facebook
twitter
rss
account
search
search
 

Carbon dioxide levels in atmosphere top symbolic level

May 10, 2013 at 7:21 PM   |   Comments

WASHINGTON, May 10 (UPI) -- The level of carbon dioxide in the atmosphere has surpassed 400 parts per million for the first time in human history, a U.S. climate laboratory says.

The National Oceanographic and Atmospheric Administration's authoritative Keeling lab atop the Mauna Loa volcano in Hawaii has been measuring concentrations of the greenhouse gas since 1958.

The last time CO2 was consistently above 400ppm was about 3 million to 5 million years ago, before modern humans existed, climate scientists said.

While the levels will rise and fall considerably over time periods, the long-term trend is a steady increase, they said.

"Carbon dioxide has some variability on an hourly, daily and weekly basis, so we are not comfortable calling a single number -- the lowest we will go is on a daily average, which has happened in this case," NOAA's James Butler told the BBC.

"This is the first time the daily average has passed 400ppm at Mauna Loa."

"Probably next year, or the year after that, the average yearly reading will pass 400pm," he said.

In eight or nine years, he said, "we will probably have seen the last CO2 reading under 400ppm."

Carbon dioxide in the atmosphere is chiefly a result of the burning of fossils fuels.

Topics: James Butler
© 2013 United Press International, Inc. All Rights Reserved. Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.
Recommended UPI Stories
Most Popular
1
You've got mites on your face, and so does everyone else
2
Panda fakes pregnancy to get more food [UPDATED]
3
Tech industry All Stars developing 'Star Trek'-style communication badges
4
Weird 'walking' fish holds evolutionary clues
5
Latvia boasts world's first net for migrating bats
Trending News
Video
x
Feedback