The Grist interviewed the Weather Channel’s “bright-eyed climate-change expert, Heidi Cullen,” whose job it is to tell Americans about the effect of global warming. She doesn’t endorse the view that global warming worsened Hurricane Katrina, but does speak of the “many human-made components to this story, especially population growth and coastal development combined with the incredible loss of wetlands, which act as a natural barrier and soak up the impact of hurricanes.” And she says, “[T]here’s plenty of compelling evidence — including a paper recently published in Nature by MIT professor Kerry Emanuel — that an increase in sea surface temperature accelerates the wind speed and precipitation levels of hurricanes. It could be that this added some fuel to the fire to help make Katrina so big and intense.”