Am I wrong?
It is:
-cheap and easily extracted
-it leaves no radioactive wastes
-it is energy-efficient to transport
-it is mined in most places
OK, burning it produces that awful hobgoblin (CO2). But does anybody seriously believe that solar and wind will ever displace coal?
You didn’t give the full range of options and you didn’t say what you mean by “important”. Coal is already a declining energy source mainly because of the natural gas revolution that began about 5 years ago. New drilling techniques have made previously unthinkable quantities of natural gas available and we already know we have well over a 100 year supply of it in the U.S. alone. Natural gas is cleaner burning than any other fossil fuel and can do everything coal can plus more so it will continue to replace coal for large-scale uses like power plants. Coal is dirty to mine, doesn’t burn nearly as cleanly even with scrubbers and is more damaging to the environment than natural gas so there is pressure to switch from coal to natural gas.
If your question was really asking if fossil fuels in general would still be used on a wide scale in 100 years, I can’t answer that because it is too far out to make those kinds of predictions. I can say with confidence that green energy including wind, solar and hydropower aren’t capable of supplying world-wide energy needs today and will not be able to for some time. Nuclear power plants take decades to come online even if we could agree to start working on new ones now and that isn’t going to happen. Therefore, I can say with confidence that fossil fuels in general will still be a vital energy source for the next 40 - 50 at minimum because there are no replacements for it that could meet today’s demand and be scaled up to meet it any sooner than that.
Natural gas will displace coal in the United States, or at least drive the use of coal way down. That’s in the near term. In the far term, who knows?
In China and other third-world countries that desire to become first-world countries, coal will remain the fuel of choice for the near term. Hopefully they will begin switching to natural gas before too long. Nuclear should also be an option.
I would agree that coal remaining “important” is the most likely scenario. All signs seem to point to slower growth of coal power production in the near future and probably into the farther future, but power plants are expensive and long-lived assets and coal reserves are enormous and cheap to tap into. So even a diminished coal should still meet some definition of important. I’d be about 90% confident of that.
I think the only caveat I see likely is that a major revitalization of the nuclear industry could displace coal within 100 years, if that effort was driven by political/environmental restrictions against coal producers. I don’t think we could shift course that quickly in 50 years, and I don’t think market forces alone would see that change happen. But given 100 years and the right political climate, it could be possible.
I suppose it’s not impossible that nuclear fusion could even be a viable player in 100 years, but fusion seems like one of those technologies that’s always just over the horizon. It wouldn’t surprise me if our colonies on Mars were still trying to get fusion to work at scale.
Fossil fuels of all kinds will continue to be used until they are more expensive to extract energy from than the energy is worth. Oil might be going away soon, but coal will be with us for quite awhile, no matter how dirty it is.
Keep in mind though that “how much the energy is worth” depends on all the energy options available. So coal might become too expensive to mine even though it is still abundant and the technology didn’t change, simply because nuclear power got a lot cheaper. But don’t expect that to happen any time soon.
My guess is that we will use up all obtainable fossil fuels very quickly on a geological time scale. 100-200 years, tops. Welcome to the new Carboniferous era.