Personally, I happen to think global warming is a natural thing, that climate change happens in cycles (yes, perhaps influenced by technological change), but that it's nothing really new, and that it's probably a logical consequence of the existence of civilizations. As humans have done for centuries now, we try to adapt to present conditions and go on as best we can.
FWIW, it isn't the opposite in Northern states, except perhaps for arctic Alaska. Heat is always the bigger killer in a built environment, because thanks to man's ability to build dwellings and make fire and textiles, and our inability to control the weather, getting warm is relatively easy once out of the elements. Cooling down whilst still getting anything done is much harder and more expensive, technologically speaking, because the only naturally-occurring way to quickly cool a body back down to 97F when the air temp is 104F is by use of running water. Also, cold storage preserves most foods, whilst excess heat destroys them, and we need to be able to eat.
... And that brings me to why it matters. Living a technologically-advanced life in a very hot climate is more expensive and logistically complicated than it is in a very cold one, and the more people and animals who live in a hot area, the more it will need to be artificially cooled, because mammals and mechanical devices all generate additional heat. The difference in the cost structure of our lives will require some degree of change on the part of humans. (Also, I mean "cost" in the economics-study sense, both in actual money, and in decisions that may go against natural inclination, like adjusting work hours to avoid the hottest times of day.)