Future prospects - Ice Ages and Interglacials: Measurements, Interpretation, and Models - page 329

Figure 11.5. Comparison of the global temperature anomaly (measured from space) with an
El Nin˜ o index (Douglass and Christy, 2009).

El Nin˜ o, temperatures oscillated around a new plateau about 0.3 C higher than
pre-1998.
It should be kept in mind that the climatology cabal often provides biased
public announcements regarding global warming. One minor example was in the
January 4, 2009 New York Times weather report issued by the National Weather
Service which said: ''2008 was the 36th warmest year in the US since 1895.'' But
we only exited the Little Ice Age in 1895, and the warmest years in the U. S. have
all been after 1980. Since there have only been 28 years since 1980 and the weather
report, the fact that 2008 was the ''36th warmest since 1895'' suggests that 2008
was colder than any year after 1980. But since U. S. temperatures actually
dropped from 1940 to 1980, this would further imply that 2008 was the coldest
year since 1940.
Aside from the fact that CO 2 concentrations and global temperatures have
both risen over the past 100 years or so, the principal reason many climatologists
believe that rising CO 2 has led to global warming is that global climate models
predict increased CO 2 will produce a heating effect for the Earth. There is no
doubt that atmospheric CO 2 produces a greenhouse effect by absorbing some of
the outgoing radiation emitted by the Earth. Figure 11.6 shows forcing as a
function of CO 2 concentration.
Carbon dioxide absorbs outgoing IR radiation primarily in the absorption
band between wavelengths of about 13 and 17 m. The absorption of any

wavelength in the atmosphere is dependent on the integral of absorptivity
concentration on a vertical path through the atmosphere. This integral is called
the absorption factor. Since the absolute amount of absorption depends on the
exponential function of the absorption factor, an absorption factor of 3
corresponds to about 99% complete absorption. As Figure 11.7 shows, with the

m