What type of gases are in the atmosphere

The majority of the mass of the entire atmosphere is contained in the troposphere—between approximately 75 and 80 percent. Temperatures in the troposphere decrease with altitude. It reaches from the top of the troposphere, which is called the tropopause, to an altitude of approximately 50 kilometers 30 miles.

Temperatures in the stratosphere increase with altitude. A high concentration of ozone, a molecule composed of three atoms of oxygen, makes up the ozone layer of the stratosphere. This ozone absorbs some of the incoming solar radiation, shielding life on Earth from potentially harmful ultraviolet UV light, and is responsible for the temperature increase in altitude.

The top of the stratosphere is called the stratopause. Temperatures decrease in the mesosphere with altitude. The thermosphere is located above the mesopause and reaches out to around kilometers miles.

Not much is known about the thermosphere except that temperatures increase with altitude. The uppermost layer, that blends with what is considered to be outer space, is the exosphere. Also called a shooting star or falling star. The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit.

The Rights Holder for media is the person or group credited. 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. Its part in the enhancement of the greenhouse effect is minor relative to the other greenhouse gases already mentioned. However, it does have an important role in the artificial fertilization of ecosystems.

In extreme cases, this fertilization can lead to the death of forests, eutrophication of aquatic habitats, and species exclusion. Sources for the increase of nitrous oxide in the atmosphere include: land-use conversion; fossil fuel combustion; biomass burning; and soil fertilization. Most of the nitrous oxide added to the atmosphere each year comes from deforestation and the conversion of forest, savanna and grassland ecosystems into agricultural fields and rangeland.

Both of these processes reduce the amount of nitrogen stored in living vegetation and soil through the decomposition of organic matter. Nitrous oxide is also released into the atmosphere when fossil fuels and biomass are burned. However, the combined contribution to the increase of this gas in the atmosphere is thought to be minor. The use of nitrate and ammonium fertilizers to enhance plant growth is another source of nitrous oxide. How much is released from this process has been difficult to quantify.

Ozone's role in the enhancement of the greenhouse effect has been difficult to determine. In , methane CH 4 accounted for about 10 percent of all U.

Human activities emitting methane include leaks from natural gas systems and the raising of livestock. Methane is also emitted by natural sources such as natural wetlands. In addition, natural processes in soil and chemical reactions in the atmosphere help remove CH 4 from the atmosphere.

Methane's lifetime in the atmosphere is much shorter than carbon dioxide CO 2 , but CH 4 is more efficient at trapping radiation than CO 2.

Pound for pound, the comparative impact of CH 4 is 25 times greater than CO 2 over a year period. Globally, percent of total CH 4 emissions come from human activities.

Methane is also emitted from a number of natural sources. Natural wetlands are the largest source, emitting CH 4 from bacteria that decompose organic materials in the absence of oxygen.

Smaller sources include termites, oceans, sediments, volcanoes, and wildfires. To find out more about the role of CH 4 in warming the atmosphere and its sources, visit the Climate Change Indicators page. Methane emissions in the United States decreased by 15 percent between and During this time period, emissions increased from sources associated with agricultural activities, while emissions decreased from sources associated with landfills, coal mining, and from natural gas and petroleum systems.

There are a number of ways to reduce CH 4 emissions. Some examples are discussed below. EPA has a series of voluntary programs for reducing CH 4 emissions, in addition to regulatory initiatives. EPA also supports the Global Methane Initiative , an international partnership encouraging global methane reduction strategies. Upgrading the equipment used to produce, store, and transport oil and natural gas can reduce many of the leaks that contribute to CH 4 emissions. Methane from coal mines can also be captured and used for energy.

Methane from manure management practices can be reduced and captured by altering manure management strategies. Additionally, modifications to animal feeding practices may reduce emissions from enteric fermentation. Because CH 4 emissions from landfill gas are a major source of CH 4 emissions in the United States, emission controls that capture landfill CH 4 are an effective reduction strategy. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K. Averyt, M.

Tignor and H. Miller eds. Cambridge University Press. Cambridge, United Kingdom pp. In , nitrous oxide N 2 O accounted for about 7 percent of all U. Human activities such as agriculture, fuel combustion, wastewater management, and industrial processes are increasing the amount of N 2 O in the atmosphere.

Nitrous oxide is also naturally present in the atmosphere as part of the Earth's nitrogen cycle, and has a variety of natural sources. The other planets in our solar system also have an atmosphere, but none of them have the same ratio of gases and layered structure as Earth's atmosphere. The atmosphere also includes water vapor.

There are also many small particles - solids and liquids - "floating" in the atmosphere. These particles, which scientists call "aerosols", include dust, spores and pollen, salt from sea spray, volcanic ash, smoke, and more.

The atmosphere grows thinner less dense and lower in pressure as one moves upward from Earth's surface. It gradually gives way to the vacuum of outer space. There is no precise "top" of the atmosphere. Air becomes so thin at altitudes between and km miles up that for many purposes that range of heights can be considered the boundary between the atmosphere and space.