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WE ARE THE CAUSE
OF GLOBAL WARMING
CHARLES KEELING (1928–2005)
IN CONTEXT
BRANCH
MeteorologyBEFORE
1824 Joseph Fourier suggests
that Earth’s atmosphere makes
the planet warmer.1859 Irish physicist John
Tyndall proves that carbon
dioxide (CO 2 ), water vapor,
and ozone trap heat in
Earth’s atmosphere.1903 Swedish chemist Svante
Arrhenius suggests that the
CO 2 released by burning
fossil fuel might be causing
atmospheric warming.1938 British engineer
Guy Callendar reports that
Earth’s average temperature
increased by 1°F (0.5°C)
between 1890 and 1935.AFTER
1988 The Intergovernmental
Panel on Climate Change
(IPCC) is set up to assess
scientific research and
guide global policy.T
he realization that carbon
dioxide (CO 2 ) levels in
the atmosphere are not
only rising but might also cause
disastrous warming first came
to widespread scientific and
public attention in the 1950s.
Past scientists had assumed that
the concentration of CO 2 in the
atmosphere varied from time to
time, but was always around
0.03 percent, or 300 parts per
million (ppm). In 1958, American
geochemist Charles Keeling began
to measure the concentration of
CO 2 using a sensitive instrument
he had developed. It was his
findings that alerted the world
to the relentless rise of CO 2 and,
by the late 1970s, to the human
role in accelerating the so-called
greenhouse effect.Regular measurements
Keeling measured CO 2 in several
places: Big Sur in California, the
Olympic peninsula in Washington
State, and the high mountain
forests of Arizona. He also recorded
measurements at the South Pole
and from aircraft. In 1957, Keeling
founded a meteorological station at
10,000 ft (3,000 m) above sea level
on the top of Mauna Loa in Hawaii.Earth’s temperature
is rising.Carbon dioxide
is a greenhouse gas
that traps heat in
Earth’s atmosphere.Its concentration in the
air is rising in line with
fossil fuel consumption.We are the
cause of global
warming.