Environmental Engineering Reference
In-Depth Information
In the late 1970s, the global cooling trend many expected to end in disaster ended with no disaster what-
soever.
Since then, those who believe in catastrophic climate change have overwhelmingly focused on global
warming due to CO
2
emissions from fossil fuels. It has long been known that when CO
2
is added to the
atmosphere, the greenhouse effect leads to a warming impact—but before the 1970s and 1980s, there was
not much fear that it was of a significant enough magnitude to do major harm (or good, for that matter).
But starting in the 1970s and especially the 1980s, claims of runaway global warming and resulting cata-
strophic climate change became popular. How did they fare when compared to reality?
Recall that in 1986 James Hansen predicted that “if current trends are unchanged,” temperatures would
rise .5 to 1.0 degree Fahrenheit in the 1990s and 2 to 4 degrees in the first decade of the 2000s.
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Accord-
ing to Hansen's own department at NASA, from the beginning to the end of the 1990s, temperatures were
.018 degree Fahrenheit (.01 degree Celsius) higher, and from 2000 to 2010, temperatures were .27 degree
Fahrenheit (.15 degree Celsius) higher—meaning he was wrong many times over.
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Recall also that journalist Bill McKibben, summarizing the claims of Hansen and others, confidently
predicted that by now we would “burn up, to put it bluntly.”
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Looking at the actual data on a graph, it
becomes clear that he was completely wrong.
Here's a graph of the last hundred-plus years of temperature compared to the amount of CO
2
in the
atmosphere. We can see that CO
2
emissions rose rapidly, most rapidly in the last fifteen years. But there
is not nearly the warming or the pattern of warming that we have been led to expect. We can see a very
mild warming trend overall—less than 1 degree Celsius (less than 1.5 degrees Fahrenheit) over a cen-
tury—which in itself is unremarkable, given that there is always a trend one way or the other, depending
on the time scale you select. But notice that there are smaller trends of warming and cooling, signifying
that CO
2
is not a particularly powerful driver, and especially notice that the current trend is flat when it
“should be” skyrocketing.
Given how much our culture is focused on the issue of CO
2
-induced global warming, it is striking how
little warming there has been.
But most striking to me are the data on how
dangerous
the climate has become over the last few dec-
ades, during a time when all of the predictions said that the Earth would become progressively more
deadly. The key statistic here, one that is unfortunately almost never mentioned, is “climate-related
deaths.” I learned about this statistic from the work of the prolific global trends researcher Indur Goklany,
who tracks changes over time in how many people die from a climate-related cause, including droughts,
floods, storms, and extreme temperatures.
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Figure 1.8: Global Warming Since 1850—the Full Story
