Question

explain in detail how human activities are changing the composition and structure of the atmosphere. ANSWER PLEASE

Answer 1

Earth's atmosphere is composed of about 78% nitrogen, 21% oxygen, and 0.93% argon. The remainder, less than 0.1%, contains many small but important trace gases, including water vapor, carbon dioxide, and ozone. All of these trace gases have important effects on the earth's climate. The atmosphere can be divided into vertical layers determined by the way temperature changes with height. The layer closest to the surface is the troposphere, which contains over 80% of the atmospheric mass and nearly all the water vapor. The next layer, the stratosphere, contains most of the atmosphere's ozone, which absorbs highenergy radiation from the sun and makes life on the surface possible. Above the stratosphere are the mesosphere and thermosphere. These two layers include regions of charged atoms and molecules, or ions. Called the ionosphere, this region is important to radio communications, since radio waves can bounce off the layer and travel great distances. It is thought that the present atmosphere developed from gases ejected by volcanoes. Oxygen, upon which all animal life depends, probably built up as excess emissions from plants that produce it as a waste product during photosynthesis. Human activities may be affecting the levels of some important atmospheric components, particularly carbon dioxide and ozone.


Major gases

The most common atmospheric gas, nitrogen (chemical symbol N2) accounts for about 78% of the atmosphere. Nitrogen gas is largely inert, meaning that it does not readily react with other substances to form new chemical compounds. The next most common gas, oxygen (O2), makes up about 21% of the atmosphere. Oxygen is required for the respiration (breathing) of all animal life on Earth, from humans tobacteria. In contrast to nitrogen, oxygen is extremely reactive. It participates in oxidation, a type of chemical reaction that can be observed everywhere. Some common examples of oxidation are apples turning from white to brown after being sliced, the rusting of iron, and the very rapid oxidation reaction we call fire. Just under 1% of the atmosphere is made up of argon (Ar), which is a very inert noble gas, meaning that it does not take part in any chemical reactions under normal circumstances.

Together, these three gases account for 99.96% of the atmosphere. The remaining 0.04% contains a wide variety of trace gases, several of which are crucial to life on Earth.


Important trace gases

Carbon dioxide (CO2) affects the earth's climate and plays a large support role in the biosphere, the collection of living things that populate the earth's surface. Only about 0.0325% of the atmosphere is CO2. Carbon dioxide is required by plant life for photosynthesis, the process of using sunlight to store energy as simple sugars, upon which all life on Earth depends. Carbon dioxide is also one of a class of compounds called greenhouse gases. These gases are made up of molecules that absorb and emit infrared radiation, which we feel as heat. The solar energy radiated from the sun is mostly in the visible range, within a narrow band of wavelengths. This radiation is absorbed by the earth's surface, then reradiated back out to space not as visible light, but as longer wavelength infrared radiation. Greenhouse gas molecules absorb some of this radiation before it escapes to space, and re-emit some of it back toward the surface. In this way, these gases trap some of the escaping heat and increase the overall temperature of the atmosphere. If the atmosphere had no greenhouse gases, it is estimated that the earth's surface would be 90°F (32°C) cooler.



Read more: Composition Atmosphere and Structure - Atmospheric Structure, The Past And Future Of The Atmosphere - Composition of the atmosphere - JRank Articleshttp://science.jrank.org/pages/590/Atmosphere-Composition-Structure.html#ixzz4JriMQ4VJ

Answer 2

Answer:

Human activities are responsible for changing the structure and composition of the atmosphere due to the use of AC and refrigerators containing CFCs which is thinning the atmosphere and reducing it's ability to absorb harmful rays such as UV rays.

Explanation:

Hope it helps you