Tag: heat and energy

The green house gas is $CO 2$.
A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs<a href="http://en.wikipedia.org/wiki/Absorption%28electromagnetic_radiation%29"> and emits radiation within the thermal infrared range. This process is the fundamental cause of the green house effect. The primary greenhouse gases in the Earth's atmophere are water vapor, $CO _2 $, $CH _4$ , nitrou oxide and Ozone.
Thus Option D is correct.

HFCs are coolants used in air conditioners and refrigerators that have a high global warming potential of about $10,000$.

This fluorinated gas absorbs the most heat over a hundred-year period. Its global warming potential is 23,500, compared to 28 for methane and 1 for carbon dioxide.

On average, methane lingers in the atmosphere for $12$ years, while $CO _2$ can remain for thousands of years.

Methane allows sunlight (shortwave radiation) to pass through the atmosphere freely, where it is then partially absorbed by the surface of the Earth. But some of this energy bounces back out towards space as heat. Of the heat emitted back to space, some is intercepted and absorbed by methane in the atmosphere. This molecular structure allows it to absorb some of the escaping heat and then re-emit it towards the Earth which increases global temperatures.

The greenhouse effect simply describes the fundamental role our atmosphere plays in sustaining life on Earth. Energy from the sun in the form of sunlight passes through our atmosphere and warms the surface of the Earth which then emits the energy back into the atmosphere in the form of infrared radiation. Greenhouse gases, which make up only about one per cent of the atmosphere, absorb and re-emit some of this heat, preventing much of it leaving the Earth's atmosphere. This keeps the blue planet at a comfy temperature to sustain life.
But over time, climate scientists argue, our atmosphere has accumulated more greenhouse gases, in particular carbon dioxide, methane, nitrous oxide and fluorocarbons. This increased concentration of atmospheric gases traps more heat close to the Earth's surface in the lower atmosphere and increases the average global temperature. This process, called the 'enhanced greenhouse effect', is fundamental to global warming.

These emissionsmostly from burning coal, oil, and natural gasaccounted for 82 percent of all U.S. greenhouse gases in 2013.

The green house gases absorb some of  the radiation (which is reflected by earth, clouds etc.) and the rest is passed into space. Due to that absorbed radiation, earth's atmosphere remains warm. If green house gases would absent, no radiation will stay on earth's atmosphere and temperature of atmosphere will go fall to approx. $-18^{o}C$ which will freeze all the water on earth. 

Global warming is caused primarily due to emission of carbon dioxide. Other pollutants contributing to global warming includes methane, nitrous oxide and CFCs.

Global warming has certain changes in weather that inturns changes rainfall patterns that increases disease,so only option incorrect is decreament in deseases.