Global climate change, Part 2: Who or what is responsible?

In Part 1 (www.paulmarktag.com/blog/?p=391) of this two-part blog, I addressed the question of whether the climate is actually changing.  Here I will speak to the second, more contentious aspect: are human beings causing any or all of this global climate change, usually referred to as global warming?

Again, here is only a small portion of the American Meteorological Society (AMS) statement that addresses this issue. “Climate is always changing. However, many of the observed changes noted above are beyond what can be explained by the natural variability of the climate. It is clear from extensive scientific evidence that the dominant cause of the rapid change in climate of the past half century is human-induced increases in the amount of atmospheric greenhouse gases, including carbon dioxide (CO2), chlorofluorocarbons, methane, and nitrous oxide. The most important of these over the long term is CO2, whose concentration in the atmosphere is rising principally as a result of fossil-fuel combustion and deforestation.”

I believe the AMS statement, that the “dominant cause of the rapid change in climate of the past half-century is human-induced.”  Over the past decade, when I’ve been asked my opinion regarding this subject, I’ve said the following, more or less in these words. “We know that the greenhouse gasses we spew into the atmosphere are having a harmful effect on our planet. Whether these gasses are responsible for 10% or 90% of the climatic changes we are observing, it doesn’t matter. Any contribution is making things worse.”

Here is why I think what I just said is important. It wasn’t that long ago that climatologists believed that significant climatic changes occurred slowly over long periods, hundreds of years or longer. But ice cores from Greenland point to a different story from our planet’s history. It now seems that there were times when sudden, drastic changes to the climate occurred over much shorter periods, decades. If so, it means that atmospheric and oceanic processes may have a tipping point that results in sudden massive changes. Could this be going on now? My point, I think, is relevant: no matter the degree to which we are negatively affecting our atmosphere, we very much need to address our contribution. Not doing anything may have climatic implications that are just too scary to imagine.

Categorised in: White Thaw

This post was written by paulmarktag01