The vertical extend of the atmosphere is difficult to define, it surrounds the Earth and becomes increasingly thinner until at some point space is reached, 100 km is usually used as the border to space.
The lowest layer of the atmosphere is called the troposphere and contains almost all water vapor and approximately 75% of all molecular mass of the atmosphere, its height varies from 18 km at the equator to 8 km at the poles.
The sun warms the air or atmosphere indirectly, the Earth receives the solar radiation (insolation) and heats the lower layers of the atmosphere by means of radiation and convection. It is in this layer where we humans live, breathe, work and fly.
The composition of the atmosphere is important for sustainable life on this planet. In the lower part we find most of the weather creating circumstances so that life as we know it can prosper on this planet. This is a natural effect and its largely self regulating combined with the daily/night exposure to the sun due to the rotation of our planet.
This page looks at the several chemical elements found in our atmosphere, have fun!.
Found as vapor in the atmosphere below about 30000 ft, reaching levels from zero (poles) to 4% (tropical). Although small in quantity but its effect on weather can be dramatic. When water changes state from vapor to visible (water or ice) produces clouds, rain, fog and other phenomena it has a profound effect on temperature and humidity. Water vapor has its source from oceans, lakes, rivers, forest and plant, animal and human respiration.
Formed in the upper levels of the stratosphere and the lower levels of the mesosphere by the sun and blocks dangerous UV radiation which kills life as we know it on Earth. It consists of three oxygen molecules. The amount of ozone depends on the season, amount of solar radiation and some say certain human produced chemicals, which are banned these days.
Ozone also exists in the lower layers of the atmosphere (30 to 80 µg per m3) where its partly generated by the sun during the day (UV-A), thunderstorms (remember the fresh smell after one has passed through?) and ultraviolet radiation combined with molecules in the atmosphere. The amount varies with the seasons, more in summer less in winter.
Mislabelled by some as carbon (C), but there is no carbon gas. Carbon is a black solid, soot is carbon, diamonds are too (next to girls best friends). It is a colorless, heavy gas with no smell and not toxic until 5% or 50.000 ppm (Source: Hepple and Benson 2001). The molecular weight of carbon is 12 (plus a very small isotope fraction). The molecular weight of CO2 is 44. (2 oxygen at 16 is 32 plus 1 carbon at 12 is 44). It is produced by oxidation processes and expelled by breathing in humans (average 1 kg per day, or 40.000 ppm per exhale) and animal life, decomposing processes in the sea and the burning of fuels, wood and other materials containing carbon molecules.
Which is normal as this planet and everything on it is carbon based. This molecule consists of 13 parts of carbon and 32 parts of oxygen by weight.
Large amounts of carbon dioxide are dissolved in the oceans, plant life is also a major remover of this gas. They are made of carbohydrates (carbon, hydrogen, oxygen) living of the CO2 in the air. It is also known that the best food crop yields occur when plants are grown in atmospheres that are triple or quadruple current levels compared to our planet today (Source: http://wattsupwiththat.com/2011/01/06/co2-is-plant-food-clean-coal-say-watt/). Any level below 200 ppm and photosynthesis will shutdown.
A higher level encourages growth in plant life and is eventually converted into oxygen and food needed for humans. It is an essential gas for life on this planet. One could even come to the conclusion that the current levels are just enough to sustain plant life. Basically: without it there would be no life possible as we know it today. Trying to reduce it could be seen as a crime to humanity.
Click the next links for an impression of important CO2 levels or here for CO2 levels in the past and a CO2 timeline from 500 million years ago. Increasing CO2 levels results in even less effect in the atmosphere.
Off all the CO2 emitted in the atmosphere (0,041% / 410 ppm in 2019) only about 3% is of human origin (0,00123% / 12 ppm) (source EPA: EPA document supports that ~3% of atmospheric carbon dioxide is attributable to human sources ) and Earths Carbon Cycle in 2021. Worldwide aviation emissions results only 3% of all man made carbon dioxide in the atmosphere (0,000037% / 0,37 ppm).
On top of that: NASA and Science Daily concluded that CO2 even cools and greens the planet. (source: NASA Science News March 22, 2013 and Science Daily, July 2013: Deserts are greening from extra CO2 and CO2 fertilization . In 2019 the German 'Die WeltWoche' published an article about the greening of the planet , which means more food for animals and greater crop yields for humans.
Any attempt to remove the human origin part of this gas from the atmosphere will have absolutely no measurable effect at all on the climate. But financially, our economy will go bankrupt trying to accomplish this.
For a more detailed analysis of the human caused global warming or climate change see the next link as to why the Catastrophic Anthropogenic Global Warming hypothesis is falsified.
Like carbon dioxide, methane is a trace gas and with an amount of about 1,86 ppm (0,000186% @ 2019) it is not very abundant in our atmosphere. Its specific gravity is 0,55 (lighter than air) and specific heat is 1,305 so it heats and cools slower than air.
The amount of methane has increased from 1,7 ppm (1990) to 1,75 ppm in 1998, after which the amount added to the atmosphere has decreased reaching levels of around 1,8 ppm in 2010. (source WUWT: Methane Madness )
Even the amount of methane produced by cattle is totally moot with regard to global climate, read more on (source WUWT: cattle methane ).
Compared to CO2, methane oxidizes into carbon dioxide and water vapor on contact with oxygen and is quickly removed out of the atmosphere and the CO2 is consumed by plant growth and produces O2. Which is the reason why there is so little of it. The absorption spectra of both carbon dioxide and methane are overpowered by the far more abundant H2O.
The National Oceanic & Atmospheric Administration maintains a web page on these gases: click here to read up on that.Written by EAI.