Hurricane Katrina is often called a natural disaster, as if it was all nature's fault, not man's. The reality, of course, is that federal, state and local governments ignored warnings from scientists for years, both that climate change would lead to increased storm activity, and that destruction of wetlands outside of New Orleans had hurt the city's natural defenses against a storm surge. Calls for fixing levees and infrastructure investments went unheeded while the doctrine of markets and profits held sway.

This week, a federal district judge finally ruled that the Army Corps of Engineers was indeed responsible for part of the devastation in New Orleans' Lower Ninth Ward and parts of St. Bernard Parish.

The failure of the Corps to recognize the hazards wetland destruction had created was "clearly negligent on the part of the Corps," said U.S. District Judge Stanwood Duval Jr. "Furthermore, the Corps not only knew, but admitted by 1988 [the threats to human life] and yet it did not act in time to prevent the catastrophic disaster that ensued."