In his latest blog for Transition Voice, Prof. Guy McPherson of the University of Arizona provides us with an excellent reminder of just how urgent climate action is with a list of 19 natural phenomena that are exacerbating global warming. The list illustrates a point that we’ve written about in previous posts and frequently try to reinforce — unless we act quickly, the effects of climate change will be felt faster and harder than we tend to realize.
Warm Atlantic water is defrosting the Arctic as it shoots through the Fram Strait (Science, January 2011).
Global warming affecting the Arctic Circle. Photo: NASA Goddard Photo and Video/Flickr.
Siberian methane vents have increased in size from less than a meter across in the summer of 2010 to about a kilometer across in 2011 (Tellus, February 2011).
Drought in the Amazon triggered the release of more carbon than the United States in 2010 (Science, February 2011).
Peat in the world’s boreal forests is decomposing at an astonishing rate (Nature Communications, November 2011).
Invasion of tall shrubs warms the soil, hence destabilizes the permafrost (Environmental Research Letters, March 2012).
Surface meltwater draining through cracks in an ice sheet can warm the sheet from the inside, softening the ice and letting it flow faster, according to a study accepted for publication in the Journal of Geophysical Research: Earth Surface (July 2013). It appears a Heinrich Event has been triggered in Greenland. Consider the description of such an event as provided by Robert Scribbler on 8 August 2013:
In a Heinrich Event, the melt forces eventually reach a tipping point. The warmer water has greatly softened the ice sheet. Floods of water flow out beneath the ice. Ice ponds grow into great lakes that may spill out both over top of the ice and underneath it. Large ice damns (sic) may or may not start to form. All through this time ice motion and melt is accelerating. Finally, a major tipping point is reached and in a single large event or ongoing series of such events, a massive surge of water and ice flush outward as the ice sheet enters an entirely chaotic state. Tsunamis of melt water rush out bearing their vast floatillas (sic) of ice burgs (sic), greatly contributing to sea level rise. And that’s when the weather really starts to get nasty. In the case of Greenland, the firing line for such events is the entire North Atlantic and, ultimately the Northern Hemisphere.
Loss of Arctic sea ice is reducing the temperature gradient between the poles and the equator, thus causing the jet stream to slow and meander. One result is the creation of weather blocks such as the recent very high temperatures in Alaska. As a result, boreal peat dries and catches fire like a coal seam. The resulting soot enters the atmosphere to fall again, coating the ice surface elsewhere, thus reducing albedo and hastening the melting of ice. Each of these individual phenomena has been reported, albeit rarely, but to my knowledge the dots have not been connected beyond this space. The inability or unwillingness of the media to connect two dots is not surprising, and has been routinely reported (recently including here with respect to climate change and wildfires) (July 2013).
These phenomena are examples of what systems thinkers call “reinforcing feedback loops” in the Earth’s biogeochemistry. Another example of this kind of feedback loop would be a ball rolling down a hill. It needs a kick to start rolling, but once it’s off, it will keep rolling by itself.
This can be a frightening concept in the context of global warming, but we’re not powerless to stop it. Under different circumstances, many of these phenomena can also act as balancing feedback loops, which is what might happen when you roll a ball up a hill.
In other words, it’s all about momentum. Take McPherson’s fourth example, which shows that extra carbon is being emitted from droughts in the Amazon. This happens because dying plants are no longer able to absorb this carbon. The extra carbon makes the temperature hotter, which in turn can cause more droughts.
But what if we were planting more trees in the Amazon? This would mean less carbon in the atmosphere, cooler temperatures, and less droughts. It’s been said before: one of the Earth’s strongest potential balancing feedback loops is human action.