdose on CBD. It is also not associated with a "hangover" or withdrawal effects as it is non-addictive and non-habit forming.
CBD does have a handful of side effects, though most of them are mild and tend to go away once you get used to taking the product. The most common reported side effects of CBD are:
- Dry mouth
- Changes in appetite
- Upset stomach
The most commonly reported side effect is fatigue and tiredness. The other side effects tend to decrease as you body acclimates to taking the supplement. However, the specific side effects you experience may be heavily dependent on your individual bodily constitution. Some people just react differently to the molecule.
CBD has quickly become one of the most popular therapeutic methods for managing a diverse range of conditions. CBD used to be fairly expensive but increased customer demand and competition between businesses has resulted in a large amount of affordable CBD products for the average consumer. As CBD becomes more popular, we can expect even more company and a wider range of CBD products. This is good news for you as you will have more choices than ever.
Based on our round up, CBDfx is the top CBD provider. They offer a wide range of high-quality products with a solid range of concentrations/potencies. CBDfs also uses high-quality organic CBD for its products and uses a sophisticated supercritical CO2 extraction method. In that sense, CBDfx is one of the best CBD providers on the market right now and any enthusiast can find something to love from them.
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.
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.
"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.
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.
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.
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.