alt Hacker NewsI haven't had time to watch the video but my understanding was a lot of the Louisiana coast have big problems with rising sea levels and much of it in the process of falling underwater. Perhaps it's relatively trivial to reinforce the coast for the forseeable I don't know.
The plans for the site involve extracting significant amounts of natural gas to make methane to burn for the rocket fuel. If they hit the launch levels they suggest (thousands of launches per year), this is not a small amount of greenhouse gases they'll be emitting which of course helps accelerate melting of the ice caps and rising sea levels, which could threaten the very site they've built it on.
They're also the folks working on the largest co2 -> methane converters in the world. Because that's how they'll need to make fuel on Mars, and no one else on earth wants to fund an expensive technology to replace an inexpensive gas pumped from the ground. By definition, these reactors will have to be capable of producing enough fuel for a rocket in order to be fit for purpose. That opens the door for carbon neutral operation. It's tough to imagine a greener rocket than a fully reusable one that's carbon neutral running on methane. Sure beats spewing hypergolics or solid rocket fuels.