Alternate Histories (Hypothetical Historical Scenarios): What would the world look like today if fossil fuels never existed?

Just as need Is the mother of invention. Availability is it's guide...

The loss of coal would be the bigger blow, since that would hurt not just industries reliant on steam power but also steel production. It's still possible that we would see industrialization, but it would be heavily dependent on wood fuel (and would likely foster a massive world trade in wood for fuel in factories). If said hypothetical civilization discovered how to utilize electrical power, then a number of options open up for them (including hydroelectric power). Oil would not be so significant a blow (although it would constrain the energy resources of our hypothetical civilization). We would likely see a continued reliance of rail travel and transport, with a significantly earlier mass electrification to supply and run it. It would eventually be possible to run cars off of synthetic coal-gas (as well as natural gas), but that would come much later than it did in our real history.

A lot less developed, a lot less populated, a lot less economically integrated, a lot poorer, and a lot uglier of a place to live; in short, it would look much as it did before the industrial revolution. Access to cheap, abundant fuels has revolutionized our way of life and allowed many of us (and certainly those sitting there reading this response) to live lives of comfort beyond the wildest dreams of pre-industrial kings. Edit: The modified question asks whether modern accomplishments would have been possible without fossil fuels. I don't think so. While it is possible to create biofuels from algae, and ethanol from corn, neither of these have the incredible bang-for-the-buck that light, sweet, crude does, and neither can conceivably produce transportation fuel in the amounts required to sustain modern civilization. As for electricity, the only non-fossil fuel source worth considering is nuclear power. It is the only green electricity source that can provide base-load electricity generation, as it can maintain a constant output for years at a time. Wind and solar power are too intermittent and fluctuating to be at the core of any electric grid. This is all assuming we could even develop these technologies in any reasonable time in the absence of fossil fuels. While there is no direct need for fossil fuels to spur research and development, they are largely responsible for the scientific advancements we have had in the past two centuries due to the enormous wealth they have added to our economies, allowing us to pour huge sums into R&D. I would give a resounding "no" to the question of whether or not we could support a world even remotely similar to our own without fossil fuels.

It seems likely that civilization would repeatedly advance and collapse at the "whoops we chopped all our trees down" stage. There are a few examples to support this. Deforestation to plant cropland and produce mortar for pyramids was arguably a major contributor to the collapse of the Mayan civilization. In the UK, the enormous consumption of wood for heating, cooking, and producing charcoal was entirely unsustainable until coal exploitation grew rapidly to relieve pressure on forests. High-density, carbonaceous energy sources are simply critical to industrialization. Steel-making, railroad travel, urban heating/cooking, and synthetic chemistry are all heavily dependent on large supplies high-quality combustibles. Yes, a combination of hydropower and charcoal can meet these needs, but those energy sources are difficult to scale. Large dams are difficult to construct without a large industrial base for production of steel and cement, as well as fossil-fuel powered construction machinery. And the amount of fuel firewood required to produce charcoal by traditional methods is entirely wasteful. Pre-industrial non-fossil power sources simply do not scale well. Relying on biomass for energy must critically link the maximum industrial intensity and population density to the availability of forest land. Basically, humanity's potential would be limited by the rate we can grow and chop down trees. That's not a good place to be stuck. Vaclav Smil's Energy Transitions is a great book on this subject for those interested in learning more.

Remember, the industrial revolution started with water-powered mills.  So not only could industrialization have been possible without fossil fuels, it actually was.

Alcohol makes a very good high energy density fuel, and vegetable oil can be utilised in a diesel engines, so the invention of the internal combustion engine of either type would not have been hindered, Producing alcohol or vegetable oil in the same quantity as we now use gasoline would have been a definite restriction. Solar recharged battery based electrical propulsion would also be developed sooner since that also does not require fossil fuels. Wind power and water power both were in heavy use back in the pre industrial days so would have carried on being developed. Imagining society back then without coal and oil reminds me of what we are trying work towards in the here and now in anticipation of fossil fuels running out. Early industry was kick started using wood and charcoal the utilisation of coal and then oil simply provided an acceleration.

An interesting question. When you say "fossil fuels", I'm going to pretend that includes all carbon based sources, an even more restrictive viewpoint, and assume (unlike other postings here) that alcohol and wood cannot be used (they are, after all, just short-term solar power storage systems, as coal and oil are long-term storage). So getting to the meat of it; "In 1897, http://en.wikipedia.org/wiki/Frank_Shuman, a U.S. inventor, engineer and solar energy pioneer built a small demonstration solar engine that worked by reflecting solar energy onto square boxes filled with ether, which has a lower boiling point than water, and were fitted internally with black pipes which in turn powered a steam engine." This, I think, would have been the beginning of the solar power industrial engine, though I think it would have gathered steam (pun intended) slower than a coal or oil based system might. For one, we would have created an industrial engine that would have functioned best during daylight hours, seriously slowing down during the winter. Our economy and energy usage would be wrapped around being able to store heat at night. There would have been massive pressure to create better thermal storage devices, and to store electricity. Note that electricity would primarily have been produced during the day at first, but thermal storage (molten salt) that we're only now refining would have been highly developed by the 1920's or 30's to provide for nighttime electricity and heat. Silicon cells and computers may have been delayed by 10-20 years, though electricity obviously would have been available about the same timeframe as it was historically using Shuman's solar steam engine. I've left a big part out; refining metals so you could actually make a solar reflector and use that heat to refine metals for engines. But then, glass lenses were being used in the 1700's, and if there were no other source for concentrated heat, then this would have been developed before parabolic reflectors; Fresnel lenses were around during Fresnel's life (1788-1827), so that might have gotten the industrial revolution off to a start. I could easily imagine a smelting operation based on a building-sized Fresnel lens. There's also no reason that plastics wouldn't be developed, and plastic parabolic reflectors would shortly follow. Many of the delays in solar development (like thermal storage and batteries) have been because of the easy availability of portable, storable, high energy density, liquid fuels - there was just no profit in it, so the technology to bring production costs down to oil/coal levels had a long uphill battle, primarily being developed in very limited applications where oil wouldn't work (like satellites). I think the pressure to develop solar/wind systems and energy storage would have been much higher without oil and coal to provide the energy, so that might have accelerated the industrial revolution. We've been using coal for thousands of years. It's like the difference between creative pressures on hunter/gatherers in an environment where there's plenty of food (no pressure) and the pressure to invent in an area that's cold and has little for (extremely high). The ease of availability of coal and oil may have set the industrial revolution back by hundreds of years; hard to speculate. It's not intuitively obvious. Another way to look at the question is; if an alien civilization were to evolve underwater, could they ever develop an industrial civilization, since they couldn't burn anything? Great subject for SF to explore.

Rathermore slowly.  But there was little use of fossil fuel before the 18th century.  Charcoal can do most of the same jobs, along with wind power and water power.   We'd not have anything like so many private automobiles.  The petrol engine won out because it is so convenient.   This would also mean a much slower development of climate change, though lots of other processes contribute.