Currently much of the big data being churned out is merely exhaust. But imagine the possibilities once we figure out how to produce and process better data on the fly on a global scale. Call it Big Inference.
I'm thinking Gaia's brain: distributed but unified intelligences that gather data from sensors all over the world, and that synthesize those data streams to perceive the overall state of the planet as naturally as we perceive with our own sensory systems.
We need to gather the data. We need the processing power to interpret the data. We need the algorithms. To actually make sense of the data and decide what actions and responses to take, we have to figure out how to extract high-level patterns and concepts from the raw inputs. There is an ongoing debate over the right approach.