When I say these people deserve compensation, what I mean to say is that they deserve to live just as well as those who are unaffected by climate change. And they also deserve to live in a world where they don't have to worry about nonsense like climate change worry.
It is unfortunate, that there are those, suffering from recent climate changes, but those who depend on certain weather conditions, such as those in the agriculture industry, are educated by neighboring farmers, ranchers, or their local Farm Service Agency about how to prepare, for the worst. Crop failure, because of catastrophic weather conditions, is an event that wise farmers prepare for, by purchasing an insurance policy, as a safety net, should disaster strike. This is similar to any business owner, taking out a policy on their business structure. If warnings aren't heeded by the affected party, who can they ask, for compensation, when they simply felt that preparing for the worst was an unneccesary inconvenience.
We don't know for sure what is causing climate change, so it would be impossible for someone to know who to go after or press charges against. For example, let's say a farmer blames climate change on having a bad harvest season. Who would he or she go after to seek compensation for this problem? It would be impossible to prove in court, even if the farmer really did blame a specific person or company.
It would be ridiculous to believe that you are entitled to compensation because of climate change. There is not hard evidence to suggest that it is caused by people, and not by natural climate cycles of the Earth. It is not anyone's fault that the Earth does what it naturally does. Demanding compensation is outrageous.
It is not reasonable for those affected by climate change to demand compensation. I do not see who those affected by climate change would demand compensation from, but any governmental entity is a non starter. It is completely unfair to ask those who have not been affected by climate change to pay for those who have. Furthermore, it is literally impossible to claim such an effect, since climate change occurs over millenia, not over the course of an individual person's life.