That's the problem with "Ltd" companies and long-term investments/liabilities.
Worst case, Thames Water goes for bankruptcy, oops.
The point is, as long a company has assets had might need "finalisation" (aka clean up) or "maintenance", paying out profits becomes a game of faith.
Or as our neoliberal/libertarian friends like to argue, you don't have to take costs for climate disruption into account, because a magic technology is just around the corner that will fix it for free.