1. Zipline looks interesting! I've added it to my target companies.
2. I'm a vegetarian and I feel happy to see innovations like Impossible Burgers. But if I understand correctly, biochemists can contribute most to solving these challenges.
3. Do you have more resources for the third bullet? I'm apprehensive of this since some of the existential risks might be speculative and unreal.
Oh interesting I just got to know about w3w from this post. I agree with the criticisms about it not being an open standard.
But the idea sounds interesting. I won't be using it anytime soon, but I can see it can be useful to Ron Swanson who hides his gold arbitrarily under trees in forest. :)