

I talk about loaded climate “dice” and March heat records on The Takeaway:

James E. Hansen, the longtime climate scientist who has turned increasingly to activism in recent years, has updated his analysis of how the buildup of human-generated greenhouse gases is loading the climate “dice” so that hotter extremes are ever more likely.

I talked with him in 2008 about his use of this apt metaphor. Here’s the video of our chat:

Here’s the abstract of his latest draft paper, “Public Perception of Climate Change and the New Climate Dice”:

“Climate dice,” describing the chance of unusually warm or cool seasons relative to climatology, have become progressively “loaded” in the past 30 years, coincident with rapid global warming. The distribution of seasonal mean temperature anomalies has shifted toward higher temperatures and the range of anomalies has increased. An important change is the emergence of a category of summertime extremely hot outliers, more than three standard deviations… warmer than climatology. This hot extreme, which covered much less than 1% of Earth’s surface in the period of climatology, now typically covers about 10% of the land area. It follows that we can state, with a high degree of confidence, that extreme anomalies such as those in Texas and Oklahoma in 2011 and Moscow in 2010 were a consequence of global warming, because their likelihood in the absence of global warming was exceedingly small. We discuss practical implications of this substantial, growing, climate change.

Another veteran climatologist, John Michael Wallace of the University of Washington, sees a similar message in extreme events in relation to the background push from greenhouse gases, but says efforts to demonstrate that today’s heat waves are driven substantially by greenhouse heating can be a damaging distraction.

Here’s the nut of “Weather- and Climate-Related Extreme Events:

Teachable Moments,” his recent essay in the American Geophysical Union publication Eos (click for pdf):

Arguing about whether or not today’s extreme events are early indicators of climate change does nothing to advance the priority of global warming and other pressing environmental issues on our national policy agenda. The real significance of extreme events is as harbingers, not just of a changing climate but also of a changing world in which human society and the infrastructure that supports it are becoming increasingly vulnerable to natural disasters. The mounting disruptions in their wake reveal the progressive deterioration of our planetary life-support systems. Extreme events are, indeed, teachable moments: “wake-up calls” that an environmental crisis of global proportions is imminent—much more so than the subtle and sometimes ambiguous early warning signs of global warming might lead us to believe.

I encourage you to read this prescient excerpt from a remarkable 1981 paper by Jim Hansen and collaborators on global warming (noticed via RealClimate and Jason Major at Universe Today):

Political and economic forces affecting energy use and fuel choice make it unlikely that the CO2 issue will have a major impact on energy policies until convincing observations of the global warming are in hand. In light of historical evidence that it takes several decades to complete a major change in fuel use, this makes large climate change almost inevitable. However, the degree of warming will depend strongly on the energy growth rate and choice of fuels for the next century. Thus, CO2 effects on climate may make full exploitation of coal resources undesirable. An appropriate strategy may be to encourage energy conservation and develop alternative energy sources, while using fossil fuels as necessary during the next few decades. The climate change induced by anthropogenic release of CO2 is likely to be the most fascinating global geophysical experiment that man will ever conduct. The scientific task is to help determine the nature of future climatic effects as early as possible. The required efforts in global observations and climate analysis are challenging, but the benefits from improved understanding of climate will surely warrant the work invested.

The political and economic realities described by Hansen and his co-authors were reflected in a different way in a pioneering article on carbon dioxide and climate published in The Times in 1956:

Coal and oil are still plentiful and cheap, and both will be consumed by industry so long as it pays to do so.

As I wrote when I last cited this, “The only change I’d suggest is to drop the words ‘by industry,’ given that everyone in societies thriving on fossil fuels has harvested the present benefits while largely discounting, so far, the need to invest against long-term risks from the resulting buildup of greenhouse gases. (And of course I’d add natural gas to the fuel mix.)

Indeed, the entwined climate and energy challenges are “beyond super wicked,” which is why I am among those focused on building the human capacity for resilience, inventiveness and awareness.