Friday, October 1, 2010

GHC10: Computational Sustainability: Computational Methods for a Sustainable Environment, Economy and Society, Carla P. Gomes

Professor Carla P Gomes, faculty of Computing and Information Science and director of Institute for Computational Sustainability, is a pioneer in the field of computational sustainability.

In 1987, there was a UN report that first raised concerns about human impact on the planet. A follow-up report showed things like the biomass of fish is 10% of what it was 50 years ago.  We're over harvesting our planet and overusing our resources.  A 2009 report looked at whether or not we've crossed the tipping point, and it was looking grim. All these things inspired Professor Gomes to do further research in this area to see what we could do to help reverse the tide using the field of computer science. She strongly believes that computer scientists can, and should, play a key role in increasing our efficiency of managing natural resources.

Computational sustainability encompasses many disciplines like economics, sociology, environmental sciences and engineering, biology, crop and soil science, meteorology and atmospheric science.  There is a need to develop computation methods to model things in these fields, which will help resolve these problems.  This cross discipline model helps all fields learn new research models from each other, which is helping things in this area to progress.

One problem this field is addressing is wildlife corridors, which link biological areas allowing animal movement between areas. One of the issues here is that, while important for the the animals, there isn't usually much money available to buy land, etc, to set these corridors up so that animals in different national preserves can cross populate.  This is a computational problem - need to find the graph that has the best and cheapest path between the two places. While this is an NP hard problem, the computer scientists can simplify the problem by using the Min Cost Steiner Tree. Models are critically important in solving these problems and for addressing the issues of scale.

This approach allows them to handle large problems and reduce corridor cost dramatically, allowing the projects to actually proceed as opposed to being ignored or done with too much expense or in a sub-par fashion that won't help the animals as much as possible. Her work has been done for grizzly bears and wolverines.

Now she is working on assisting the recovery of a subspecies of woodpecker, by analyzing network cascades. They are buying up the land where the birds fly, then looking at the birds flight patterns and buying nearby land, which will help the birds spread their territory which will lead to increased population. The complicated issue is figuring out which land the birds will choose to spread to.

Further consideration is necessary for species interaction, as not all species interact in a cooperative manner.

They are getting help from the eBird project, at Cornell, which allows average folks to submit data about bird sightings. This helps them to learn where the birds are migrating and how long they spend in various areas.

Many of these concepts can also be applied to analyzing solutions to problems fought by very impoverished communities. For example, what will be more valuable to the impoverished? A chicken, improved roadways, or providing cell phones?

Back to the problem of over fishing, it seems to be caused by mismanagement. Professor Gomes is looking at models to help correct this mismanagement without causing any additional problems. Even after they figure out recommendations they need to get the fisheries to implement them. It is difficult to convince fishery owners that periodically closing the fisheries will actually lead to more fish when they reopen - you gotta give them time to reproduce and reach reproductive age!

Another thing her team is studying is the impact of fertilizers. While they do greatly increase the amount of food that can be harvested, they end up creating dead zones. On top of all that, they are also studying how to discover materials for fuel cell technology! These, again, Professor Gomes claims are problems for computer scientists.

Professor Gomes's research area is so incredibly broad! She shared with us, more quickly than I could capture, many of the different algorithms and approaches they are using to solve these problems. I got a great mini-introduction to all sorts of algorithms and data structures I'd never heard of before, like a spatially balanced Latin squares! She is an amazingly energetic, intelligent and passionate technical speaker and I think I could spend an entire day listening to her!