The claims it isn’t possible to replace all fossil fuels or that it would create too much economic hardship are nonsense, we’ve had the means to replace fossil fuels for decades and the ability to create a much more robust and sustainable global economy and society.
Since the mid 1960s there has been nuclear power technology that is far superior to “conventional” pressurized and boiling water reactors which require solid fuel assemblies and high pressure in the reactor vessel to allow the high water temperatures needed to transfer enough heat to generate electricity with steam turbines.
Molten salt reactors have the fissile fuel in solution in high temperature salt, which means that no pressurization of the reactor vessel is needed and there is no solid core at risk of meltdown. The core is already in a molten state. One of the limiting factors in current nuclear power is the amount of waste produced. Because solid fuel assemblies rapidly degrade due to heat and neutron bombardment and the build-up of fission products that impeded the stable running of the reaction process, they must be replaced about every 2 years years. This allows only about 0.7% of the available fuel to be burned up. With a single stage liquid fluoride thorium reactor fuel efficiency is about 50% and with a two stage LFTR the fuel efficiency approaches 100%. The waste stream from a LFTR is much less and as it is almost completely fission products with much shorter half lives it has mostly decayed to inert ground state within a decade with most of the longer lived radioacative isotopes stable in about 300 years. Much less waste, needed to be stored much less time. And much of the material coming out of a LFTR is commercially valuable like;
Bismuth 213
Targeted alpha therapy is an example of a technology that is used to kill dispersed cancers such as leukemia and lymphoma. A radioisotope that undergoes alpha decay is chemically bonded to an antibody and injected into the body. The antibody seeks out and binds to the desired cell, then after a certain time period, the attached radioisotope decays and the alpha particle emitted during the decay kills the targeted cell. Targeted alpha therapy has shown great promise but has been strongly limited by the supply of suitable radioisotopes. The most promising is bismuth-213, which has a half-life of 45 minutes and is formed from the decay of uranium-233.Technetium-99m
Technetium-99m is an example of a radioisotope used for the detection of various medical conditions. Tc-99m is chemically bonded to a variety of different agents that target specific areas of the body, such as the heart, bones, liver, or gall bladder. As it undergoes radioactive decay, Tc-99m emits a high-energy photon of light, called a gamma ray, that can be detected by an external camera. This procedure, called single-photon emission computerized tomography (SPECT) allows doctors to image areas of concern within the body. Tc-99m has a half-life of only six hours, and is formed by the decay of molybdenum-99, which in turn is formed in a nuclear reactor from the fission of uranium. The medical molybdenum market accounts for the vast majority of yearly radiopharmaceutical use, approximately 30 million procedures a year, and is currently threatened by supply contractions.http://liquidfluoridethoriumreactor.glerner.com/2012-useful-lftr-fission-by-products/
Fission of 1000 kg U-233 produces several chemicals essential for industry, readily extracted from a LFTR or any other Molten Salt Reactor, including 150kg xenon, 125kg neodymium (high-strength magnets), 20kg medical molybdenum-99, 20kg radiostrontium, zirconium, rhodium, ruthenium, and palladium. MSRs also produce non-fissile Pu-238, that conventional reactors can’t produce isolated from highly fissile Plutonium-239; Pu-238 is needed for radioisotope power such as for NASA deep space exploration vehicles (none left, only Th to U-233 makes Pu-238 w/o Pu-239).That's before we even get to solar, wind, tidal, geothermal and biomass power technology which is rapidly advancing as is the technology to store the power generated. As far as internal engine technology that utilizes fossil fuels there are a number of technologies that do not add to the carbon dioxide concentration of the atmosphere making the climate change catastrophe worse. Those include catalytic processes like thermal deploymerization which take any materials with long chain carbon molecules and using heat and pressure convert them to short chain carbon molecule similar to light crude suitable for refining. The feedstock can include wood waste, animal products, rubber, and even human sewage. https://en.wikipedia.org/wiki/Thermal_depolymerization There are also processes that can produce synthetic diesel fuel from air using electricity and carbon. https://en.wikipedia.org/wiki/E-diesel Electric car technology is also advancing rapidly. So tell me why we are doing suicidal things like continuing to invest in decades more of totally unsustainable and highly destructive projects like the tar sands. Our PM here claims we need to extract and burn all the 170 BILLION barrels of tar sands bitumen even though it's one of the most polluting sources of energy on the planet as is gas fracking when the methane leakage is included. The BC government intends to make gas fracking and LNG production the cornerstone of our economy here for decades. Then we get to the US where the entire executive branch of the US government can be considered an enemy of the people by making climate change denial a central part of its policy. We could have sustainable advanced technology as the basis for our societies and economies probably resulting in a revolution in how we live giving us real shot at a future that would likely include much greater space exploration and colonization without destroying the Earth. Those same LFTRs are fully compatible with being used on a Moon or Mars colony and some of the material they produce is used as fuel by high efficiency ion rocket motors by the aerospace sector. We could have a much better future without fossil fuels and we could begin to replace them all today. Instead we're looking at no future at all because just a few of us demand we keep burning fossil fuels that are already causing catastrophe.