While some claim there is insufficient
documented evidence proving that anthropogenic effects are the driving force
behind climate change, the opposite is true. There are many published studies
that show not only that climate change is occurring, but that anthropogenic
effects are the only consistent driving factor behind climate change.
This image shows past, present, and
future predictions of global surface temperatures. It also shows the four main
forcings scientists associate with climate change. Many climate change
naysayers blame what is occurring with our Earth on three of the four forcings.
What is incorrect about their argument is that when one compares the three
natural forcings and anthropogenic effects to global surface temperatures, the
only correlation one can see is the one between increasing anthropogenic
influence and increasing global surface temperatures.
The first forcing is El Nino
Southern Oscillation (ENSO). This is a cyclical pattern that occurs in the
Pacific Ocean, which has profound effects on climate when it occurs. The
cyclical nature of ENSO tends to increase and decrease climate temperatures;
however, the effects are never permanent and the climate tends to return to a
homeostatic condition, with respect to ENSO effects. Also, one can observe
matching increases and decreases in temperature in both the ENSO graph and the
overall global surface temperature graph. However, the aforementioned trend
does not increase exponentially and typically returns to normal.
The second forcing is volcanic
aerosols. Many believe that volcanic eruptions are the sole cause of climate
change because they spew large quantities of ash and gas into the atmosphere.
While it is true that large quantities of ash and gas enter the atmosphere and
volcanic events further exacerbate the problem, they are not the sole cause of
a constant exponential increase in climate change. Looking at the graph, one
can see large volcanic events noted on both the volcanic aerosols graph as well
as the global surface temperature graph. Overlaying the two, one would note
that the events match up in both date and effect. However, as was the problem
with ENSO, volcanic aerosols only affect the environment for a couple of years
before the effects wear off. It does not account for the increasing trend of
global surface temperatures.
The last natural forcing which
scientists have studied in depth is solar irradiance. Many claim that recent
sun spot cycles, in addition to other solar events, are the cause of the
increase in global surface temperatures. Again, these events are cyclical in
nature. Scientists have been able to obtain data and graph the cycles and their
increases and decreases in temperature. Looking at the graph, one can see these
warming and cooling trends. Again, overlaying the solar irradiance graph and
global surface temperature graph, one can see the cyclical nature of solar
irradiance reflected in an increase and decrease in global surface
temperatures. However, as was the case for each of the forcings above, these
effects are not permanent and they eventually return to normal.
One of the many problems with the
hypothesis that natural forces are responsible for climate change is that Earth
was built to withstand these changes. These three natural forces are not new to
Earth as a planet. These cyclical changes have occurred since before mankind
was able to measure their effects. The one forcing that the Earth has not dealt
with until now is that of anthropogenic effects. The Earth was not built to
withstand such effects.
Looking at anthropogenic effects, the
last forcing graphed, one sees that this is the only force which is increasing
exponentially. Overlaying the two graphs we notice that anthropogenic effects
are increasing exponentially at the same rate global surface temperatures are. While
some may say that not enough climate history is known to definitively say that
humans are the driving force behind climate change, scientists know this to be
erroneous. Yes, Earth as an entity goes through cyclical warming and cooling
phases; however, anthropogenic effects were never a factor prior to the
Industrial Revolution. Therefore, while the Earth does go through cyclical
patterns, this is not what we are currently seeing. Never before have we seen
an exponential growth in global surface temperatures until the post-industrial
revolution era. Anthropogenic effects provide the only correlation between
increased warming and the four forcings.