Fossil fuels are causing global warming and threaten our planet's natural equilibrium. Air pollution caused by burning fossil fuels is bad for human health and can lead to a lot of terrible diseases. We should instead develop clean and renewable sources of energy that can make is energy independent in the future.
Suddenly going from one technology to the other is never a good idea. It took 15 years for DVDs to fully replace VHS tapes. Pulling the plug on fossil fuels and going to green energy will take time and effort to accomplish. Legislation should happen immediately, but the switchover should happen gradually to prevent any sudden price spikes to consumers. Cell phones, at one time, were expensive and only able to be owned by the rich. Now, everyone has them. The same will eventually be true of electric cars, hybrid vehicles and solar power.