Charles David Keeling's measurements provided the first significant evidence of increasing atmospheric carbon dioxide concentration in the atmosphere.
A snapshot of how 2012 stacks up against the five other warmest years ever recorded in the U.S.
If it seems like autumn leaves are taking longer to change color, youÃ¢Â€Â™re not imagining things. Over the past 25 years, the onset of autumn has shifted.
As the graphic shows, people cause most wildfires. But lightning-ignited fires burn by far the most territory.
You knew it was warm last month, but today itÃ¢Â€Â™s official: it wasnÃ¢Â€Â™t just warm; it was the warmest March ever recorded in the U.S.
Online searches for the word Ã¢Â€ÂœpollenÃ¢Â€Â have gone through the roof this spring, and if you know anyone with seasonal allergies (and who doesn't?) this isnÃ¢Â€Â™t surprising.
The Lower 48 as a whole had an average shift of Ã¢Â€Âœfirst leafÃ¢Â€Â from March 20 (1951-1980 average) to March 17 now (1981-2010 average) Ã¢Â€Â“ approximately 3 days earlier.
A graphical look at the way winters have changed in the United States between 1895 and 2010.