NCA Backgrounder and Talking Points

The Third National Climate Assessment (NCA) was released on May 6, 2014 by the White House. The assessment documents how climate change impacts regions and sectors across the United States, and how society is responding to climate change.

Tracking Climate Change

Tracking Climate Change

In a stable climate, the ratio of new record highs to new record lows is approximately even. However in our warming climate, record highs have begun to outpace record lows, with the imbalance growing for the past three decades. This trend is one of the clearest signals of climate change that we experience directly.

Finger and hand fingerprints in William James Herschel's Beginnings of Fingerprinting. Forcing and Fingerprinting

Forcing and Fingerprinting

The IPCC recently concluded (with 95% certainty) that humans are responsible for over half of the warming we’ve experienced since 1951. Their best estimate is that we’re responsible for all of the warming, and we could even be responsible for …
Dr. Mike Mann on Climate Models, in office with books in the background

Dr. Mike Mann on Climate Models

Noted climate scientist Michael Mann discusses the scary reality that human greenhouse gas emissions are currently overcoming natural forcings, as well as the current confusion around surface warming, climate models, and natural variability.

Photo of the frozen Schuylkill River, with the city of Philadelphia in the background. (Polar Vortex)

Polar Vortex

Right now, the eastern United States is seeing a cold snap, which could cause some to wonder whether the world is still warming