Explain why,on Earth,the temperature decreases from the equator towards the poles.?

Answer 1

Angle of the sun increases as you go toward the pole. Sunlight is spread out more.

Answer 2

Due to the tilt in the earth's axis of rotation,there is an apparent movement of the sun between Northern and Southern hemisphere.This movement is restricted between the latitudes of 23.5 N and 23.5 S.This means, the sun will not be shining exactly overhead beyond these latitudes towards poles.Because of this,the sun's rays will fall in a slanting position,thereby passing through more atmosphere which will result less heating of the places toward the poles.
Secondly, due to the spherical shape of the earth, the same amount of sun's rays falling on a smaller area over the equator will fall on a larger area towards the poles,because of which the intensity of the solar radiation is reduced.
Thirdly,it is a known fact that warm air can hold more water vapour than a cold air.So the warm atmosphere over the equator traps more heat resulting in higher temperature whereas the cold air near the poles contain less moisture resulting in less temperature.
Finally,snow or ice is a good reflector of heat and a good radiator of long-wave(terrestial) radiations.Consequently,the temperature over snow or ice surface tends to sink,to very low levels.Not only this,the falling solar radiation may serve to melt the ice only, not raising its twmperature at all above the freezing point, over the poles.
Hence temperature decreases as you go towards poles.

Answer 3

The equator is closest to the sun.