Greenhouse+Gases+continued...

Greenhouse Gases 2: Water Vapor, Ozone and Nitrous Oxide By: Courtney Ellis Water Vapor: -Water vapor is totally invisible, it is water in its gaseous form. -It is the Earth's most important greenhouse gas, giving us over 90% of the Earth's natural greenhouse effect -When liquid water is evaporated to form water vapor, heat is absorbed,this helps to cool the surface of the Earth. -This "latent heat of condensation" is released again when the w ater vapor condenses to form cloud water. - Water Vapor is of 99.999% natural origin and contributes to 95% of the Greenhouse effect. Meaning that the effeorts that humans are making to reduce global warming are not going to have much affect in the long run because water vapor will always be created. Water vapor overwhelms all other natural and man-made greenhouse contributions. -However, it does make sense to say that man can do somethingfor reducing water vapor because the warmer air from all these emissions contains more water vapor.
 * Water Vapor is a natural Greenhouse gas, this graph shows this and how it is the top contributer to the greenhouse effect: **



Nitrous Oxide: - Nitrous Oxide is a colorless greenhouse gas. - It is used as an anesthetic and is preimarily known as laughing gas (someting you might receive at the dentist). -This gas is released naturally from oceans and by bacteria in soils. - It's levels in the atmosphere have been rising over the past 350 years. - Human causes of this gas into the atmosphere are: -nitrogen based fertilizers - disposing of waste into sewage treatment plants - automobile exhaust - other sources not yet identified -The emissions that we are emmitting today will be trapped in the atmosphere for **100 years**! (this is why it is important to reduce these emmissions as much as possible). -Since 1750, the nitrous oxide level has risen 15%, which is man induced. -**However**..... nitrous oxide emmissions are still 95.067% natural (which we can do nothing about):



Ozone: - Ozone acts as both a direct greenhouse gas and as an indirect controller of greenhouse gas lifetimes. -As a a direct greenhouse gas it is thought to have caused around 1/3 of all the direcy greenhouse induced warming since the industrial revolution. -Ozone is a tough gas to keep track of mainly because of its short lifespan and its concentrations vary from place to place. -Currently the estimate for the amount of global tropospheric ozone is 370 million tonnes. - Ozone is produced in the stratosphere by influx and sometimes the troposhere by photochemical reactions. These reactions are increasing with increasing amounts of air pollution. - One good thing about Ozone is the affect it has on the lifetimes of other greenhouse gases. The breakdown of trpospheric ozone in sunlight produces OH radicals which mop up other greenhouse gases such as methane. This inturn helps reduce the global warming potential. -Humans have put more ozone into the atmosphere via biomass and fossilfuel burning. -Most of mans contribution to the ozone increase is detected from cities. -In an effort to reduce these increases of ozone we can do the following: reduce pollution from man-made sources such as biomass burning, man-made sources and transport. -Until we take the step to reduce thses emmisions however we can say that troposheric ozone will remain a powerful greenhouse gas whose concentration has been raised by man.

Top Pictures Provided By: [], [], [] Two Graphs provided By: [] Information provided By: []

[] []