Cornell is currently leading an NSF Expeditions in Computing project titled Computational Sustainability. The NSF also funded three other such projects, which are described in their announcement.
In a nutshell, computational sustainability is about developing techniques to formulate and solve large scale problems which mix together environmental, economic and societal needs both for the present and the future. Both the NSF and members of the project hope to create a new interdisciplinary field in a manner analogous to computational biology.
As the computer science field matures, various sub-areas will likely spin off into their own fields (something I've pondered about before). Some sub-areas will join forces with sub-areas from other fields. Cornell is currently home to a department of biological statistics and computational biology, which mixes together (not surprisingly) relevant areas of biology, statistics and computer science.
As I see it, the creation of these fields is important for two main reasons. First, it bridges the communication gap between different fields. While attending the kick-off meeting for the Institute for Computational Sustainability, I was surprised by the lack of awareness even here at Cornell. Researchers from many other fields were seeking answers to problems that computer scientists have already contemplated (at least in some idealized setting).
These institutions are also particularly important for enabling disciplines such as computer science. I've seen enough assistant professors be denied tenure because their research was deemed to have insufficient fundamental impact within computer science. We must have a system that recognizes the scientific value of their work.