<em>air moves because of two reasons..
1 temperature difference
2 pressure difference
<u>1 temperature difference :
</u> when there is temperature difference in the atmosphere ,,hot air rises and cold air takes its place ... so movement of air occurs..
<u>2 pressure difference:
</u><u /> also when there is pressure difference in atmosphere ,, air moves away from the area where there is more pressure..
<u>if there is no temperature and pressure difference then air will not move...
</u>
</em>
<em>it took <u>130 years </u> to build Sagrada familia... :) it build from <u>1852 to 1926...</u>
</em>
The greenhouse effect is the rise in temperature that the Earth experiences because certain gases in the atmosphere (water vapor, carbon dioxide, nitrous oxide, and methane, for example) trap energy from the sun. Normal warming is mostly caused by natural gases.
