Page 613 - 9780077418427.pdf

/Volume/201/MHDQ233/tat78194_disk1of1/0073378194/tat78194_pagefiles
tiL12214_ch23_565-596.indd Page 590 9/23/10 11:07 AM user-f465
tiL12214_ch23_565-596.indd Page 590 9/23/10 11:07 AM user-f465 /Volume/201/MHDQ233/tat78194_disk1of1/0073378194/tat78194_pagefile

People Behind the Science

Vilhelm Firman Koren Bjerknes (1862–1951)

ilhelm Bjerknes was the Norwegian sci- his coworkers to develop the highly influ-
Ventist who created modern meteorology. ential theory of polar fronts, on the basis
Bjerknes came from a talented family. of the discovery that the atmosphere is
His father was professor of mathematics at made up of discrete air masses display-
the Christiania (now Oslo) University and ing dissimilar features. Bjerknes coined
a highly influential geophysicist who clearly the word front to delineate the boundar-
shaped his son’s studies. Bjerknes held chairs ies between such air masses. One of the
at Stockholm and Leipzig before founding many contributions of the “Bergen fron-
the Bergen Geophysical Institute in 1917. tal theory” was to explain the genera-
By developing hydrodynamic models of the tion of cyclones over the Atlantic, at the
oceans and the atmosphere, Bjerknes made junction of warm and cold air wedges.
momentous contributions that transformed Bjerknes’s work gave modern meteorol-
meteorology into an accepted science. Not During World War I, Bjerknes in- ogy its theoretical tools and methods of
least, he showed how weather prediction stituted a network of weather stations investigation.
could be put on a statistical basis, depen- throughout Norway; coordination of the
dent on the use of mathematical models. findings from such stations led him and

Source: From the Hutchinson Dictionary of Scientific Biography. © Research Machines plc 2003. All Rights Reserved. Helicon Publishing is a division of Research Machines.

370
360
350
CO 2 concentration, ppm 330
340

320
310
300
290

280
1870 1890 1910 1930 1950 1970 1990
Year

FIGURE 23.36 Carbon dioxide concentration in the atmosphere since 1860, in parts per million (ppm).

of less snow in the winter or a longer summer, not necessarily
warmer temperatures. Do we have increased temperatures and Myths, Mistakes, & Misunderstandings
retreating glaciers because of increased carbon dioxide, or are these
natural variations in climate cycles that will continue to change? Worth the Effort?
The answer will not come from computer simulation of the global
The Kyoto Protocol calls for mandatory carbon dioxide reduc-
climate because the computer model will always be simpler than
tions of 30 percent from developed countries. It is a myth that
the climate itself. Scientists can only weigh the evidence and make
this would change the climate, even if followed by all partici-
a professional judgment, and this can result in disagreement. To- pants. Scientists calculated that reducing emissions as proposed
day, there is no consensus about the cause of the supposed slight would reduce the surface temperature one-twentieth of one de-
warming observed during the past 40 years. At least, the underly- gree by 2050. Human-made carbon dioxide, methane, and other
ing science of climate change should be understood. Then a critical trace gases contribute only 0.28 percent of the total greenhouse
analysis of climate change should be completed before any future effect (see Table 23.2).
policies about human-made carbon dioxide are implemented.

590 CHAPTER 23 Weather and Climate 23-26