Monday, September 9, 2013

Rates of Change

Noah Diffenbaugh and Christopher Field offer a sobering perspective on the ecological challenges posed by climate change in the coming decades.

In their review, "Changes in Ecologically Critical Terrestrial Climate Conditions", in the August 2, 2013 issue of Science, these two Stanford scientists suggest that the magnitude of near-future climate changes will match the greatest changes seen over the past 65 million years of Earth's history.  However, it is the rate of changes the Earth will see in coming decades that causes even more alarm.  Our planet will likely proceed along the path to these greatest climate changes at a pace 10 to 100 times faster than ever before experienced.  And if that kind of unique once-in-a-planetary-history ecological and evolutionary challenge were not enough to cause concern, today's living things, and that includes you and me and our offspring, will be trying to adapt to those rapid changes in the face of natural system habitat losses and disruption as well as pollution brought about by our own unprecedented population growth and competition for resources.

But Diffenbaugh and Field offer a sliver of hope in their final paragraph:

However, the ultimate velocity of climate change is not yet determined. Although many Earth system feedbacks are uncertain, the greatest sources of uncertainty—and greatest opportunities for modifying the trajectory of change—lie in the human dimension (emphasis added). As a result, the rate and magnitude of climate change ultimately experienced by terrestrial ecosystems will be mostly determined by the human decisions, innovations, and economic developments that will determine the pathway of greenhouse gas emissions.
In other words, what we decide to do in the next few decades will either significantly slow down or speed up the climate change we and our descendents will have to adapt to.  The speed with which we make the inevitable switch to renewable energy sources such as solar thermal, solar photovoltaic, wind, tidal, and geothermal, and leave as much coal, oil, and natural gas as we can in the ground, will mean everything to our children and grandchildren.

I have three daughters, and one of them is now expecting our first granddaughter.  I think they would expect us to make our decisions based on the best available scientific evidence unclouded by the disinformation campaign we've seen so successfully waged over the past decade.  Diffenbaugh and Field represent that best available scientific evidence.  Listen to them.  And hear your children and future children ask what you did to make the right decision today.