The human-caused increase in its concentration in the atmosphere has strengthened the greenhouse effect and has definitely contributed to global warming over the last years. Carbon dioxide is also naturally exchanged between the atmosphere and life through the processes of photosynthesis and respiration. Methane is a very strong greenhouse gas. The primary sources for the additional methane added to the atmosphere in order of importance are: rice cultivation; domestic grazing animals; termites; landfills; coal mining; and, oil and gas extraction.
Anaerobic conditions associated with rice paddy flooding results in the formation of methane gas. However, an accurate estimate of how much methane is being produced from rice paddies has been difficult to ascertain.
Nevertheless, scientists believe that the contribution of rice paddies is large because this form of crop production has more than doubled since Grazing animals release methane to the environment as a result of herbaceous digestion. Some researchers believe the addition of methane from this source has more than quadrupled over the last century.
Termites also release methane through similar processes. Land-use change in the tropics, due to deforestation, ranching, and farming, may be causing termite numbers to expand. If this assumption is correct, the contribution from these insects may be important. Methane is also released from landfills, coal mines, and gas and oil drilling. Landfills produce methane as organic wastes decompose over time.
Coal, oil, and natural gas deposits release methane to the atmosphere when these deposits are excavated or drilled.
The average concentration of the greenhouse gas nitrous oxide is now increasing at a rate of 0. That makes it harder for a person to breathe and get enough oxygen to live, although there is evidence for microbial life high up in the clouds. Related: How Big is Earth? Earth's atmosphere is divided into five main layers: the exosphere, the thermosphere, the mesosphere, the stratosphere and the troposphere, according to NASA. The atmosphere thins out in each higher layer until the gases dissipate in space.
There is no distinct boundary between the atmosphere and space, but an imaginary line about 62 miles kilometers from the surface, called the Karman line , is usually where scientists say atmosphere meets outer space. The troposphere is the layer closest to Earth's surface. It is 4 to 12 miles 7 to 20 km thick and contains half of Earth's atmosphere. Air is warmer near the ground and gets colder higher up. Nearly all of the water vapor and dust in the atmosphere are in this layer and that is why clouds are found here.
The stratosphere is the second layer. It starts above the troposphere and ends about 31 miles 50 km above ground. Ozone is abundant here and it heats the atmosphere while also absorbing harmful radiation from the sun. The air here is very dry, and it is about a thousand times thinner here than it is at sea level. Because of that, this is where jet aircraft and weather balloons fly.
The mesosphere starts at 31 miles 50 km and extends to 53 miles 85 km high. The top of the mesosphere, called the mesopause, is the coldest part of Earth's atmosphere, with temperatures averaging about minus degrees F minus 90 C. Incomplete combustion of fossil fuels.
Forms lower level ozone, harms respiratory system. Photochemical reactions. Damages plants. Sulfur Oxides. SO2, SO3. Combusting of sulfur-containing fuels — e. Impairs breathing, asthma and bronchitis. Particulate Matter. Affects visibility, respiratory system. Organic Processes. Secondary greenhouse gas. Water Vapor.
Combustion processes, Evaporation. The Atmosphere and Air Pressure The miles km long column of air making up the atmosphere exerts its weight pressing downward under the force of gravity. Guy Brasseur. We are called to be architects of the future, not its victims. Buckminster Fuller. Skip to main content. Definition The particles and the concentrations of the particles in the protective envelope surrounding the Earth.
Summary The composition of the atmosphere - its gases and particles - plays a critical role in connecting human welfare with global and regional changes because the atmosphere links all of the principal components of the Earth system.
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