View source for The Science of Earths Atmospheric Composition and Chemistry

== Introduction ==

The [[Earth's atmosphere|atmosphere]] is a critical component of the Earth system, providing the air we breathe and regulating the planet's climate. It is composed of several gases, including nitrogen, oxygen, and trace amounts of other gases. The chemistry of the atmosphere is complex and involves numerous physical and chemical processes that interact in intricate ways. Understanding the composition and chemistry of the atmosphere is essential for predicting weather, understanding climate change, and protecting human health and the environment.

[[Image:Detail-40427.jpg|thumb|center|A clear view of Earth's atmosphere from space, showing the blue sky and white clouds.|class=only_on_mobile]]
[[Image:Detail-40428.jpg|thumb|center|A clear view of Earth's atmosphere from space, showing the blue sky and white clouds.|class=only_on_desktop]]

== Composition of the Earth's Atmosphere ==

The Earth's atmosphere is primarily composed of nitrogen (78%) and oxygen (21%). The remaining 1% consists of argon (0.93%), carbon dioxide (0.04%), and trace amounts of other gases such as neon, helium, methane, krypton, and hydrogen, as well as water vapor. This composition is the result of billions of years of [[biogeochemical cycle|biogeochemical cycling]] and the life processes of organisms.

=== Nitrogen ===

Nitrogen is the most abundant gas in the atmosphere. It is a relatively inert gas and plays a crucial role in the [[Nitrogen cycle|nitrogen cycle]], a process vital for life on Earth.

=== Oxygen ===

Oxygen is the second most abundant gas in the atmosphere. It is essential for the process of [[Cellular respiration|cellular respiration]] in most living organisms and is a key component of the Earth's [[Ozone layer|ozone layer]].

=== Argon ===

Argon, a noble gas, is the third most abundant gas in the atmosphere. It is chemically inert and does not generally participate in atmospheric chemical reactions.

=== Carbon Dioxide ===

Carbon dioxide is a trace gas in the atmosphere but plays a significant role in Earth's [[Greenhouse effect|greenhouse effect]]. Its concentration in the atmosphere has been increasing due to human activities, primarily the burning of fossil fuels and deforestation.

=== Trace Gases ===

The atmosphere also contains trace amounts of other gases, including neon, helium, methane, krypton, and hydrogen. These gases are present in very small amounts but can have significant effects on the atmosphere's chemistry and climate.

== Atmospheric Chemistry ==

Atmospheric chemistry is the study of the chemical composition of the atmosphere, the sources and sinks of gases in the atmosphere, and the transformations that gases undergo. The field encompasses a wide range of studies, from the reactions of gases in the atmosphere to the impact of human activities on atmospheric composition.

=== Chemical Reactions in the Atmosphere ===

The atmosphere is a complex system of gases, particles, and radiation. Chemical reactions in the atmosphere can occur between gases, between gases and particles, and between gases and radiation. These reactions can change the composition of the atmosphere, influence the Earth's climate, and affect human health and the environment.

=== Human Influence on Atmospheric Chemistry ===

Human activities have a significant impact on the chemistry of the atmosphere. The burning of fossil fuels, industrial processes, and deforestation all release gases into the atmosphere that can alter its composition. These changes can have profound effects on the Earth's climate and the health of living organisms.

== See Also ==

* [[Climate change]]
* [[Air pollution]]
* [[Ozone depletion]]

[[Category:Atmospheric sciences]]
[[Category:Environmental chemistry]]
[[Category:Earth science]]
[[Category:random]]