The 1990s were even hotter, and the 2000s hotter still -- at an increasing rate despite a natural cooling cycle, just as Broecker predicted.

The cooling unit is made using a cooling part of a cooling cycle which circulates a coolant between a heat-radiating part and the cooling part.

Scientists also believe it may also be possible that during the next upturn of the cycle, when solar activity increases, there might be a cooling effect at the Earth's surface.