IS THIS GLOBAL WARMING OR NOT?

I am fascinated by the subject of climate change but question the scientists regarding global warming.There is no doubt the climate is changing and there is enough evidence to indicate we are responsible for this by our abuse of the planets resources and our relentless pollution.However,my question is have the experts got it right? I know currently the temperatures are climbing but it this just a short term symptom before we start actually cooling. We know millions of tons of ice are melting and falling into the sea every day as a result of the increases in global temperatures.However, surely this will in turn eventually cause major cooling of our Oceans. This again will then cool the atmosphere and bring colder conditions not warmer conditions. OK we all know about the green house effect but again what if this works in the opposite way and again by blocking out the sun actually causes less heat eventually. More over cast conditions added to the extra moisture now being generated from the increased sea levels and cooler sea water could actually cause the temperatures to drop. Some scientists have already renamed it global dimming. Now let me emphasize here I am asking the question and not making a statement as I have no idea if I am correct.This is just a wild theory. It is just curious that if I take a bottle of milk from our deep freeze and try to thaw it in hot tap water in the sink the tap water goes cold while the milk still stays solid for ages after. It can take hours to thaw out a 2 litre milk container. I would really be interested in other opinions on this subject.