IS CARBON MITIGATION UNDER ATTACK?
August 21, 2018 § Leave a comment
The US administration appears to have fired a salvo against carbon mitigation. We will examine the facts and muse on the likely true impact of the government action. A recent story discusses the implications of a directive seemingly buried in a memorandum on fuel economy standards from a month ago. I am unable to find the one memorandum, but earlier documents for public comment are clear on a couple of measures, which are quoted in the linked story. These include, freezing fuel economy standards to 2020 planned levels.
Ironically, this comes at a time when completely unprecedented forest fires rage worldwide. Since this was more or less predicted by earlier temperature rise models, the increased frequency of fires is believed to have anthropogenic origins, as noted in a recent PNAS paper. The impact of forest fires is profound. The economic privation is high as is the long term impact on health.
Health impact of emissions from combustion
Even climate change deniers must accept the epidemiologically supported finding that airborne particulate matter (PM) is responsible for 6.5 million premature deaths, annually, worldwide. Nearly two thirds of the mortality figure is attributed to wood burning for cooking and heating. Forest fires are country cousins, in terms of type of particles emitted. They are spectacular and frightening, but in the overall scheme, currently account for minor contributions to airborne particulates. But, to the extent they are driven by temperature rise, this contribution can only increase, even as other anthropogenic PM diminishes due to interventions.
Over 80% of airborne particulates are sourced from either the creation or use of energy. On the consumption side, the biggest contributor in the US and Europe urban communities is automotive exhaust. While diesel gets all the press, gasoline also is a contributor, particularly of ultrafine particles, which are especially toxic. Both also produce NOx and organics, which are responsible for atmospheric reactions with the particles, often involving ozone and mediated by photochemical action, rendering them more toxic. There ought to be little dispute that reducing these emissions ought to be a federal objective. Two measures can accomplish that: engineered mitigation of emissions, such as better diesel particulate filters, or decreased use of fuel. The objective of using less fuel, while obtaining the same utility, can only be attained with better engine efficiency.
Implications of the new guidelines
One of the directives is the relaxing of fuel economy standards, by holding them constant at 2020 levels. This runs counter to the point made above, regarding means to reduce the impact of airborne particulate matter. Since no companion guidelines are provided regarding PM capture, on these grounds alone, the new guidelines are unfriendly to the goal of reduced particulate emissions. Admittedly, mortality figures associated with PM in the US are small compared to the world figure noted above. A recent paper estimates it to be 138,000 annually in the early 21st century, about 5.1% of total deaths. That is more than double those attributed to influenza and pneumonia, for which serious intervention measures exist.
In the linked story, the memorandum is quoted as stating that growth of natural gas and other alternatives to petroleum have reduced the need for imported oil, which “in turn affects the need of the nation to conserve energy.” The gist of the story is that the administration believes that conserving oil is no longer in the national interest. Without doubt the proliferation of cheap shale gas has allowed many commodities to be made profitably from natural gas, instead of from oil. Since the US is a net importer of oil, such use of gas does reduce oil import.
However, due to shale production the US is already the leading producer of oil and gas. Nevertheless, it still imports oil, while also exporting both fluids. A lot of this trade is with Canada and Mexico. I predict that within five years North America will be self-sufficient in oil and gas. Accordingly, from the standpoint of national energy security, conservation is not needed (provided we don’t emasculate NAFTA in the energy sector). But the plea in this blog is that it is needed to preserve the health of the citizenry. And it is not conservation, per se, that we seek. Simply, the more prudent use of energy for no less gratification. Drive the same miles, stay just as warm (or cool), but do it more efficiently.