Question: What invention does your think is most environmentally friendly?

Luke Humphrey answered on 14 Mar 2022:

For environment, the key is sustainability: inventions whose processes can continue indefinitely without fail.

This principle can apply to many things. For example, sustainable fishing requires leaving enough fish alive to reproduce at least as fast as you fish them, or the fish will go extinct and you will have no fish left. You also have fossil fuels, which use a limited resource that took billions of years to form, and will soon run out – they also release carbon into the atmosphere, which changes the environment to be one more hostile to humans. These are examples of unsustainable processes.

Thus, any sustainable invention or process is environmentally friendly, but the *most* friendly ones are those that displace/replace unsustainable inventions and processes. Renewable energy sources are the big one for me, as they’ve already started to provide a decent chunk of our growing energy needs, but we still use fossil fuels, so on their own they’re not enough. As we improve them, and improve our ability to store energy, they will continue to displace fossil fuels by providing energy sustainably. I’m focused on energy here because it really is where we have the most impact, and if we can create electricity sustainably, it’s already possible to electrify other things like transport (e.g. cars) to avoid using fossil fuels there.

However, we also need a “baseline” energy supply as well as renewables. This is because we need to create exactly the right amount of electricity that we’re using at any given time. A good example of this is that the national grid ramps up energy production during advert breaks on TV, because they whole country turns the kettle on at the same time. (This happens less nowadays with Netflix etc. but you get the idea).

This means we need a mix of energy sources including an always-on, high efficiency baseline like combustion or nuclear plus fluctuating supplies like wind and solar (it also helps to have good energy storage to give us more “wiggle room” and let us store solar energy from sunny days to use on rainy says etc.).

At my job, we’re working on fusion energy to displace fossil fuels and nuclear fission as unsustainable choices for baseline energy. So if you ask me in 2050 I will say “fusion reactors”, but for now I will say renewables. Windmills, solar cells, hydroelectric dams, geothermal generators etc.