Tuesday, June 12, 2012

What about greenhouse gases?

As many readers of this blog would have noticed, I have been in favor of developing all different energy sources—nuclear, coal, oil, wind, solar. I advocate that position because more than three billion people still do not have adequate electricity and are mostly eking out subsistence. The society has an obligation to lift them out of poverty, and provide them with ample, affordable, and clean energy so they can live healthy productive lives. 
So what happens to greenhouse gases? Aren’t we then inexorably marching towards a calamity? Not if we recognize the need for a differentiated response. For starters, societies that have high per capita energy consumption can look for opportunities to conserve and and/or adopt more efficient technologies. As we do this, our focus should be on actions that can have a significant impact on greenhouse gas emissions, preferably on the short order.
Specific actions would differ for different societies. For people currently relying on foraging wood and burning it for fuel providing natural gas or electricity to would be highly beneficial. It would improve their health by limiting the exposure to sooty open flames, reduce deforestation, and reduce the warming due to soot. Since many of them are not currently supported by grid electricity, we should consider distributed power from appropriately sized wind or PV systems. 
Reining in fugitive natural gas during oil and gas production and from landfills is another important factor. Earlier this year, Shindell et al. published an article in Science pointing out the need to look at methane and black carbon sources. The paper showed that strategies to reduce methane and black carbon emissions would reduce the projected global warming by about 0.5°C. The paper emphasized the need for a differentiated response, as regional differences are important. For example in the US, natural gas emissions are mostly associated with municipal waste (ca. 50%), and less so with oil and gas operations (ca. 12%; additional 12% from coal mining). Methane from O&G operations contributed much more in Russia, Middle East, and Central Africa. While the new EPA regulations on methane emissions from shale gas are important to ensure that this energy source does not become a major culprit, we should not lose sight of methane emissions from landfills. Innovations to economically use landfills as a resource for electric power production would have a larger impact on reducing greenhouse gases. 
Another leverage point for reducing greenhouse gases is agriculture. As we discuss in our book, reducing beef consumption in our diet can make a very large difference by impacting at multiple levels. Fewer cattle would burp out less methane and require less feed—feed that is in turn produced by using energy intensive fertilizers, etc. By using controlled-release fertilizers or by using biochar as soil amendment, we can further reduce both the amount of fertilizer used and the efficiency of its uptake by the plants.  These measures are not as exciting or trendy but they can have a substantial impact on GHG emissions and are deserving of our attention.
In an Op-Ed in the NY Times (May 9, 2012), James Hansen declared that if Canada develops its tar sands resources it is “Game Over” for climate change. His point is that developing tar sands and other unconventional sources such as shale oil would detract from efforts to “phase out our addiction to fossil sources.” I see the recent rise in the production of unconventional resources as a welcome relief from the energy crunch that we were facing. It takes decades to develop alternate energy sources like solar, wind, and geothermal, and with the recent closure of nuclear plants in Japan and Germany, there is increasing pressure to find CO2-free sources of energy. At present they are significantly more expensive, and it would take further innovations to bring their costs down and get them ready for widespread commercialization. Shale gas, shale oil and other unconventional resources are helping us buy time to develop CO2-free sources of energy. It would be criminal to waste this precious gift of time.

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