Greens dream of a zero-emissions world without coal, oil, and natural gas.  They need to think about what they wish for.

First, there would be no mass production of steel without coke from coking coal to remove oxygen from iron ore.  People could cut trees in forests for charcoal to produce pig iron and crude steels, but forests would soon be exhausted.  Coal saved the forests from this fate.

We could produce gold and silver without using mineral hydro-carbons, and with ingenuity, we could probably produce unrefined copper, lead, and tin and alloys like brass and bronze.  But making large quantities of nuclear fuels, cement, aluminum, refined metals, plastics, petro-chemicals, and poly pipes would be impossible.

Making wind turbines and solar panels would also be impossible without fossil fuels.  A wind turbine needs lots of steel plus concrete, carbon fiber, and glass polymers as well as many other refined metals — copper, aluminum, rare earths, zinc, and molybdenum.  Solar panels and batteries need high-purity ingredients — silicon, lead, lithium, nickel, cadmium, zinc, silver, manganese, and graphite, all hard to make in backyard charcoal-fired furnaces.  Transporting, erecting, and maintaining wind and solar farms plus their roads and transmission lines need many pieces of diesel-powered machinery.

Every machine on Earth needs hydro-carbons for engine oil, gear oil, transmission oil, brake fluid, hydraulic oil, and grease.  We could of course use oils from seals, beeswax, and whales for lubrication.  The discovery of petroleum saved the whales from this fate.

Roads would be a challenge without oil-based bitumen.  The Romans made pretty good roads out of cobblestones (this would ease unemployment).  But hard labor would not sit well with aging Baby-Boomers or electronic-era Millennials.

Cars, motor launches, airplanes, iPhones, and CAT scans would be out.  Horses, oxen, sulkies, wooden rowing boats, sailing ships, herbal medicine, and semaphore would have a huge revival.  Some wood-burning steam tractors may still work and wood-gas generators may replace gasoline in some old cars.

This is the return to the "zero-emissions" world that Green extremists have planned for us.

But modern life cannot be supported by a pre-coal and pre-oil economy.  Without reliable electricity and diesel-powered farm machinery and transport trucks, cities are unsustainable.  In Green-topia, 90% of us people will need to go.

Greens should not expect us to go quietly.