Have a look at these images below and you’ll find out how global warming looks like. It seems a bit contradict, but it’s true. Global warming might actually manifest by temperature going down, because of icebergs melting down and cold water getting into oceans, the temperature of water will get down and temperature of hot water streams such as Golf stream will get down, which will further effect global climate. It actually makes sense, but it’s still ironic! 
So if global warming means it will get cooler… Then shouldn’t we burn lots of fossil fuels so it won’t get warmer?! Because if warming the Earth makes things melt which cools it off, then cooling the earth should form ice which will heat it up!
View the “global dimming” docu online.