Oxygen - Global Overview
Let’s imagine a scenario of all species around the world – including humans – were suffocating and unable to breathe because oxygen levels had suddenly and precipitously dropped. Every single one would begin to panic. And then they'd do something, anything, to deal with the clear and present danger.
INTRODUCTION
Photosynthesis is arguably the most important set of chemical reactions on Earth. It is a process that occurs in plants and some microorganisms and results in the production of sugars. Plants produce their own food through the process of photosynthesis.
The products of photosynthesis are a source of energy for plants, animals, and almost all other living things. Photosynthesis also leads to an increase in the concentration of oxygen in the atmosphere. It takes six molecules of CO2 to produce one molecule of glucose by photosynthesis, and six molecules of oxygen are released as a by-product. Without photosynthesis, animals would never have evolved because the oxygen we need to breathe and survive would not be present in the air or oceans.
Photosynthesis is a set of chemical reactions that uses energy from the sun and carbon dioxide to produce sugar and oxygen. The sugar provides plants with energy to grow, and the plant material provides food for grazing animals.
When plants die their leaves, stems and roots are food sources for decomposers such as fungi and bacteria. Photosynthesis, therefore, supports entire ecosystems by providing energy which cascades down from plants and algae to animals, fungi and other microorganisms.
How much oxygen does a person need?
A human breathes about 9.5 tonnes of air in a year, but oxygen only makes up about 23 percent of that air (by mass), and we only extract a little over a third of the oxygen from each breath. That works out to a total of about 740kg of oxygen per year. Which is, very roughly, seven or eight trees’ worth. So one person, needs around 7 to 8 grown trees to have enough oxygen to breath.
Oxygen, is the most abundant chemical element on Earth. However, due to climate change and man-made activities problems are arising. Tropical rainforests produce 40% of the Earth’s oxygen even though they cover only 7% of our land. It is estimated that trees in tropical rainforests lower the planet’s temperature around -15 degrees Celsius. In just 40 years we have lost half of all our rainforests, the equivalent of Europe. And we are losing 27 soccer fields of rainforest every minute.
The upcoming plans for The Netherlands with deforestation are not looking good, as 1231 hectares will be logged and only 304 hectares will be newly planted.
You can see where problems can rise.
What are our forests really made of? From the air, ecologist Greg Asner uses a spectrometer and high-powered lasers to map nature in meticulous kaleidoscopic 3D detail -- what he calls "a very high-tech accounting system" of carbon. In this fascinating talk, Asner gives a clear message: To save our ecosystems, we need more data, gathered in new ways.
In the last 50 years, the amount of water in the open ocean with zero oxygen has gone up more than fourfold. In coastal water bodies, including estuaries and seas, low-oxygen sites have increased more than 10-fold since 1950. Scientists expect oxygen to continue dropping even outside these zones, as Earth warms.
Oxygen is as crucial to life in the oceans as it is to human beings and species living on land. But while humans are able to spot when smog or air pollution creates suffocating conditions in capital cities like Beijing – and demand from theirs leaders, to clean the toxic air – hardly anyone is on hand to observe species suffocating or struggling with similar oxygen depletion in oceans.
A study, published in Science, is the first one to take a closer look on "dead zones" which have increased fourfold, and "low-oxygen zones" tenfold, since the 1950s. These areas now cover more than 31 million square kilometers of ocean and extend as much as 200 meters below sea level – an area that is larger than North America or Africa. Much of it is being driven by climate change and industrial pollution.
Ocean expert Nancy Rabalais tracks the ominously named "dead zone" in the Gulf of Mexico -- where there isn't enough oxygen in the water to support life. The Gulf has the second largest dead zone in the world; on top of killing fish and crustaceans, it's also killing fisheries in these waters.
Many scientist have also focused on coral reefs and their important role. This study on dying coral reefs is important – showcasing the impacts that climate change and warmer oceans are having on living ecosystems in the oceans. The important role of the ocean system is rapidly losing its ability to provide basic, life-sustaining elements for every species living in the seas.
It is no surprise to scientists that warming oceans are losing oxygen, but the scale of the dip calls for urgent attention. Oxygen levels in some tropical regions have dropped by a startling 40 percent in the last 50 years, some recent studies reveal. Levels have dropped more subtly elsewhere, with an average loss of 2 percent globally.
"Desertification is a fancy word for land that is turning to desert," begins Allan Savory in this quietly powerful talk. And terrifyingly, it's happening to about two-thirds of the world's grasslands, accelerating climate change and causing traditional grazing societies to descend into social chaos. Savory has devoted his life to stopping it.
TOPICS We’re discussing
This week at The Conscious club we will be discussing about topics related to oxygen depletion and air in general:
Oxygen & Deforestation
Oxygen & Ocean
Oxygen & Pollution
Oxygen & Sick Building Syndrome
Oxygen & Deforestation
Each year, 119 to 150 million square kilometers of forest are lost due to deforestation - the removal of trees from the land by man-made and natural events. The main cause of deforestation are due to agriculture (80%), logging (14%), firewood (5) and other purposes (1%). The loss of trees has an adverse effect on the air we breath.
Without trees, humans would not be able survive because the air would be unsuitable for breathing. If anything, without oxygen, we will have to develop some kind of gas masks that will be able to filter the little oxygen that would be left in the air.
"Save the rainforest" is an environmental slogan as old as time - but Tasso Azevedo catches us up on how the fight is actually going these days. Spurred by the jaw-dropping losses of the 1990s, new laws (and transparent data) are helping slow the rate of deforestation in Brazil.
Oxygen & Ocean
You breathe because you need oxygen, a gas which makes up 21 percent of the Earth’s atmosphere. All that oxygen has to come from somewhere. You might already know that it comes from photosynthetic organisms like plants. But did you know that most of the oxygen you breathe comes from organisms in the ocean?
That’s right—more than half of the oxygen you breathe comes from marine photosynthesizers, like phytoplankton and seaweed. Both use carbon dioxide, water and energy from the sun to make food for themselves, releasing oxygen in the process. In other words, they photosynthesize. And they do it in the ocean. Unfortunately climate change is causing large-scale ocean deoxygenation, as warmer waters hold less oxygen.
Oxygen & Pollution + Air Quality
Air pollution is a mix of particles and gases that can reach harmful concentrations both outside and indoors. Its effects can range from higher disease risks to rising temperatures.
9 out of 10 people worldwide breathe in polluted air. Many hazardous pollutants such as, carbon oxides, Nitrogen, Sulfur and Lead can be found in the air we breath. This bad outdoor air caused an estimated 4.2 million premature deaths in 2016.
Oxygen & Sick Building Syndrome
Indoor Air Quality (IAQ) refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants. Understanding and controlling common pollutants indoors can help reduce your risk of indoor health concerns.
The term "sick building syndrome" (SBS) is used to describe situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified. The complaints may be localized in a particular room or zone, or may be widespread throughout the building.
Indoor air pollution involves exposures to particulates, carbon oxides, and other pollutants carried by indoor air or dust.
Sources:
https://www.usnews.com/news/at-the-edge/articles/2018-01-26/oxygen-levels-in-oceans-are-dropping-dangerously
https://www.scientificamerican.com/article/the-ocean-is-running-out-of-breath-scientists-warn/
https://phys.org/news/2018-01-broadest-view-world-oxygen-scientists.html
https://www.universityofcalifornia.edu/news/ocean-losing-its-breath
https://www.sciencefocus.com/planet-earth/how-many-trees-does-it-take-to-produce-oxygen-for-one-person/
https://www.thoughtco.com/reasons-living-trees-are-valuable-1343514
https://www.thoughtco.com/trees-importance-and-environmental-benefit-1342855
https://www.lemonde.fr/les-decodeurs/article/2019/02/26/neuf-idees-recues-sur-la-pollution-de-l-air_5428456_4355770.html
https://earthsky.org/earth/how-much-do-oceans-add-to-worlds-oxygen
https://science.sciencemag.org/content/359/6371/eaam7240
Film: Our Planet (2019), Chasing Coral (2017)