What we are experiencing is climate change, with the overall trend to warming.
Imagine the planet is like a swimming pool with a large chunk of ice at two ends, and heat lamps at the middle ends, (it's a round pool), with a current which swirls the water around. The ambient room temperature is such that, with only minor fluctuations, the overall system stays constant. Water is cooled at one end, drifts towards a warm end where it is heated up, then drifts towards a cold end where it cools down again and repeats the cycle again and again.
Now what happens if the room temperature, which in this case serves as the metaphor for greenhouse gasses heating the atmosphere, is heated up. The ice melts. Now, if you are on a landmass nearer the ice, you will experience colder temperatures, as the water is being cooled by the melting ice. Other parts of the pool will experience hotter temperatures than normal. The water currents which are formed by the fluctuations in the water temperature begin to change, becoming stronger in some areas and weaker in others, which in turn affects the wind patterns, causing further climate change.
The result is, that while we may be feeling cooler than normal temperatures in some parts of the world, the planet as a whole is warming up.
Now here's the kicker... global warming could, in theory, actually bring on an ice age. If enough ice melts due to global warming, the oceans could become super cooled, if this happens too much, the water currents won't be able carry enough warm water from the equator to the far northern and southern poles, resulting in drastic cooling.
The key word here is climate change. Whether you believe it is natural or man made, I think human beings should be making every effort to not upset the balance further.
