By Ryan Raman
Food intolerances and sensitivities are extremely common. In fact, it's estimated that between 2–20 percent of people worldwide may suffer from a food intolerance (1).
Elimination diets are the gold standard for identifying food intolerances, sensitivities and allergies through diet.
They remove certain foods known to cause uncomfortable symptoms and reintroduce them at a later time while testing for symptoms.
Allergists and registered dietitians have been using elimination diets for decades to help people rule out foods that are not tolerated well.
What Is an Elimination Diet?
An elimination diet involves removing foods from your diet that you suspect your body can't tolerate well. The foods are later reintroduced, one at a time, while you look for symptoms that show a reaction.
In that way, an elimination diet may alleviate symptoms like bloating, gas, diarrhea, constipation and nausea.
Once you have successfully identified a food your body can't tolerate well, you can remove it from your diet to prevent any uncomfortable symptoms in the future.
There are many types of elimination diets, which all involve eating or removing certain types of foods.
However, if you have a known or suspected food allergy, then you should only try an elimination diet under the supervision of a medical professional. Reintroducing a food allergen may trigger a dangerous condition called anaphylaxis (4, 5).
If you suspect you have a food allergy, check with your doctor before starting an elimination diet. Symptoms of an allergy include rashes, hives, swelling and difficulty breathing (6).
Summary: An elimination diet is a short-term diet that helps identify foods your body can't tolerate well and removes them from your diet.
How Does It Work?
An elimination diet is divided into two phases: elimination and reintroduction.
The Elimination Phase
The elimination phase involves removing foods you suspect trigger your symptoms for a short period of time, typically 2–3 weeks.
Eliminate foods that you think your body can't tolerate, as well as foods that are notorious for causing uncomfortable symptoms.
Some of these foods include nuts, corn, soy, dairy, citrus fruits, nightshade vegetables, wheat, foods containing gluten, pork, eggs and seafood (7).
During this phase, you can determine if your symptoms are due to foods or something else. If your symptoms still remain after removing the foods for 2–3 weeks, it is best to notify your doctor.
The Reintroduction Phase
The next phase is the reintroduction phase, in which you slowly bring eliminated foods back into your diet.
Each food group should be introduced individually, over 2–3 days, while looking for symptoms. Some symptoms to watch for include:
- Rashes and skin changes
- Joint pain
- Headaches or migraines
- Difficulty sleeping
- Changes in breathing
- Stomach pain or cramps
- Changes in bowel habits
If you experience no symptoms during the period where you reintroduce a food group, you can assume that it is fine to eat and move on to the next food group.
However, if you experience negative symptoms like those mentioned above, then you have successfully identified a trigger food and should remove it from your diet.
The entire process, including elimination, takes roughly 5–6 weeks.
If you plan to eliminate many food groups, seek advice from your doctor or a dietitian. Eliminating too many food groups may cause a nutritional deficiency.
Summary: An elimination diet works by removing foods you think cause discomfort. It then reintroduces them individually to check for symptoms.
What Can't You Eat on an Elimination Diet?
The best elimination diets are the most restricting.
The more foods you remove during the elimination phase, the more likely it is that you will discover which foods trigger uncomfortable symptoms.
Foods that are commonly removed during the elimination phase include:
- Citrus fruits: Avoid citrus fruits, such as oranges and grapefruits.
- Nightshade vegetables: Avoid nightshades, including tomatoes, peppers, eggplant, white potatoes, cayenne pepper and paprika.
- Nuts and seeds: Eliminate all nuts and seeds.
- Legumes: Eliminate all legumes, such as beans, lentils, peas and soy-based products.
- Starchy foods: Avoid wheat, barley, corn, spelt, rye, oats and bread. Also avoid any other gluten-containing foods.
- Meat and fish: Avoid processed meats, cold cuts, beef, chicken, pork, eggs and shellfish.
- Dairy products: Eliminate all dairy, including milk, cheese, yogurt and ice cream.
- Fats: Avoid butter, margarine, hydrogenated oils, mayonnaise and spreads.
- Beverages: Avoid alcohol, coffee, black tea, soda and other sources of caffeine.
- Spices and condiments: Avoid sauces, relish and mustard.
- Sugar and sweets: Avoid sugar (white and brown), honey, maple syrup, corn syrup and high-fructose corn syrup, agave nectar, desserts and chocolate.
If you suspect that other foods not on this list make you feel uncomfortable, it is highly recommended to remove them as well.
Summary: A good elimination diet is very restricting, which helps you identify as many trigger foods as possible.
What Can You Eat on an Elimination Diet?
Although an elimination diet is very restricting, there is still enough variety to make healthy and delicious meals.
Some foods you can eat include:
- Fruits: Most fruits, excluding citrus fruits.
- Vegetables: Most vegetables, excluding nightshades.
- Grains: Including rice and buckwheat.
- Meat and fish: Including turkey, lamb, wild game and cold-water fish like salmon.
- Dairy substitutes: Including coconut milk and unsweetened rice milk.
- Fats: Including cold-pressed olive oil, flaxseed oil and coconut oil.
- Beverages: Water and herbal teas.
- Spices, condiments and others: Including black pepper, fresh herbs and spices (excluding cayenne pepper and paprika) and apple cider vinegar.
To stay motivated during this restrictive phase, try designing new recipes and experimenting with herbs and spices to add delicious flavor to your dishes.
Summary: Although elimination diets are restricting, there are still plenty of food options to make healthy and delicious meals.
Other Types of Elimination Diets
Besides the traditional elimination diet described above, there are several other types of elimination diets.
Here are a few different types of elimination diets:
- Low-FODMAPs diet: Removes FODMAPs, which are short-chain carbohydrates that some people can't digest.
- Few foods elimination diet: Involves eating a combination of foods that you don't eat regularly. One example is the lamb and pears diet, which is popular in the US, where lamb and pears are not commonly eaten.
- Rare foods elimination diet: Similar to a few foods diet, but you can only eat foods that you rarely ever eat, as they are less likely to trigger your symptoms. Common foods on a rare food diet include yams, buckwheat and starfruit.
- Fasting elimination diet: Involves strictly drinking water for up to five days, then reintroducing food groups. This type of diet should only be done with permission from your doctor, as it can be dangerous to your health.
- Other elimination diets: These include lactose-free, sugar-free, gluten-free and wheat-free diets, among others.
Summary: There are many different types of elimination diets, including the low-FODMAPs diet, the few foods diet, the rare foods diet, fasting and more.
Benefits of an Elimination Diet
Elimination diets help you discover which foods cause uncomfortable symptoms so you can remove them from your diet.
However, an elimination diet has many other benefits, including:
1. It May Reduce Symptoms of Irritable Bowel Syndrome
Irritable bowel syndrome (IBS) is a very common gut disorder that affects between 10–15 percent of people worldwide (8).
Many people find that an elimination diet improves IBS symptoms like bloating, stomach cramps and gas.
In one study, 150 people with IBS followed either an elimination diet that excluded trigger foods or a fake elimination diet that excluded the same number of foods but not ones linked with uncomfortable symptoms.
People who followed the actual elimination diet reduced their symptoms by 10 percent and those who best stuck to the diet reduced symptoms by up to 26 percent (9).
2. It May Help People With Eosinophilic Esophagitis
Eosinophilic esophagitis (EE) is a chronic condition where allergies trigger inflammation of the esophagus, the tube that delivers food from mouth to stomach.
People with EE have difficulty swallowing foods that are dry and dense, increasing their risk of choking.
In one study of 146 patients with EE, more than 75 percent of all patients experienced significantly fewer symptoms and less inflammation through an elimination diet (12).
3. It May Reduce Symptoms of ADHD
ADHD (attention-deficit/hyperactivity disorder) is a behavioral disorder that affects 3–5 percent of all children and adults.
One analysis looked at 20 studies that restricted certain foods to improve ADHD symptoms. Researchers found that elimination diets helped reduce ADHD symptoms among children who were sensitive to foods (15).
However, children should not follow an elimination diet unless supervised by a medical professional.
Elimination diets restrict many essential nutrients that are important for growing children, and long-term restriction could stunt their growth.
4. It May Improve Skin Conditions Like Eczema
Eczema is a group of skin conditions that appear as red, itchy, cracked and inflamed skin.
There are many different causes of eczema, but many people find that eating certain foods can worsen their symptoms.
In one study of 15 participants with eczema, 14 found that an elimination diet reduced their symptoms and helped identify their trigger foods (18).
5. It May Reduce Chronic Migraines
Roughly 2–3 million people in the US alone suffer from chronic migraines (19).
The causes of migraines are still unclear, but studies have shown that inflammation could be a trigger (20).
In one study, 28 women and two men with frequent migraines followed an elimination diet for six weeks, which helped reduce the number of headache attacks during that time from nine to six (22).
Summary: An elimination diet may benefit people with IBS, ADHD, migraines, eosinophilic esophagitis and skin conditions like eczema.
Risks of an Elimination Diet
Although elimination diets are a great way to discover which foods cause you problems, they also come with a few risks.
For starters, elimination diets should only be followed for a short period of time, or between four and eight weeks.
Following an elimination diet for longer is not recommended, as it could cause nutrient deficiencies as a result of eliminating certain food groups.
Additionally, children and people with known or suspected allergies should only do an elimination diet under the supervision of a doctor.
Because elimination diets are restricting, taking away certain food groups for even a short period of time could stunt a child's growth (23).
Children are also more prone to severe reactions, like anaphylaxis, when reintroducing a food group. This is because their bodies can become extra sensitive to foods after avoiding them (24).
Summary: Elimination diets can reduce the intake of important nutrients if followed for too long. Children and people with known or suspected allergies should not follow an elimination diet unless supervised by their doctor.
The Bottom Line
Elimination diets can help you determine which foods your body can't tolerate well.
If you're experiencing symptoms that you think may be related to your diet, then an elimination diet could help you discover which foods are causing them.
However, elimination diets are not for everyone. Children should not try an elimination diet unless supervised by a doctor or dietitian.
Likewise, people with known or suspected allergies should only try an elimination diet the under the supervision of a doctor.
Finally, it's important to note that elimination diets should only be done short-term, as long-term restrictions may cause nutritional deficiencies.
Reposted with permission from our media associate Authority Nutrition.
EcoWatch Daily Newsletter
By Sherry H-Y. Chou, Aarti Sarwal and Neha S. Dangayach
The patient in the case report (let's call him Tom) was 54 and in good health. For two days in May, he felt unwell and was too weak to get out of bed. When his family finally brought him to the hospital, doctors found that he had a fever and signs of a severe infection, or sepsis. He tested positive for SARS-CoV-2, the virus that causes COVID-19 infection. In addition to symptoms of COVID-19, he was also too weak to move his legs.
When a neurologist examined him, Tom was diagnosed with Guillain-Barre Syndrome, an autoimmune disease that causes abnormal sensation and weakness due to delays in sending signals through the nerves. Usually reversible, in severe cases it can cause prolonged paralysis involving breathing muscles, require ventilator support and sometimes leave permanent neurological deficits. Early recognition by expert neurologists is key to proper treatment.
We are neurologists specializing in intensive care and leading studies related to neurological complications from COVID-19. Given the occurrence of Guillain-Barre Syndrome in prior pandemics with other corona viruses like SARS and MERS, we are investigating a possible link between Guillain-Barre Syndrome and COVID-19 and tracking published reports to see if there is any link between Guillain-Barre Syndrome and COVID-19.
Some patients may not seek timely medical care for neurological symptoms like prolonged headache, vision loss and new muscle weakness due to fear of getting exposed to virus in the emergency setting. People need to know that medical facilities have taken full precautions to protect patients. Seeking timely medical evaluation for neurological symptoms can help treat many of these diseases.
What Is Guillain-Barre Syndrome?
Guillain-Barre syndrome occurs when the body's own immune system attacks and injures the nerves outside of the spinal cord or brain – the peripheral nervous system. Most commonly, the injury involves the protective sheath, or myelin, that wraps nerves and is essential to nerve function.
Without the myelin sheath, signals that go through a nerve are slowed or lost, which causes the nerve to malfunction.
To diagnose Guillain-Barre Syndrome, neurologists perform a detailed neurological exam. Due to the nerve injury, patients often may have loss of reflexes on examination. Doctors often need to perform a lumbar puncture, otherwise known as spinal tap, to sample spinal fluid and look for signs of inflammation and abnormal antibodies.
Studies have shown that giving patients an infusion of antibodies derived from donated blood or plasma exchange – a process that cleans patients' blood of harmful antibodies - can speed up recovery. A very small subset of patients may need these therapies long-term.
The majority of Guillain-Barre Syndrome patients improve within a few weeks and eventually can make a full recovery. However, some patients with Guillain-Barre Syndrome have lingering symptoms including weakness and abnormal sensations in arms and/or legs; rarely patients may be bedridden or disabled long-term.
Guillain-Barre Syndrome and Pandemics
As the COVID-19 pandemic sweeps across the globe, many neurologic specialists have been on the lookout for potentially serious nervous system complications such as Guillain-Barre Syndrome.
Though Guillain-Barre Syndrome is rare, it is well known to emerge following bacterial infections, such as Campylobacter jejuni, a common cause of food poisoning, and a multitude of viral infections including the flu virus, Zika virus and other coronaviruses.
Studies showed an increase in Guillain-Barre Syndrome cases following the 2009 H1N1 flu pandemic, suggesting a possible connection. The presumed cause for this link is that the body's own immune response to fight the infection turns on itself and attacks the peripheral nerves. This is called an "autoimmune" condition. When a pandemic affects as many people as our current COVID-19 crisis, even a rare complication can become a significant public health problem. That is especially true for one that causes neurological dysfunction where the recovery takes a long time and may be incomplete.
Though there is clear clinical suspicion that COVID-19 can lead to Guillain-Barre Syndrome, many important questions remain. What are the chances that someone gets Guillain-Barre Syndrome during or following a COVID-19 infection? Does Guillain-Barre Syndrome happen more often in those who have been infected with COVID-19 compared to other types of infections, such as the flu?
The only way to get answers is through a prospective study where doctors perform systematic surveillance and collect data on a large group of patients. There are ongoing large research consortia hard at work to figure out answers to these questions.
Understanding the Association Between COVID-19 and Guillain-Barre Syndrome
While large research studies are underway, overall it appears that Guillain-Barre Syndrome is a rare but serious phenomenon possibly linked to COVID-19. Given that more than 10.7 million cases have been reported for COVID-19, there have been 10 reported cases of COVID-19 patients with Guillain-Barre Syndrome so far – only two reported cases in the U.S., five in Italy, two cases in Iran and one from Wuhan, China.
It is certainly possible that there are other cases that have not been reported. The Global Consortium Study of Neurological Dysfunctions in COVID-19 is actively underway to find out how often neurological problems like Guillain-Barre Syndrome is seen in hospitalized COVID-19 patients. Also, just because Guillain-Barre Syndrome occurs in a patient diagnosed with COVID-19, that does not imply that it was caused by the virus; this still may be a coincident occurrence. More research is needed to understand how the two events are related.
Due to the pandemic and infection-containment considerations, diagnostic tests, such as a nerve conduction study that used to be routine for patients with suspected Guillain-Barre Syndrome, are more difficult to do. In both U.S. cases, the initial diagnosis and treatment were all based on clinical examination by a neurological experts rather than any tests. Both patients survived but with significant residual weakness at the time these case reports came out, but that is not uncommon for Guillain-Barre Syndrome patients. The road to recovery may sometimes be long, but many patients can make a full recovery with time.
Though the reported cases of Guillain-Barre Syndrome so far all have severe symptoms, this is not uncommon in a pandemic situation where the less sick patients may stay home and not present for medical care for fear of being exposed to the virus. This, plus the limited COVID-19 testing capability across the U.S., may skew our current detection of Guillain-Barre Syndrome cases toward the sicker patients who have to go to a hospital. In general, the majority of Guillain-Barre Syndrome patients do recover, given enough time. We do not yet know whether this is true for COVID-19-related cases at this stage of the pandemic. We and colleagues around the world are working around the clock to find answers to these critical questions.
Sherry H-Y. Chou is an Associate Professor of Critical Care Medicine, Neurology, and Neurosurgery, University of Pittsburgh.
Aarti Sarwal is an Associate Professor, Neurology, Wake Forest University.
Neha S. Dangayach is an Assistant Professor of Neurology and Neurosurgery, Icahn School of Medicine at Mount Sinai.
Disclosure statement: Sherry H-Y. Chou receives funding from The University of Pittsburgh Clinical Translational Science Institute (CTSI), the National Institute of Health, and the University of Pittsburgh School of Medicine Dean's Faculty Advancement Award. Sherry H-Y. Chou is a member of Board of Directors for the Neurocritical Care Society. Neha S. Dangayach receives funding from the Bee Foundation, the Friedman Brain Institute, the Neurocritical Care Society, InCHIP-UConn Center for mHealth and Social Media Seed Grant. She is faculty for emcrit.org and for AiSinai. Aarti Sarwal does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
Reposted with permission from The Conversation.
One of the initial reasons social distancing guidelines were put in place was to allow the healthcare system to adapt to a surge in patients since there was a critical shortage of beds, ventilators and personal protective equipment. In fact, masks that were designed for single-use were reused for an entire week in some hospitals.
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By Jake Johnson
Unity Task Forces formed by presumptive Democratic presidential nominee Joe Biden and Sen. Bernie Sanders unveiled sweeping party platform recommendations Wednesday that—while falling short of progressive ambitions in a number of areas, from climate to healthcare—were applauded as important steps toward a bold and just policy agenda that matches the severity of the moment.
"We've moved the needle a lot, especially on environmental justice and upping Biden's ambition," said Sunrise Movement co-founder and executive director Varshini Prakash, a member of the Biden-Sanders Climate Task Force. "But there's still more work to do to push Democrats to act at the scale of the climate crisis."
The climate panel—co-chaired by Rep. Alexandria Ocasio-Cortez (D-N.Y.) and former Secretary of State John Kerry—recommended that the Democratic Party commit to "eliminating carbon pollution from power plants by 2035," massively expanding investments in clean energy sources, and "achieving net-zero greenhouse gas emissions for all new buildings by 2030."
In a series of tweets Wednesday night, Ocasio-Cortez—the lead sponsor of the House Green New Deal resolution—noted that the Climate Task Force "shaved 15 years off Biden's previous target for 100% clean energy."
"Of course, like in any collaborative effort, there are areas of negotiation and compromise," said the New York Democrat. "But I do believe that the Climate Task Force effort meaningfully and substantively improved Biden's positions."
Today the 6 Biden-Sanders Unity Task Forces are unveiling final language. The Climate Task Force accomplished a gr… https://t.co/gz3broq2qe— Alexandria Ocasio-Cortez (@Alexandria Ocasio-Cortez)1594240617.0
The 110 pages of policy recommendations from the six eight-person Unity Task Forces on education, the economy, criminal justice, immigration, climate change, and healthcare are aimed at shaping negotiations over the 2020 Democratic platform at the party's convention next month.
Sanders said that while the "end result isn't what I or my supporters would've written alone, the task forces have created a good policy blueprint that will move this country in a much-needed progressive direction and substantially improve the lives of working families throughout our country."
"I look forward to working with Vice President Biden to help him win this campaign," the Vermont senator added, "and to move this country forward toward economic, racial, social, and environmental justice."
Biden, for his part, applauded the task forces "for helping build a bold, transformative platform for our party and for our country."
"I am deeply grateful to Bernie Sanders for working with us to unite our party and deliver real, lasting change for generations to come," said the former vice president.
On the life-or-death matter of reforming America's dysfunctional private health insurance system—a subject on which Sanders and Biden clashed repeatedly throughout the Democratic primary process—the Unity Task Force affirmed healthcare as "a right" but did not embrace Medicare for All, the signature policy plank of the Vermont senator's presidential bid.
Instead, the panel recommended building on the Affordable Care Act by establishing a public option, investing in community health centers, and lowering prescription drug costs by allowing the federal government to negotiate prices. The task force also endorsed making all Covid-19 testing, treatments, and potential vaccines free and expanding Medicaid for the duration of the pandemic.
"It has always been a crisis that tens of millions of Americans have no or inadequate health insurance—but in a pandemic, it's potentially catastrophic for public health," the task force wrote.
Dr. Abdul El-Sayed, a former Michigan gubernatorial candidate and Sanders-appointed member of the Healthcare Task Force, said that despite major disagreements, the panel "came to recommendations that will yield one of the most progressive Democratic campaign platforms in history—though we have further yet to go."
We rein in #pharma's greed by: 1) Allowing Medicare to FINALLY negotiate Rx drugs FOR ALL AMERICANS 2) Using Rx d… https://t.co/6k9iUCLMp7— Abdul El-Sayed (@Abdul El-Sayed)1594238411.0
Observers and advocacy groups also applauded the Unity Task Forces for recommending the creation of a postal banking system, endorsing a ban on for-profit charter schools, ending the use of private prisons, and imposing a 100-day moratorium on deportations "while conducting a full-scale study on current practices to develop recommendations for transforming enforcement policies and practices at ICE and CBP."
Marisa Franco, director of immigrant rights group Mijente, said in a statement that "going into these task force negotiations, we knew we were going to have to push Biden past his comfort zone, both to reconcile with past offenses and to carve a new path forward."
"That is exactly what we did, unapologetically," said Franco, a member of the Immigration Task Force. "For years, Mijente, along with the broader immigrant rights movement, has fought to reshape the narrative around immigration towards racial justice and to focus these very demands. We expect Biden and the Democratic Party to implement them in their entirety."
"There is no going back," Franco added. "Not an inch, not a step. We must only move forward from here."
Reposted with permission from Common Dreams.
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By Emily Grubert
Natural gas is a versatile fossil fuel that accounts for about a third of U.S. energy use. Although it produces fewer greenhouse gas emissions and other pollutants than coal or oil, natural gas is a major contributor to climate change, an urgent global problem. Reducing emissions from the natural gas system is especially challenging because natural gas is used roughly equally for electricity, heating, and industrial applications.
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What RNG Is and Why it Matters<p>Most equipment that uses energy can only use a single kind of fuel, but the fuel might come from different resources. For example, you can't charge your computer with gasoline, but it can run on electricity generated from coal, natural gas or solar power.</p><p>Natural gas is almost pure methane, <a href="https://www.eia.gov/energyexplained/natural-gas/" target="_blank">currently sourced</a> from raw, fossil natural gas produced from <a href="https://www.eia.gov/energyexplained/natural-gas/where-our-natural-gas-comes-from.php" target="_blank">deposits deep underground</a>. But methane could come from renewable resources, too.</p><p><span></span>Two main methane sources could be used to make RNG. First is <a href="https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks" target="_blank">biogenic methane</a>, produced by bacteria that digest organic materials in manure, landfills and wastewater. Wastewater treatment plants, landfills and dairy farms have captured and used biogenic methane as an energy resource for <a href="http://emilygrubert.org/wp-content/uploads/2019/02/eia_860_2017_map.html" target="_blank">decades</a>, in a form usually called <a href="https://www.eia.gov/energyexplained/biomass/landfill-gas-and-biogas.php" target="_blank">biogas</a>.</p><p>Some biogenic methane is generated naturally when organic materials break down without oxygen. Burning it for energy can be beneficial for the climate if doing so prevents methane from escaping to the atmosphere.</p>
Renewable Isn’t Always Sustainable<p>If RNG could be a renewable replacement for fossil natural gas, why not move ahead? Consumers have shown that they are <a href="https://www.nrel.gov/analysis/green-power.html" target="_blank">willing to buy renewable electricity</a>, so we might expect similar enthusiasm for RNG.</p><p>The key issue is that methane isn't just a fuel – it's also a <a href="https://www.eia.gov/environment/emissions/ghg_report/ghg_overview.php" target="_blank">potent greenhouse gas</a> that contributes to climate change. Any methane that is manufactured intentionally, whether from biogenic or other sources, will contribute to climate change if it enters the atmosphere.</p><p>And <a href="http://doi.org/10.1126/science.aar7204" target="_blank">releases</a> <a href="https://doi.org/10.1016/j.wasman.2019.07.029" target="_blank">will happen</a>, from newly built production systems and <a href="https://theconversation.com/why-methane-emissions-matter-to-climate-change-5-questions-answered-122684" target="_blank">existing, leaky transportation and user infrastructure</a>. For example, the moment you smell gas before the pilot light on a stove lights the ring? That's methane leakage, and it contributes to climate change.</p><p>To be clear, RNG is almost certainly better for the climate than fossil natural gas because byproducts of burning RNG won't contribute to climate change. But doing somewhat better than existing systems is no longer enough to respond to the <a href="https://doi.org/10.1038/nclimate2923" target="_blank">urgency</a> of climate change. The world's <a href="https://www.ipcc.ch/sr15/chapter/spm/" target="_blank">primary international body on climate change</a> suggests we need to decarbonize by 2030 to mitigate the worst effects of climate change.</p>
Scant Climate Benefits<p><a href="https://iopscience.iop.org/article/10.1088/1748-9326/ab9335/meta" target="_blank">My recent research</a> suggests that for a system large enough to displace a lot of fossil natural gas, RNG is probably not as good for the climate as <a href="https://investor.southerncompany.com/information-for-investors/latest-news/latest-news-releases/press-release-details/2020/Southern-Company-Gas-grows-leadership-team-to-focus-on-climate-action-innovation-and-renewable-natural-gas-strategy/default.aspx" target="_blank">is publicly claimed</a>. Although RNG has lower climate impact than its fossil counterpart, likely high demand and methane leakage mean that it probably will contribute to climate change. In contrast, renewable sources such as wind and solar energy do not <a href="https://www.eia.gov/environment/emissions/carbon/" target="_blank">emit climate pollution directly</a>.</p><p>What's more, creating a large RNG system would require building mostly new production infrastructure, since RNG comes from different sources than fossil natural gas. Such investments are both long-term commitments and opportunity costs. They would devote money, political will and infrastructure investments to RNG instead of alternatives that could achieve a zero greenhouse gas emission goal.</p><p>When climate change first <a href="https://www.nytimes.com/1988/06/24/us/global-warming-has-begun-expert-tells-senate.html" target="_blank">broke into the political conversation</a> in the late 1980s, investing in long-lived systems with low but non-zero greenhouse gas emissions was still compatible with aggressive climate goals. Now, zero greenhouse gas emissions is the target, and my research suggests that large deployments of RNG likely won't meet that goal.</p>
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