Sea-level Rise Predictions

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Since the 1980s computer model projections of climate change have underestimated this event. With greater advances in our understanding of the greenhouse’s effect on environmental change we have been able to make what scientists believe to be more accurate projections. However, recent radar studies of Antarctic ice mentioned in this New York Times article show there are likely more factors we are not aware of.

In this case we learn that warming ocean waters have created a huge cavity beneath one of Antartica’s ice sheets. Since most of this sheet lies above the ocean, if and when it breaks off, it could raise sea-level by as much as two feet within a short period of time–threatening coastal cities and many islands across the world.

As many environmental scientists have proposed, climate change might reach thresholds (i.e., tipping points) where unanticipated sudden catastrophic events might occur.

Global climate agreement finalized in Paris

A recent BBC article reported on implementing the Paris accord. Central to this agreement is limiting the amount of greenhouse gases emitted by human activity to the same levels that trees, soil and oceans can absorb naturally, beginning between 2050 and 2100. The report goes on to say that the Paris agreement, even if adhered to, is only a first major step to solving the climate change problem.

I’ve presented data in several of my earlier posts, along with a page of information from reputable scientific institutions. However, although data powerfully persuades scientists, it does not hold as much sway with the public. But photographs do. So here are some photos taken of the Grinnell glacier in Glacier National Park in northwestern Montana next to the Canadian border. In the three following photographs you will see the dramatic recession of this one glacier.

Grinnell Glacier Overlook: 1920
Grinnell Glacier Overlook: 1920
Grinnell Glacier Overlook: 1940
Grinnell Glacier Overlook: 1940

 

Grinnell Glacier Overlook: 2006
Grinnell Glacier Overlook: 2006
Public domain: USGS
Grinnell Glacier Overlook: 2013 (Public domain: USGS)

Although we know that recession would have started shortly after 1850, due to rising temperatures, note the dramatic difference between the 1940 and 2006 photographs. Collectively, these photographs are evidence of  climate change acceleration. Rephotographic evidence shows that all glaciers around the world are receding, and acceleration is fastest at the poles—all inline with historical studies of atmospheric and oceanic data.