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(Image Source: NOAA)
BY SCOTT MALONE
Earth's atmosphere is entering an era
that hasn't been seen for millions of years, and the scientific community is worried. Scientists
in Hawaii announced Friday the level of carbon dioxide in the air has reached 400 parts per
million for the first time in a very long time.
For millions of years CO2 levels stayed below 300 parts per million, but that changed after
the industrial revolution — when we began burning coal, oil and gas, which releases
CO2 into the atmosphere. (Via Al Jazeera)
Several members of the scientific community call the 400 parts per million level a milestone,
because "It gives us a chance to mark the ongoing increase in [carbon dioxide] concentration
and talk about why it's a problem for the climate." (Via The Washington Post)
Scientists say CO2 is a problem for the climate because it's a greenhouse gas that's efficient
at trapping heat from the sun — even if it makes up just .04 percent of our atmosphere.
One scientist said at this rate, "In eight to nine years we will probably have seen the
last CO2 reading under 400ppm." (Via BBC)
So a milestone today could become the norm in the next decade. An environmental analyst
told the BBC despite the best efforts of governments around the world, they're finding it tough
to cut back on CO2.
"In theory, we have not given up on reversing CO2 emissions ... In practice, they have been
promising all sorts of action now for many years, and they're finding it very difficult
to deliver."
Just how difficult has it been? Last year, global carbon dioxide emissions soared to
a record high of almost 36 billion tons.
But a writer for The New York Times notes "many countries, including China and the United
States, have refused to adopt binding national [emissions] targets."
Then again, if less than one percent of our atmosphere is composed of CO2 it shouldn't
have that large of an effect, right?
A writer for LiveScience says think again. The last time carbon dioxide levels were this
high — three to five million years ago — global temperatures were between five and seven degrees
higher, and sea level was as much as 131 feet higher in some places.