Sleepwalking toward a new ecology

The pace of ecological change is quickening and I see little sense of urgency to address the negative consequences that are unfolding. The increasing speed of change is a direct consequence of two interacting drivers – resource use and climate change. The long standing processes of human use of natural resources and resulting habitat degradation have increased in scale and impact as our population has continued to explode. Adding to this, as defense analysts have argued, climate change is both a primary driver and amplifier of change. Collectively these factors are driving worldwide ecosystem change at a pace and scale far exceeding any previous period of change in the history of our planet at least since the demise of the dinosaurs. Continue reading “Sleepwalking toward a new ecology”

Linkage between extreme weather and climate change

This is a posting from 2011 about extreme weather. Obviously, this is an appropriate topic this winter.  Since writing this several years ago, I have come to see all weather as taking place in a human altered climate.  Thus, the appropriate question is not whether a particular event such as Superstorm Sandy was caused by climate change, but instead to understand those characteristics of the event that have been altered by climate change.  For Katrina such an association is not particularly compelling, although the sea surface temperatures in the Gulf were very high.  For Superstorm Sandy, there are several characteristics that may be linked to human caused climate change.


Intermountain Climate

When I speak about climate change I always remind my audiences to not conflate climate with weather.  For example, Katrina is best seen as an extreme weather event that cannot be mechanistically linked to anthropogenic climate change.  Even scientists, including me, can lapse into sloppy thinking about individual weather events and declare, as I did in the heat of the moment, that events like Katrina are the smoking gun of human-caused climate change.  Nonsense.  Although I am embarrassed by my early lack of rigor, this mistake provided me with an important opportunity to study the stochastic nature of weather and its linkage to ongoing climate change.  The term stochastic means that a weather event such as Katrina is driven by both deterministic and random factors.  To be sure, Katrina was perhaps indicative of the kind of storm that modelers think will be increasingly typical of storms in the Anthropocene.  As an…

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Warming has not stopped: Surface temperatures reflect multiple forcing factors

Recently there has been a lot of chatter on various denier blogs about the notion that global warming stopped in 1998.   Moreover, I am finding that thoughtful, well-read individuals who generally accept the concept of anthropogenic climate change are hoping that warming has peaked and that the planet will soon begin to cool.  Usually some unspecified “natural cycle” is identified as the cause of this cooling.   This meme seems to be gaining traction with a growing cross section of the public.  This article in The Daily Mail is typical of the logic behind this idea, and the figure below from Gavin Schmidt at RealClimate provides what appears to be compelling evidence to support this claim. Continue reading “Warming has not stopped: Surface temperatures reflect multiple forcing factors”

Climate lessons from Sandy and the political economy of mitigation

There is compelling evidence that certain features of Sandy can be linked to climate change, and it is clear that scientific studies of this linkage will be undertaken over the next few months and years.  That said, as a scientist I am increasingly impressed with the emphasis that many folks place on weather as an indicator of human caused climate disruption. Continue reading “Climate lessons from Sandy and the political economy of mitigation”

The case for leaving the carbon in the ground

Jim Hansen has used the phrase “essentially game over” when referring to the greenhouse gas emissions that would ensue from the use of Tar Sands oil as an energy source.  To be sure, there is one heck of a lot of carbon in this one source, and Bill McKibben has referred to the proposed pipeline as the “fuse to the biggest carbon bomb on the planet.” Continue reading “The case for leaving the carbon in the ground”