June 21, 2010 | General

Biomass Energy Outlook: CO2 Emissions Down Remarkably In 2009

BioCycle June 2010, Vol. 51, No. 6, p. 37
Mark Jenner

The U.S. Energy Information Administration (EIA) has determined that carbon dioxide (CO2) emissions in the U.S. have declined by 405 million metric tons in 2009, or 7.0 percent! This is in addition to the 3 percent decline in 2008. The declines for the last two years take the U.S. CO2 emissions back to nearly 1995 levels without any significant new carbon policy.
Much of this scaling back of CO2 emissions is related directly and indirectly to the contraction of the U.S. economy. Reducing CO2 emissions via this economic crisis is like claiming diet-like weight loss from being sick. We all need the economy to snap back soon – hopefully without a corresponding rebound of carbon emissions.
The EIA provides some compelling reasons for the decline that go beyond massive cutbacks in energy consumption due to the economic recession. These include changes in technology and switching to fuels with lower carbon intensities. The moral of the story is that we really can change.
EIA describes the 7 percent drop in roughly equal declines in Gross Domestic Product (GDP), energy intensity and carbon intensity. The decline in GDP is the direct indicator of the economic recession. The other two units are more complicated. Both energy and carbon intensity are influenced by the economic downturn but in less direct ways. EIA defines energy intensity as energy consumed per unit of economic activity or (Btu/GDP). Carbon intensity is defined as carbon dioxide emissions per unit of energy consumption (CO2/Btu).
Because the energy intensity measure includes GDP in the denominator, it is certainly influenced by the economic activity. Curiously because GDP is in the denominator, as the GDP shrinks the energy intensity would intuitively get larger. However, it did not increase when the GDP decreased. The energy intensity declined by nearly the same amount as the GDP. For this to happen, it requires a much greater decline in the amount of energy consumed (Btu) than the decline in the GDP.
The amount of energy consumed did drop remarkably in the transportation sector. In 2008, transportation fuels declined 7.1 percent from 2007. In 2009, the transportation sector declined another 3.2 percent. EIA also credits improvements in the fuel economy of the total U.S. fleet from 27 miles per gallon (mpg) in 2008 to 28.5 mpg in 2009. While that increase in fuel efficiency may seem trivial, it is more than 5 percent! And it is only beginning. The automobile manufacturers are increasing their lines of fuel-efficient models and scaling back on the fuel hogs (GM ceased production of the fuel-consumptive Hummer in May). It has taken decades to build a culture of fuel conservation, but it seems to be happening.

Part of the EIA CO2 emission explanation is that energy and carbon intensities have mellowed. A large reason for declines in the U.S. energy intensity is due to declines in energy-intense primary manufacturing activity. Industries such as primary metals and nonmetallic minerals were more adversely affected by the economic downturn because they require more energy than other sectors. Hopefully, as the economy recovers, these sectors will resume their valuable role in the economy. Unless they can upgrade their technologies or switch to lower carbon fuels as some power plants have, they may well resume former emissions levels.
The carbon intensity of the U.S. fuel supply also has decreased. EIA reports that fuel sources have switched from coal to natural gas, due to lower prices for natural gas. This is pretty interesting because the CO2 emissions from natural gas are about half the CO2 emissions from coal on a Btu basis. So for every Btu of natural gas consumed, about half the CO2 is emitted. Also wind energy capacity has increased 11 fold – 65,000 million kilowatt hours (kWh) from 2000 levels. During the same ten year period, utilization of existing nuclear power capacity increased by 45,000 million kWh.
The EIA also presented data showing that newer natural gas power plants that have come online since 2000 have become more efficient. Metric tons of CO2 emissions from natural gas power plants have dropped 18 percent in the last 10 years from 0.542 to 0.445 metric tons per thousand kWh. The real solution to gains from both economic growth and higher environmental quality is through gains in technical efficiency.
This EIA analysis on the declines in U.S. CO2 emissions in 2009 is disturbing from the standpoint that it illustrates the multiyear impact of the floundering U.S. economy. The lack of disposable income has taken the fun out of our excess fuel consumption. The story is not over.
As the economy recovers, our energy-intensive industries will hopefully come back online also. A risk that remains as we develop U.S. carbon policies in the new green economy is that excessive regulations on CO2 emissions may force U.S. industries to other countries. Even if they restart production at former emission levels, I believe we are further ahead by keeping our industrial economic engines within our borders and helping them become more carbon efficient than we are exporting the jobs and CO2 emissions to countries outside U.S. jurisdiction.
The silver-lining here is that it isn’t all about the economic losses. Advances in technology and shifts to lower carbon fuels are outcomes that will likely rebound with the economy. Amid the economic chaos, there is hope for a greener tomorrow.

Mark Jenner, PhD, and Biomass Rules, LLC, has joined the California Biomass Collaborative. Burning Bio News and other biomass information is available at www.biomassrules.com.

Sign up