Talk of the Town: Examples of climate-change severity
A recent letter to the editor of The Daily Courier (Oct. 11) doubted the severity of our current climate change. It is easy to imagine that a warming of 2 degrees F will be bearable. But as a student of consequent sea-level change, I would like to present that as an example of climate-change severity. There are no doubters about this.
Melting glaciers and thermal expansion of sea water are causing sea level to rise at the fastest rates since the biggest ice sheets finished melting 10,000 years ago – when the only human observers were still in the Stone Age. Due to lags in the system, seas will continue to rise for over a century even if we deal with greenhouse gases immediately.
We in Prescott don’t have to fear inundation by rising seas, of course, though I imagine that many of us have friends and relatives who do. In coastal plains of the eastern US, for example, the rate of sea-level rise is several millimeters per year, which translates to encroachment of salt waters inland of several meters per year, forming “ghost forests” along coastal river margins, as far inland as Philadelphia, Richmond, and Houston. Meanwhile, barrier islands from New Jersey to Texas will roll landward grain by grain, adjusting to the new hydrologic situation, leaving resorts behind in the surf. And, of course, we’ve all read what is happening where cities like Miami are sited on beaches separating swampy land from the sea.
Few coasts anywhere will escape revision. Our cliffy West Coast, for example, would appear to be immune, but sea-cliff erosion of softer rocks will accelerate, especially as rivers will no longer be delivering sand – their mouths will be drowned. In New England, rock-bound steep shores will be safe, but overlying soft glacial material between rocks is already being attacked by rising seas and sea cliffs there are retreating at several meters per year, reshaping the coastline.
Sea level is only one dimension of climate change. Here in the Southwest we will have to deal mostly with changes in ecology, boundaries between ecosystems being sensitive to temperature and moisture. We are already seeing more dangerous wildland fires. And our water resources are already diminishing, as Ed Wolfe pointed out in a previous guest column.
It’s wise to remember that ecologic change in response to climate is worldwide, meaning that a billion subsistence farmers will find that their traditional crops are failing. Climate refugees are already an appreciable component of increasing migration patterns, and can only get worse. That will impact everyone, everywhere.
This was all predicted. I go back a long way on this, to the ’60s when Roger Revelle was showing via atmospheric measurements on Moana Loa that CO2 was increasing at greater-than-natural rates, and that simple thermodynamics predicted significant climate warming.
So we are handing an enormous problem to our children and grandkids. Again, referring to the letter of Oct. 11 criticizing youth actions, we should expect them to do nothing about it? They cannot afford to scoff like old folks can.
Eric Force is a former USGS geologist, currently an adjunct professor at the University of Arizona. For questions, email email@example.com and your inquiry will be forwarded. In the meantime, documentation can be found at GlobalChange.gov, www.ipcc.ch/reports, and www.ucsusa.org/underwater.