I seem to remember this question in school, about 40 years ago!
Our continued access to fossil fuels comes at a price, though. The easily accessed oil and gas are largely depleted. It's been advances in technology like offshore drilling and fracking that are keeping the cars on the road today -- and these carry a much greater environmental risk than a well in a Texas field.
There is a good reason 'alternatives' are still 'alternatives' after so long and so many billions of $ thrown at them. If they were ever viable they would have ceased to be 'alternatives' long ago.
But they have
become viable. Like an energy Moore's law, prices of wind and solar have plummeted, while efficiency has soared, and the trend continues. In many regions "alternatives" are already equal to or cheaper than fossil fuels.
Fossil fuels revolutionized industry, transport, farming, and standards of living worldwide, practically overnight without a penny in handouts- that's what a promising new technology looks like- and the viability gap between this and 'alternatives' has only grown ever since.
No, the "viability gap" is shrinking, and no matter how much support the energy conglomerates can buy from congress, it will soon reverse. The invisible hand of the market will doom the industry.
Can alternative energy effectively replace fossil fuels?
Yes, as soon as people can figure out how to make it happen.
Don't we already know how to make it happen?
Walk or ride bikes or horses?
Aren't hybrids and electric vehicles already one of the hottest divisions in the industry? Soon 200 mile-per-charge cars and motorcycles will be common.
If it were really all that cost effective, power companies would be replacing
their old plants with solar cells. But we only see small demonstration
projects to curry favor with greenies. I hope that changes though.
The advantage of fossil fuel plants is that they are concentrated, point sources. Profits can be concentrated in the hands of a few industrialists.
Profits from wind and solar are a lot more difficult to consolidate, as generation is spread out among many individual sources.
European countries moving to electruc vehicles:
Electric cars win? Britain to ban new petrol and diesel cars from 2040