The centralized satellite and aircraft observing systems we have historically used to understand the environment are struggling to address this ‘scale gap’. Such systems are increasingly limited by their cost and complexity; society’s growing need for knowledge that spans global to local is simply outpacing the ability of centralized observing systems to accomplish this. The needs are clear: climate, energy, food supplies, transportation, nuclear proliferation, and even basic trade. But limited budgets constrain the deployment of new capabilities, so governments’ focus has shifted to making existing capabilities more efficient through international collaborations (such as GEOSS) and commercial partnerships (such as EnhancedView). The private sector has stepped up to help fill the scale gap with centralized remote sensing capabilities of its own. For example, Google Maps Street View and Bing Maps Streetside are creating rich databases of street-level imagery throughout the world. These trends will continue, but centralized systems alone cannot solve the ‘scale gap’.