what's the role of the atmosphere and oceans on the average temperature on earth?

Question

I HAVE ANOTHER ONE.
how well can we predict the future changes in the earth system?
thanks

Answer 1

The atmosphere is an insulating blanket protecting the earth.The intensity of sun's radiation diminishes considerably while passing through the atmosphere.Absorption and scattering by the molecule matter such as dust and smoke,and reflection from clouds if present,all share in reducing the intensity of the down-ward moving solar radiation.Threfore the atmosphere keeps the temperature(hence the average temperature) within a tolerable limit.
For example, Mercury has no atmosphere.Its day time temperature is 430 degree celcius and night time temperature is --170(minus 170)
degree celcius.Such a large variation is due to absence of atmosphere.
Further the water vapour in the atmosphere controls the long-wave radiation(reflected radiation from the surface)balance of the atmosphere.The water vapour thus affects the heat balance conditions of the earth-atmosphere system by the powerful absorption of heat in the course of evaporation and sublimation from liquid water and ice and by the eventual release of the stored latent heat or hidden heat which is involved in the reverse process.
Ocean currents determine the climate of many continents as they mix the cold waters and warm waters of the oceans.For example,the Gulf stream makes the north west Europe much more temperate than any other region in the same latitude.So, the average temperature of many coastal countries in north west Europe are modified by the ocean current.
Global warming also has to be taken into consideration in predicting the future changes as the average global temperature is expected to increase by between one degree to 3.5 degree celcius by the year 2100 by global warming.

Answer 2

Main reason for the average temperature in most regions is the distance from the equator. But, temperature distribution though the ocean's currents play a big role too. Take, for example, cities located along the gulf coast. A city located closer to the Gulf allows for the warm ocean currents to moderate the temperatures (keeps temps warmer in the winter and cooler in the summer). Cities just a few hundred miles inland will have hotter summers and colder winters than city near the coast. There are other factors which act on the avereage temp such as terrain and elevation.