Among the extreme events, she noted record-breaking wildfires in the West in the past two years, including in Colorado, where blazes recently damaged or destroyed nearly 350 homes and killed two people.

Last spring was the warmest in the Unites States since 1895, when records were first kept. For only the third time since hurricane records started in 1851, two hurricanes formed over the North Atlantic before the season officially began June 1.

Lubchenco said that while it was impossible to attribute any single weather event to climate change, the pattern of extreme events was consistent with forecast consequences of increasing greenhouse gas emissions.

She said her agency was experiencing "skyrocketing" demand for climate change data and projections from individuals, businesses, communities and planners across the United States.