Final answer:
Several key issues need to be addressed before hydrogen can be adopted as a global fuel, such as developing infrastructure, carbon emissions from certain production methods, potential ozone depletion concerns, storage and transportation complications, and safety hazards. Technological and economic challenges also need to be overcome to make hydrogen a viable alternative to fossil fuels and to enable controlled fusion as an energy source.
Step-by-step explanation:
Before hydrogen can be used as a fuel globally, several issues must be addressed. The current infrastructure for using hydrogen fuel is significantly undeveloped, and transitioning to hydrogen would necessitate extensive and expensive creation of facilities for the production, storage, transportation, and dispensing of the fuel. Moreover, the way hydrogen is produced has environmental implications; if derived from biomass or fossil fuels, it can generate carbon emissions. Also, there's concern about potential hydrogen leakage, which could deplete stratospheric ozone, though this requires more research.
Hydrogen gas in its standard gaseous state is voluminous, making it challenging to store, particularly for mobile applications like vehicles. Cryogenic liquid storage presents alternatives but comes with its own set of complexities. Furthermore, hydrogen poses greater explosion risks than gasoline, and the robustness and cold-weather performance of fuel cells need improvement. These technical challenges highlight why hydrogen hasn't surged forward as a primary alternative to fossil fuels.
Regarding controlled fusion technology, if made economically feasible, it could herald a paradigm shift in how energy is produced and consumed globally. The shift towards hydrogen from water as a fundamental energy source could dramatically alter the world economy and international politics, diminishing the geopolitical importance of oil and natural gas reserves. However, even as hydrogen fusion harbors the promise of a clean and nearly limitless energy supply, significant technological and economic hurdles remain.