Air conditioning. *
A temporary relief to heat, but it ends up creating more heat than it reduces.
I think a strong parallel could be drawn between the ongoing use of compressor, refrigeration-based AC and giving cigarettes to a dying patient.
Yes, some temporary relief, but...
This doesn't even take in to account that one of the worst things for our earth's upper atmosphere is a chemical used in every compressor based refrigeration unit in the US before ____ (I don't know the exact date). But this begs the question, how many countries have also banned that refrigerant? In any case, even if it's banned in all countries now, the other, above, reasons still exist.
2008-06-25 - Update. It seems some countries still haven't banned/phased out "CFCs". Just today I read that two New Zealand refrigeration engineers were prosecuted and convicted of "depleting the ozone layer".
According to the news story, HCFCs are banned under an international agreement starting in 2015.
* Refrigeration based "AC" that runs off a compressor.
Evaporation based AC uses SIGNIFICANTLY less electricity. However, evaporative cooling, as awesome as it is for many reasons and in many places, doesn't work in areas where it's humid.