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Amazon fires are destructive, but they aren’t depleting Earth’s oxygen supply
Contrary to popular belief, the Amazon rainforest does not produce 20% of our planet's oxygen.
Fires in the Amazon rainforest have captured attention worldwide in recent days. Brazilian President Jair Bolsonaro, who took office in 2019, pledged in his campaign to reduce environmental protection and increase agricultural development in the Amazon, and he appears to have followed through on that promise.
The resurgence of forest clearing in the Amazon, which had decreased more than 80% following a peak in 2004, is alarming for many reasons. Tropical forests harbor many species of plants and animals found nowhere else. They are important refuges for indigenous people, and contain enormous stores of carbon as wood and other organic matter that would otherwise contribute to the climate crisis.
Some media accounts have suggested that fires in the Amazon also threaten the atmospheric oxygen that we breathe. French President Emmanuel Macron tweeted on Aug. 22 that “the Amazon rain forest – the lungs which produces 20% of our planet's oxygen – is on fire."
The oft-repeated claim that the Amazon rainforest produces 20% of our planet's oxygen is based on a misunderstanding. In fact nearly all of Earth's breathable oxygen originated in the oceans, and there is enough of it to last for millions of years. There are many reasons to be appalled by this year's Amazon fires, but depleting Earth's oxygen supply is not one of them.
Oxygen from plants
As an atmospheric scientist, much of my work focuses on exchanges of various gases between Earth's surface and the atmosphere. Many elements, including oxygen, constantly cycle between land-based ecosystems, the oceans and the atmosphere in ways that can be measured and quantified.
Nearly all free oxygen in the air is produced by plants through photosynthesis. About one-third of land photosynthesis occurs in tropical forests, the largest of which is located in the Amazon Basin.
But virtually all of the oxygen produced by photosynthesis each year is consumed by living organisms and fires. Trees constantly shed dead leaves, twigs, roots and other litter, which feeds a rich ecosystem of organisms, mostly insects and microbes. The microbes consume oxygen in that process.
Forest plants produce lots of oxygen, and forest microbes consume a lot of oxygen. As a result, net production of oxygen by forests – and indeed, all land plants – is very close to zero.
There are four main reservoirs of oxygen on Earth: the terrestrial biosphere (green), marine biosphere (blue), lithosphere (Earth's crust, brown), and atmosphere (grey). Colored arrows show fluxes between these reservoirs. Burial of organic material causes a net increase in atmospheric oxygen, and reactions with minerals in rocks cause a net decrease.
Oxygen production in the oceans
For oxygen to accumulate in the air, some of the organic matter that plants produce through photosynthesis must be removed from circulation before it can be consumed. Usually this happens when it is rapidly buried in places without oxygen – most commonly in deep sea mud, under waters that have already been depleted of oxygen.
This happens in areas of the ocean where high levels of nutrients fertilize large blooms of algae. Dead algae and other detritus sink into dark waters, where microbes feed on it. Like their counterparts on land, they consume oxygen to do this, depleting it from the water around them.
Below depths where microbes have stripped waters of oxygen, leftover organic matter falls to the ocean floor and is buried there. Oxygen that the algae produced at the surface as it grew remains in the air because it is not consumed by decomposers.
Tiny phytoplankton in the ocean generate half of the oxygen produced on Earth.
This buried plant matter at the bottom of the ocean is the source of oil and gas. A smaller amount of plant matter gets buried in oxygen-free conditions on land, mostly in peat bogs where the water table prevents microbial decomposition. This is the source material for coal.
Only a tiny fraction – perhaps 0.0001% – of global photosynthesis is diverted by burial in this way, and thus adds to atmospheric oxygen. But over millions of years, the residual oxygen left by this tiny imbalance between growth and decomposition has accumulated to form the reservoir of breathable oxygen on which all animal life depends. It has hovered around 21% of the volume of the atmosphere for millions of years.
Some of this oxygen returns to the planet's surface through chemical reactions with metals, sulfur and other compounds in Earth's crust. For example, when iron is exposed to air in the presence of water, it reacts with oxygen in the air to form iron oxide, a compound commonly known as rust. This process, which is called oxidation, helps regulate oxygen levels in the atmosphere.
Don't hold your breath
Even though plant photosynthesis is ultimately responsible for breathable oxygen, only a vanishingly tiny fraction of that plant growth actually adds to the store of oxygen in the air. Even if all organic matter on Earth were burned at once, less than 1% of the world's oxygen would be consumed.
In sum, Brazil's reversal on protecting the Amazon does not meaningfully threaten atmospheric oxygen. Even a huge increase in forest fires would produce changes in oxygen that are difficult to measure. There's enough oxygen in the air to last for millions of years, and the amount is set by geology rather than land use. The fact that this upsurge in deforestation threatens some of the most biodiverse and carbon-rich landscapes on Earth is reason enough to oppose it.
- Why it matters that the Amazon is on fire - Big Think ›
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Can an orgasm a day really keep the doctor away?
- Achieving orgasm through masturbation provides a rush of feel-good hormones (such as dopamine, serotonin and oxytocin) and can re-balance our levels of cortisol (a stress-inducing hormone). This helps our immune system function at a higher level.
- The surge in "feel-good" hormones also promotes a more relaxed and calm state of being, making it easier to achieve restful sleep, which is a critical part in maintaining a high-functioning immune system.
- Just as bad habits can slow your immune system, positive habits (such as a healthy sleep schedule and active sex life) can help boost your immune system which can prevent you from becoming sick.
How masturbation affects your brain...<p>Orgasms are a very common human phenomenon. The physical and mental health benefits have been researched frequently as a result, and yet, there is still so much to be learned about how our bodies and brains react to the chemicals and hormones released during and after experiencing this type of sexual release.</p><p>"The amount of speculation versus actual data on both the function and value of orgasm is remarkable" explains Julia Heiman, director of the <a href="https://kinseyinstitute.org/" target="_blank">Kinsey Institute for Research in Sex, Gender, and Reproduction</a>.</p><p>Masturbation causes a rush of <a href="https://www.webmd.com/mental-health/what-is-dopamine" target="_blank">dopamine</a>, which is a chemical that is associated with our ability to feel pleasure. Along with the rush of dopamine that is released during an orgasm, there is also a release of a hormone called <a href="https://www.livescience.com/42198-what-is-oxytocin.html" target="_blank">oxytocin</a>, which is commonly referred to as the "love hormone."<br></p><p>This concoction of chemicals does more than just boost our mood, it also can play a key role in decreasing stress and promoting relaxation. Oxytocin decreases <a href="https://www.webmd.com/a-to-z-guides/what-is-cortisol" target="_blank">cortisol</a>, which is a stress hormone that is usually present (in high volumes) during times of anxiety, fear, panic, or distress. </p><p>According to BDSM and fetish researcher <a href="https://www.psychologytoday.com/us/therapists/dr-gloria-brame-colbert-ga/278388" target="_blank">Dr. Gloria Brame</a>, an orgasm is the biggest non-drug induced blast of dopamine that we can experience. </p><p>By boosting the oxytocin and dopamine levels and subsequently decreasing our cortisol levels, the brain is placed in a more relaxed, euphoric, and calm state. </p>
Masturbation boosts your immune system and raises your white blood cell count.<p>How do those effects on the brain from reaching orgasm translate to boosting our immune system and making our body healthier?</p><p>The increase of oxytocin and dopamine that causes a decrease in cortisol levels can help boost our immune system because cortisol (well-known for being a stress-inducing hormone) actually helps maintain your immune system if released in small doses. </p><p>According to <a href="https://www.health24.com/Sex/Great-sex/incredible-health-benefits-to-masturbating-20181030-2" target="_blank">Dr. Jennifer Landa</a>, a hormone-therapy specialist, masturbation can produce the right kind of environment for a strengthened immune system to thrive. </p><p><a href="https://www.ncbi.nlm.nih.gov/pubmed/15316239" target="_blank">A study</a> conducted by the Department of Medical Psychology at the University Clinic of Essen (in Germany) showed similar results. A group of 11 volunteers were asked to participate in a study that would look at the effects of orgasm through masturbation on the white blood cell count and immune system.</p><p>During this experiment, the white blood cell count of each participant was analyzed through measures that were taken 5 minutes before and 45 minutes after reaching a self-induced orgasm. </p><p>The results confirmed that sexual arousal and orgasm increased the number of white blood cells, particularly the natural killer cells that help fight off infections. </p><p>The findings confirm that our immune system is positively affected by sexual arousal and self-induced orgasm and promote even more research into the positive impacts of sexual arousal and orgasm. </p>
Masturbation can ease and prevent pain, which allows you to achieve the restful sleep that helps your immune system stay strong and healthy.<p>The benefits of masturbation have long been debated, but the more research that is done on the topic the more we understand that there are many positive reactions that happen in our bodies and brains when we orgasm.</p><p>Orgasms can help prevent or mitigate pain, which boosts the immune system, preventing cold and flu symptoms. </p><p>According to neurologist and headache specialist Stefan Evers, about one in three patients experience relief from migraine attacks by experiencing sexual activity or orgasm. Evers and his team <a href="https://www.livescience.com/27642-sex-relieves-migraine-pain.html" target="_blank">conducted an experiment</a> with 800 migraine patients and 200 patients who suffered from cluster-headaches to see how their experiences with sexual activity impacted their pain levels. </p><p>The study showed that 60% of migraine sufferers experienced pain relief after participating in sexual activity that resulted in orgasm. Of the cluster-headache sufferers, about 50% said their headaches actually worsened after sexual arousal and orgasm. </p><p>Evers suggested in his findings that the people who did not experience pain relief from migraines of headaches during their sexual activity did not release as large amounts of endorphins as those who did experience pain relief. </p><p>According to <a href="https://www.sharecare.com/health/chronic-pain/chronic-pain-affect-immune-system" target="_blank">rheumatologist Dr. Harris McIlwain</a>, people who suffer from chronic pain have immune systems that are simply not functioning at full capacity - therefore, alleviating pain (through orgasm, as an example) can help boost the immune system. </p><p>Orgasms can also promote relaxation and make it easier to fall asleep. Serotonin, oxytocin, and norepinephrine are all hormones that are released during sexual arousal and orgasm, and all three are known for counteracting stress hormones and promoting relaxation, which makes it much easier for you to fall asleep.</p><p>There are <a href="https://www.ncbi.nlm.nih.gov/pubmed/1233384" target="_blank">several studies</a> showing that serotonin and norepinephrine help our body cycle through REM and deep non-REM sleeping cycles. During these sleep cycles, the immune system releases proteins called <a href="https://www.sleepfoundation.org/articles/how-sleep-affects-your-immunity" target="_blank"><span id="selection-marker-1" class="redactor-selection-marker"></span>cytokines<span id="selection-marker-2" class="redactor-selection-marker"></span></a>, which target infection and inflammation. This is a critical part of our immune response. Cytokines are both produced and released throughout our bodies while we sleep, which proves the importance of a good sleep schedule to a healthy immune system.</p>
Masturbation promotes a high-functioning immune system; a healthy immune system prevents cold and flu.<p>The immune system is a balanced network of cells and organs that work together to defend you against infections and diseases by stopped threats like bacteria and viruses from entering your system. While there are many things we need to do to keep our immune systems functioning at optimal levels, masturbation (or other means of achieving orgasm) has proven to have positive effects on the immune system as a whole.</p><p>Just as bad habits (such as an inconsistent sleep schedule or harmful chemicals in your body) can slow your immune system, positive habits (such as a healthy sleep schedule and active sex life) can help boost your immune system. </p>
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Professor Luis Escobar.
Credit: Virginia Tech