Internal combustion engines produce zero carbon when they burn hydrogen - which means there's a carbon-free future that doesn't involve killing the soul of the automobile. Pursuing that future in earnest could save us billions of dollars, and years of carbon emissions.
To expand, burning hydrogen produces emissions, but not substances that affect the climate or the land that depends on it.
Specifically, burning hydrogen produces NOx, an abbreviation for two different substances: NO, and NO2. These gasses are harmful to people in that they can cause respiratory issues; these are the pollutants that regulators worked to eliminate back in the '70s to improve air quality in cities. We have technologies on cars already (e.g., catalytic converters) to mitigate these emissions significantly, and tailoring combustion conditions (i.e., tuning air-fuel mixture and fuel-injection conditions) can go a long way to reducing NOx emissions from hydrogen, too. In short, NOx emissions from hydrogen combustion are, at once, a solved and solvable problem.
Importantly, neither NO nor NO2 have an insulating effect in the atmosphere; they have no effect on climate change. People often confuse these substances with "Nitrous Oxide," which actually has a chemical formula of N2O. This gas has a terrible insulating effect in the atmosphere and does contribute to climate change, but importantly, it is not produced by combustion. Instead, N2O is generally released by agricultural practices related to fertilizers.
Ultimately, we can continue to use combustion engines in a world without carbon emissions. People who like loud V8s will celebrate implicitly, but beyond user experience, this possibility has profound implications.
First, we can decarbonize any gas-powered cars relatively quickly. The shift to hydrogen largely requires a change in fuel injectors, fuel lines, fuel tanks, and ECU tuning - not wholesale package redesign. This opportunity would save the automotive industry - and transitively, customers - billions of dollars in shifting to an EV-only production base for vehicles.
Second, the industry can transition to zero carbon without abandoning the existing supply chain, or players within it. This opportunity would also save a fortune while also significantly accelerating the pace of decarbonization and mitigating geopolitical concerns associated with dependencies in the battery supply chain.
Third, the entire ecosystem of automotive use after vehicle sale can remain relatively independent and self-determined. Combustion vehicles are dependable, easy to fix, and easy to customize. While this may seem like a UX-related point, it also means that we can drive adoption faster where a vehicle architecture already has trust and understanding.
It may sound strange, but a zero-carbon future may be very loud indeed.