No one is asking for a magic bullet. People are asking for something better than the expensive, marginally efficient, and failure-prone compressor-based AC units that dominate the market now. There are alternatives out there that have yet to reach market-ready status, but could have a big impact - things like magnetocaloric cooling (BASF has a prototype [1]) and thermoacoustic heat engines [2], both of which have higher energy efficiency and potentially longer service life than compressor-based units.
