‘Wedging’ the Climate

UCI professor urges further change to end the emission of greenhouse gases.


In a recent study published in the Environmental Research Letters, UC Irvine assistant professor of earth system science Steven J. Davis, along with three co-authors, stated urgency for the needed support of energy technology innovation in order to help combat the current changes in climate and emissions of greenhouse gases.

The study took an analytical look at the “wedge concept” wherein alternative, non-carbon emitting forms of energy will necessarily fill the wedges of a stabilization triangle — putting us on a path of stabilizing the atmospheric greenhouse gas concentrations.

Looking into the concepts of “wedges” of small implemented changes, the study followed the similar idea that each change in the scheme of energy production and consumption could effectively cut a wedge of greenhouse gases from the Earth’s burden — stabilizing carbon emissions and ultimately the issue of climate change on a global scale.

Criticizing the failures of implementing any change, the study primarily cites research published in 2004 by Pacala and Socolow, which argued that humanity could solve the issue of climate change over the scale of a 50-year period, by simply scaling up technology that scientists already possess.

“An unfortunate consequence of their paper, however, was to make the solution seem easy.

“In 2004, Pacala and Socolow concluded that ‘the choice today is between action and delay,’” the study said. “After eight years of mostly delay, that action now required is significantly greater.”

Alternatively, the study by Davis and his colleagues aims to prove that the issue is not as simple as has been previously portrayed by bringing together not only concepts of earth science, but also socioeconomic dependence on polluting energy forms.

“Stabilizing global climate requires decreasing CO2 emissions to near zero,” the study said. “But socioeconomic demands and dependence on fossil-fuel energy effectively commit us to many billions of tons of CO2 emissions, and at the timescale of centuries, each CO2 emission to the atmosphere contributes another increment to global warming.”

Extending the concepts put forward by Pacala and Socolow, which proposed seven wedges necessary for stabilization, Davis and his co-authors suggest that the current progression of increased greenhouse gases would require 19 wedges implemented over the course of the next 50 years to eliminate emissions.

“Nine to stabilize emissions and an additional 10 to completely phase-out emissions. And if historical, background rates of decarbonization falter, 12 ‘hidden’ wedges will also be necessary, bringing the total to a staggering 31 wedges,” the study said.

Although placed into the simplistic approach of filling each wedge while sustaining the global economy, Davis and his colleagues realize is not an easy feat. This change would require for tens of terawatts of clean energy to be produced over the next five decades — each terawatt the equivalent of burning 2,190,000,000 metric tons of oil.

“An integrated and aggressive set of policies and programs is urgently needed to support energy technology innovation across all stages of research, development, demonstration, and commercialization,” the study concluded. “No matter the number required, wedges can still simplify and quantify the challenge. But the problem was never easy.”