Well the main Green house gases CO2, Methane etc will actually destroy the Ozone, build up a thick layer of gases in the atmosphere which will let heat and light in, but will trap most of it in. Which will cause the temperature to increase. But so etching that would cool down the Earths temperature, would be a series of volcanic eruptions which will block out the sun, out of thick layers of ash

Another theory would be to terra form so that we make astonishing amount of clouds to block out high amounts of light, but enough to let life on earth to continue

And if you look at Venus, it is extremely bright because of what you said, this stops light from getting in, but not the intense heat and radiation, therefore, if earth gained those types of clouds, we would be screwed

Note: I'm only 15 but I like to research these things in my spare time

Greenhouse gases causes more evaporation(heating of the earth's surface) making more clouds

Also clouds make the surface temperature cooler, especially at daytime.

Albedo also affects the formation of clouds. The indirect albedo via clouds makes the cloud's lifespan longer and causes lower precipitation.

From what I understand the answer is a mixed one; at night clouds have a noticeable warming effect, it is warmer on a cloudy night then on a clear night and during the day they have a cooling effect. Warmer temperatures will put more water vapour in the air so I think overall there is a positive (warming) feedback although actual climate scientist should be able to explain this a lot better then I can.

Clouds act both as insulators and reflectors of heat. This is why, during cloudy nights, it is usually warmer. That being said water vapour is also a greenhouse gas.

Warmer air parcels can hold more water vapour. In order for clouds to form that air parcel must cool until the maximum amount of water vapour that air parcel can hold is reached. In order for more clouds to form the water vapour level must grow faster than temperature increase. In reality less clouds are forming.

http://www.cloudsat.cira.colostate.edu/

http://isccp.giss.nasa.gov/products/onli...

While atmospheric water vapour concentration is increasing

http://disc.sci.gsfc.nasa.gov/data-holdi...

http://geotest.tamu.edu/userfiles/216/De...

when more cloud it will cause gloomy days as clouds dont let the heat to loose from the earth surface..it wont be sunny days but gloomy

There are arguments about this but general consensus is that clouds are more likely to have a slight cooling effect.

Clouds are water vapour, therefore do not exist in the minds of warmies.

Here's a science question.... If increases in greenhouse gases act to produce more CLOUDS, how would that change Earth's temperature?

So, will Earth get hot or cold... surface temperature wise?

btw, we are also suggesting that clouds are there due to an increase in Earth's albedo (reflectivity).