Continuation of Current Trajectory Hard to Avoid

By CIRCulator Editorial Staff

Reprinted from: The Climate CIRCulator

THE GLOBE’S current trajectory of energy use and carbon emissions most closely aligns with the worst-case emissions scenario (RCP8.5) from the latest set of four socioeconomic greenhouse gas concentration trajectories considered in the IPCC Fifth Assessment Report.

Because the four trajectories used in the report are not given likelihoods of occurring, they are difficult to weight by scientists and managers who are assessing climate change impacts.

In his recent talk at the Fifth Annual Pacific Northwest Climate Conference, Steve Davis of the University of California, Irvine, argued that the worst-case scenario should be considered a very real possibility, more likely than the others.

For the Northwest, this means 7 degrees to 14 degrees Fahrenheit of warming by 2100. (See CIRC’s climate chapter in the Northwest assessment report, 2013.)

What’s more, it would take substantial (and, Davis argues, implausible) collective action to change our current trajectory, though he notes signs of progress in the United States and elsewhere, much depends on what China does in the next decade or two.

The Fifth Annual Pacific Northwest Climate Conference drew researchers and practitioners to Seattle in September.

A version of this story originally appeared in the September 2014 issue of The Climate CIRCulator.