I still can't wrap my head around the flying less thing. If I decide to not take a flight to Kona, but everyone else does, how is energy use decreased? It only works if enough people decide to stop flying such that flights are cancelled, right?

It's aggregate demand over time and over a population. You taking one less flight now won't affect anything in the short term, but over time, if you and enough people fly less, airlines will alter flight schedules or employ smaller/more efficient planes on existing routes to accommodate.

Think about it this way - say a plane has 100 seats. If you take 100 less flights over your lifetime, you've reduced demand by one whole flight. Over time, this is worked into the aggregate demand forecasts by airlines and affects the total number of flights that go out.

It's a little bit different than say, driving less, in which you make an immediate impact, but that impact is super tiny and basically a rounding error. With flying, your behavior change only works over time but is a much bigger chunk when it happens.

Right, so it's a potential savings vs. an actual savings.

I get the impact could be large, I'm just skeptical that me not taking the one flight or so I take a year would ever actually save any energy.

From 0.04% to 1% ? Surely you mean 0.1%

The "have less kids" argument is silly and doesn't take into account the marginal human capital gained from an additional person. Technology has progressed parabolically since we figured out how to grow food efficiently, generate and distribute electricity, and cure most ailments that killed people before they were 50. Every doom and gloom model assumes that we'll continue spewing carbon at our current rates and will never figure out how to sequester it efficiently. Look at the Bill Gates example - he is creating advanced solar and nuclear technology that could possibly fix everything in the next 50-100 years. Our grandchildren will probably look back at this era of panic and laugh with their abundant, cheap energy and clean air. Don't underestimate the power of the human brain.

https://www.vox.com/...nge-world-population

However, there IS one thing that you can do though in the short term - if you qualify for Kona, don't fly halfway around the world with 150 pounds of bike gear!