I wrote a blog post on applying Effective Altruism to climate change. I used information from Drawdown.org as well as my own analysis. The results show that many solutions that are often promoted like high-speed trains, electric vehicles, green roofs and others are actually very high-cost relative to their CO2 reduction. Less known solutions like silvopasture, restoring tropical forests, and managing food waste are actually much more cost effective per gigaton of CO2 abatement.
You can read the full blog here: https://medium.com/@tsloane/applying-effective-altruism-to-climate-change-e2d703f6414f
I'm curious to get your thoughts on approach and results.
"I wonder where most of the waste happens?"
Most of the business-driven elements of the food supply chain are quite efficient, I'm told. I.e. each of manufacture, transport, and retail management. The waste comes almost entirely from customers buying things they don't need and then throwing them away.
If so, the most likely downside, if any, is the risk of people consuming food after its use-by date.
My source for this claim is a pitch from a food-waste charity. I consider this to be a slightly better source than a person chosen at random, however I didn't get the impression that the charity was rigorous about fact-checking its claims, so I can't promise this is correct.