The current methods are not working and we need a viable alternative.

Without water and sunlight, the plants are not viable.

Vitamins are not a viable alternative to poverty induced clinical malnutrition

Yes, vocational school is a viable alternative for students who are having trouble with academics. One can get many jobs based on skills learned in vocational school.

There is nothing whatsoever to stop you from using what ever in your jugement is a viable alternative pool sanitizing system.

Because to date there is no viable alternative to fossil fuels, that are plentiful and cost effective.