By technological fixes in agriculture, I simply mean greenhouses and fertigation systems. Control the environment in which plants grow more closely and thereby mitigate risks associated with weather shock. Works great for things like capsicum, high value lettuce etc. I don't see how this can be replicated for things like wheat and maize, although admittedly GM crops potentially offer some route to solving this problem.

For wheat and maize it can't and it doesn't have to. Both are stable after picking and can be transported. Lettuce cannot be transported as well after being picked. Maybe shipping containers with live lettuce?

Re wheat and maize, it's what happens before they're picked that is the concern. Where banks project high rates of loss, they simply withdraw from the sector - understandably.

Re lettuce, I think what we will see is 2 things: firstly highly capitalised vertical farms close to where the lettuce will be consumed. Secondly, smallscale contract farming again close to point of consumption. Imagine a small greenhouse in your back garden. You pay for the infrastructure and have Uber like aggregator linking you directly to buyers. Oh god - I can see the pitch now: it's like Uber for Romain lettuce...

The problem with Uber for romaine is that it takes at least a month to fill the demand for romaine. Anyone with a car could, potentially, sign up and fill a ride request. In practice, this might not be a big problem if the shortage is longer than the time it takes to grow romaine. This is where my mind was going with this but it would require people to have equipment sitting idle or be growing romaine lettuce anyways and sell it when the price is high enough.