[Due to the increasing size of the archives, each topic page now contains only the prior 365 days of content. Access to older stories is now solely through the Monthly Archive pages or the site search function.]
EPA qualifies new biogas and electricity pathways for cellulosic biofuel requirement under RFS; defers decision on other proposed pathways
July 03, 2014
In a newly released rule, the US Environmental Protection Agency (EPA) has clarified the number of cellulosic biofuel renewable identification numbers (RINs, earlier post) that may be generated for fuel made with feedstocks of varying cellulosic content; qualified additional fuel pathways to meet the lifecycle greenhouse gas (GHG) reduction requirements for cellulosic biofuel under the National Renewable Fuel Standard (RFS) program; and clarified or amended a number of RFS program regulations that define terms or address registration, record-keeping, and reporting requirements. The final rule also clarifies that EPA considers corn kernel fiber to be a crop residue.
However, the final rule differs in several ways from the Notice of Proposed Rulemaking EPA had issued in June 2013 (earlier post):
NASA’s Orbiting Carbon Observatory 2 reaches orbit
July 02, 2014
by Jack Rosebro
At 2:56 AM PST today, NASA’s Orbiting Carbon Observatory 2 (OCO-2) was successfully launched into orbit from Space Complex 2 West at California’s Vandenberg Air Force Base, riding on a two-stage Delta II 7320-10 launch vehicle. Consisting of a single observing instrument, the Observatory is designed to provide precise measurements of atmospheric CO2, and is NASA’s first satellite mission dedicated to studying concentrations of carbon dioxide in the atmosphere.
OCO-2 will not be measuring CO2 directly; but rather the intensity of the sunlight reflected from the presence of CO2 in a column of air. This measurement is unique like a fingerprint, and can be used for identification. The OCO-2 instrument will use a diffraction grating to separate the incoming sunlight into a spectrum of multiple component colors.
EPA proposes rule for nationwide 30% cut in GHG from existing power plants by 2030 relative to 2005
June 02, 2014
The US Environmental Protection Agency (EPA) released the already widely-discussed (albeit without much detail) “Clean Power Plan” proposal, which mandates a national average 30% cut in greenhouse gas emissions from existing power plants from 2005 levels by 2030. Power plants accounted for 32% (2,064 million metric tons of CO2 equivalent) of all domestic greenhouse gas emissions in the United States in 2012, according to the EPA.
Specifically, the EPA is proposing state-specific rate-based goals for carbon dioxide emissions from the power sector, as well as emission guidelines for states to use in developing plans to attain the state-specific goals. Each state’s goal is different, because each state has a unique mix of emissions and power sources to plug in to each part of the formula. The Clean Power Plan broadly proposes:
Environment Canada/MECA team assesses black carbon emissions in GDI engine exhaust; evaluation of prototype gasoline particulate filter
Although gasoline direct injection engines (GDI) are a favorable technology for reducing fuel consumption and greenhouse gas emissions, recent studies have shown that GDI vehicles could emit more PM than traditional PFI (gasoline port fuel injection) vehicles as well as heavy-duty diesel trucks equipped with diesel particulate filters. This may result in the need for new emissions control strategies—such as a gasoline particulate filter (GPF)—to enable compliance with California LEV III and US EPA Tier 3 particulate emissions standards.
Now, a team from Environment Canada and Manufacturers of Emission Controls Association (MECA) report on an evaluation of emissions from two pairs of GDI and PFI (gasoline port fuel injection) vehicles over two different drive cycles and at different ambient temperatures to understand how solid particle number and BC mass relationships vary under the influence of different factors. Their paper appears in the ACS journal Environmental Science & Technology.
Study estimates global black carbon emissions up 72% from 1960-2007; BC emissions intensity down 52%
May 31, 2014
|Black carbon emissions and BC emissions intensity per year. Credit: ACS, Wang et al. Click to enlarge.|
A study led by a team from Peking University has estimated that global black carbon (BC) emissions increased from 5.3 teragrams/year in 1960 to 9.1 teragrams per year in 2007 (+72%). These estimates are 11-16% higher than produced by in previous inventories, the researchers noted in a paper published in the ACS journal Environmental Science & Technology.
Over the same period, BC emission intensity—the amount of BC emitted per unit of energy production—decreased by 52% for all the regions under assessment, especially China and India.
UCS analysis finds Hyundai-Kia with best sales-weighted new vehicle environmental performance in US in 2013
May 27, 2014
|Click to enlarge.|
In its sixth sales-weighted analysis of emissions from 8 major automakers’ 2013 model year vehicles, the Union of Concerned Scientists’ (UCS) latest Automaker Rankings report found that Hyundai-Kia unseated Honda as the “Greenest Automaker.” Honda came in second, with Toyota, Nissan, and Volkswagen in a three-way tie for third place.
For the first time since UCS began the Automaker Rankings report in 2000, all eight major automakers reduced their average greenhouse gas (GHG) and smog-forming emissions compared to their fleet averages from 1998, the model year examined in the first report. The Automaker Rankings report examines the emissions of both global warming and smog-forming pollution from of the automakers. Due to strong federal and state emissions standards, the average new car has gotten 43% cleaner since 1998.
ARB: carbon intensity of biomethane from wastewater sludge could be as low as -65.27 g CO2e/MJ
May 22, 2014
The staff of the California Air Resources Board (ARB) staff has posted three new Low Carbon Fuel Standard (LCFS) fuel pathway applications to the LCFS public comments website: one for corn ethanol (from Heartland Corn Products in Minnesota) and one ARB staff-developed pathway (with two scenarios) for the production of biomethane from the mesophilic anaerobic digestion of wastewater sludge at a wastewater treatment plant (WWTP) located at a publicly-owned treatment works (POTW).
Under the LCFS, the baseline CI value for gasoline was 95.86 g CO2e/MJ; for diesel fuel, 94.71 g CO2e/MJ. Staff estimated the carbon intensities (CIs) for biomethane produced under two alternative scenarios; under the first scenario, the CI of biomethane is 10.86 g CO2e/MJ; under the second, the CI is -65.27 g CO2e/MJ—i.e., it generates a credit.
Ford researchers: global light-duty CO2 regulatory targets broadly consistent with 450 ppm stabilization
May 15, 2014
An analysis by researchers at Ford Motor Company Research and Advanced Engineering in Dearborn and Ford Forschungszentrum in Germany concludes that existing global light-duty vehicle CO2 regulations through 2025 are broadly consistent with the light-duty vehicle (LDV) sector contributing to stabilizing CO2 at an atmospheric concentration of approximately 450 ppm—a target often proposed in the literature as preventing dangerous climate change. Their paper is published in the ACS journal Environmental Science & Technology.
In the study, the Ford team derived regional CO2 targets for new LDVs while still providing an integrated view of the global LDV fleet—a perspective critical to the planning needs for global automotive firms. The teams calls the time-varying LDV targets “CO2 glide paths”.
Study finds rising temperatures increase risk of unhealthy ozone levels absent sharp cuts in precursors
May 05, 2014
Ozone pollution across the continental United States will become far more difficult to keep in check as temperatures rise, according to new work led by the National Center for Atmospheric Research (NCAR). The study shows that Americans face the risk of a 70% increase in unhealthy summertime ozone levels by 2050, assuming continued greenhouse gas emissions with resultant significant warming (IPCC Scenario A2 and RCP (Representative Concentration Pathway) 8.5.)
However, the study also showed that a sharp reduction in the emissions of ozone precursors would lead to significantly decreased levels of ozone even as temperatures warm. Without those cuts, almost all of the continental United States will experience at least a few days with unhealthy air during warmer summers, the research shows. Heavily polluted locations in parts of the East, Midwest, and West Coast in which ozone already frequently exceeds recommended levels could face unhealthy air during most of the summer.
Cambridge study of near-term alternative London bus technologies finds lean-burn CNG most costly with greater climate impact than diesel
May 01, 2014
Researchers from the University of Cambridge have conducted a comprehensive environmental cost–benefit analysis of near-term alternative bus technologies. The study considered emissions of non-methane hydrocarbons (NMHC), CO, NOx, PM2.5, sulfur dioxide (SO2), and ammonia (NH3), as well as the lifecycle climate impact of CO2 and non-CO2 greenhouse gases (GHG) on a CO2-equivalent basis.
Their findings indicated that emission control strategy retrofits are the least costly near-term intervention to reduce urban air pollution. Although hybrid buses provide net GHG reductions and air quality improvements, associated costs are higher and more uncertain than emission retrofits. Lean-burn (spark ignition) compressed natural gas (LB-CNG) delivers the lowest health impacts due to the significant reduction of PM2.5, but has relatively high associated CO2e emissions that negate the health benefits, they found. As a result, current LB-CNG vehicles are the most costly of all of the modeled technologies, they concluded. Their study appears in the ACS journal Environmental Science & Technology.
EPA: US greenhouse gases dropped 3.4% in 2012 from 2011; down 10% from 2005 levels
April 16, 2014
|US greenhouse gas emissions by gas. Source: EPA. Click to enlarge.|
The US Environmental Protection Agency (EPA) released its 19th annual report of overall US greenhouse gas (GHG) emissions, showing a 3.4% decrease in 2012 from 2011. The Inventory of U.S. Greenhouse Gas Emissions and Sinks, which is submitted annually to the Secretariat of the United Nations Framework Convention on Climate Change, presents a national-level overview of annual greenhouse gas emissions since 1990.
Total emissions of the six main greenhouse gases in 2012 were equivalent to 6,526 million metric tons of carbon dioxide. These gases include carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride. According to the report, GHG emissions in 2012 showed a 10% drop below 2005 levels, and were only slightly above the emissions in 1994 (6,520 million metric tons).
World Bank/ICCT report provides guidance to reducing black carbon emissions from diesels in developing countries
April 14, 2014
|Historical Trends in Black Carbon Emissions from Surface Transportation (teragrams of black carbon per year). Source: Minjares et al. Click to enlarge.|
The World Bank has published a report, undertaken by a team from the International Council on Clean Transportation (ICCT), intended to inform efforts to control black carbon emissions from diesel-based transportation in developing countries. The report proposes approaches for integrating black carbon emission reduction considerations in cost-benefit assessment and applies an analytic framework to four simulated projects to illustrate the associated opportunities and challenges at a project level.
The transportation sector accounted for approximately 19% of global black carbon emissions in the year 2000, according to the report. Road transportation accounted for 9% of global black carbon, with diesel engines responsible for nearly 99% of those emissions. In the near term, black carbon emissions from mobile engines are projected to decline as a consequence of policies implemented in the US, Canada, Europe, and Japan. However, black carbon emissions are projected to increase in the next decade as vehicle activity increases, particularly in East and South Asia.
IPCC: GHG emissions accelerating despite mitigation efforts; major institutional and technological change required to keep the heat down
April 13, 2014
The UN Intergovernmental Panel on Climate Change (IPCC) released a policymaker’s summary of Working Group III’s (WG III) latest report showing that despite a growing number of climate change mitigation policies, annual anthropogenic GHG emissions grew on average by 1.0 giga tonne carbon dioxide equivalent (GtCO2eq) (2.2%) per year from 2000 to 2010 compared to 0.4 GtCO2eq (1.3%) per year from 1970 to 2000. Total anthropogenic GHG emissions were the highest in human history from 2000 to 2010 and reached 49 (±4.5) GtCO2eq/yr in 2010. The global economic crisis 2007/2008 only temporarily reduced emissions.
The increase in anthropogenic emissions comes directly from energy supply (47%); industry (30%); transport (11%); and buildings (3%) sectors, the WG reported with medium confidence. Globally, economic and population growth continue to be the most important drivers of increases in CO2 emissions from fossil fuel combustion.
Joint Research Centre review concludes no serious risk in use of R1234yf MAC refrigerant under normal and foreseeable conditions
March 07, 2014
A scientific review of research regarding the safety aspects of the use of refrigerant R1234yf in Mobile Air Conditioning (MAC) systems, published by the European Commission, concludes that there is no evidence of a serious risk in the use of this refrigerant in MAC systems under normal and foreseeable conditions of use.
The review, carried out by Europe’s Joint Research Centre, provided an in-depth analysis of testing and a subsequent report on the refrigerant’s safety by KBA (Kraftfahrt Bundesamt, the German authority responsible for market surveillance and product safety for road vehicles) in order to ascertain whether the results stemming from the tests were well founded and supported by a rigorous and scientific methodology.
Chevy buying carbon credits from US colleges; new formula helps fund campus energy-efficient projects
February 12, 2014
Chevrolet is investing in clean energy efficiency initiatives of US colleges and universities through its voluntary carbon-reduction initiative. The funding opportunity is open to all US universities and colleges; a campus determines whether its performance in reducing carbon emissions will qualify based on new methodologies that Chevrolet developed through the Verified Carbon Standard.
To develop the new methodologies, Chevrolet worked with an advisory team led by the Climate Neutral Business Network with support from the Bonneville Environmental Foundation, the US Green Building Council and the Association for the Advancement of Sustainability in Higher Education (AASHE).
Calif. ARB releases GHG scoping plan update; more ZEVs, “LEV IV”, MD and HD regulations; ZEV for trucks; more LCFS
February 11, 2014
The California Air Resources Board released the draft proposed first update to the AB 32 Scoping Plan, which guides development and implementation of California’s greenhouse gas emission reduction programs. The Air Resources Board is required to update the Scoping Plan every five years.
Among the actions proposed or considered in the transportation sector include aggressive implementation of the light-duty Zero Emission Vehicle standard; LEV IV emissions regulations for the light-duty fleet post-2025 (GHG reductions of about 5% per year); Phase 2 GHG regulations for medium and heavy-duty (MD and HD) vehicles; a possible ZEV regulation for trucks; more stringent carbon reduction targets for the Low Carbon Fuel Standard; and others.
Analysis finds air-quality justification for CNG vehicle conversion in developing cities, despite negative climate impact
December 03, 2013
|Impact pathway approach for modeling policy interventions in (a) air quality and (b) climate impacts. Credit: ACS, Zia and Tanzila. Click to enlarge.|
An analysis by a team in Bangladesh found large air quality and associated health benefits accruing to the residents of Dhaka (the capital of Bangladesh) as a result of the rapid conversion of the motor vehicle fleet to CNG. Around 2,045 avoided premature deaths in greater Dhaka can be attributed to air quality improvements from the CNG conversion policy in 2010, resulting in a saving of around US$400 million, they found.
However, CNG conversion was apparently detrimental from a climate change perspective, as CH4 emissions increased. (There is some uncertainty over the impact of ultrafine particulates.) As the greenhouse gas impacts (costs or benefits) are much smaller than the health benefits, the conversion of petroleum vehicles to CNG can be justified on the basis of local air pollution benefits alone, they concluded. Their paper is published in the ACS journal Environmental Science & Technology.
Berkeley Lab modeling study finds California will not meet 2050 GHG targets without additional policy measures
November 05, 2013
|Comparison of GHG emissions by study scenario, along with historical and “straight-line” connections between 2020 and 2050 policy targets. 85 MtCO2/yr (red square) is the 2050 target. Greenblatt 2013. Click to enlarge.|
California will attain its 2020 statewide greenhouse gas reduction targets, according to a new modeling study by Jeffery Greenblatt at Lawrence Berkeley National Laboratory.
However, while all of the three scenarios developed for the study achieved the 2020 target, none were able to achieve the 2050 GHG target of 85 MtCO2/yr, instead yielding emissions ranging from 188 to 444 MtCO2/yr. Therefore, Greenblatt concluded, additional policies will need to be developed for California to meet this stringent future target.
U-Mich researcher’s first-principles analysis challenges conventional carbon accounting for biofuels; implications for climate policy
September 24, 2013
In a paper that could have a significant impact on climate policies for transportation fuels, Dr. John M. DeCicco of the Energy Institute at the University of Michigan, Ann Arbor presents a rigorous first-principles analysis that undermines the common “biofuels recycle carbon” argument.
Published in the journal Climactic Change, the open access paper shows that while the carbon mitigation challenge for liquid fuels has been seen—incorrectly—as a fuel synthesis and substitution problem, it is in reality a net carbon uptake problem. Accordingly, DeCicco concludes, strategies should move away from a downstream focus on replacing fuel products to an upstream focus on achieving additional CO2 uptake through the most cost-effective and least damaging means possible. “All parties with an interest in the issue are advised to rethink their priorities accordingly,” he finishes.
EPA proposes CO2 emission standards for new fossil fuel-fired power plants
September 20, 2013
The US Environmental Protection Agency (EPA) has proposed Clean Air Act standards to reduce CO2 emissions from fossil-fuel fired power plants (electric utility generating units, EGUs). For purposes of this rule, fossil fuel-fired EGUs include utility boilers, IGCC units and certain natural gas-fired stationary combustion turbine EGUs that generate electricity for sale and are larger than 25 megawatts (MW). In addition, EPA said it is working with state, tribal, and local governments, industry and labor leaders, non-profits, and others to establish CO2 standards for existing power plants.
The proposed rulemaking establishes separate standards for natural gas and coal plants. The proposed limits for natural gas units are based on the performance of modern natural gas combined cycle (NGCC) units. New large (>850 mmBtu/h) natural gas-fired turbines would need to meet a limit of 1,000 pounds of CO2 per megawatt-hour, while new small (≤850mmBtu/h) natural gas-fired turbines would need to meet a limit of 1,100 pounds of CO2 per megawatt-hour.
UT Austin team and partners report on extensive measurements of methane emissions during natural gas production
September 17, 2013
|Estimated inventories of methane emissions from the natural gas production sector, excluding processing and transmission. The findings of the new study are represented in the yellow bar at right, and are similar overall to EPA’s latest inventory. The relative contributions of different production components differ, however. Source: UT Austin. Click to enlarge.|
A new study from The University of Texas at Austin, published as an open access paper in Proceedings of the National Academy of Sciences reports on extensive measurements of methane emissions—including the first measurements for methane emissions taken directly at the well pad—during completion operations for hydraulically fractured wells (“fracked”).
Broadly, the study found that completion emissions are significantly lower than previously estimated; emissions from pneumatic controllers and equipment leaks are higher than EPA national emission projections; and estimates of total emissions (957 Gg ± 200 Gg) are similar to the most recent EPA national inventory of methane emissions from natural gas production (~1200 Gg). The 957 Gg in emissions for completion flowbacks, pneumatics and equipment leaks, coupled with EPA national inventory estimates for other categories, leads to an estimated 2,300 Gg of methane emissions from natural gas production (0.42% of gross gas production).
DOE and Air Force issue RFI on Mil-Spec jet fuel production using coal-to-liquid technologies
September 05, 2013
The US Department of Energy (DOE) in partnership with the US Air Force has issued a request for information (RFI)—DE-FOA-0000981—on research & development aimed at greenhouse gas emissions reductions and cost competitiveness of Mil-Spec jet fuel production using coal-to-liquid (CTL) fuel technologies.
The DOE’s National Energy Technology Laboratory (NETL), on behalf of the US Air Force, intends to issue a funding opportunity announcement (FOA) in 2013 that would solicit for the most promising research and development projects on advanced concepts for and/or unit operations within a CTL fuels plant; the areas of interest may be developed based in part on the responses to the RFI. The DOE and US Air Force anticipate the need for projects of no less than $3 million and that would have duration of not more than 3 years.
World Bank to focus on reducing short-lived climate pollutants; transport projects
September 04, 2013
|Aggregation of SLCP project activities into typologies. Click to enlarge.|
A new report prepared by the World Bank at the request of the G8 identifies ways that the World Bank can do more through its projects to reduce the emission of short-lived climate pollutants (SLCPs): black carbon, methane, tropospheric ozone, and fluorinated gases known as HFCs.
The review, “Integration of Short-Lived Climate Pollutants in World Bank Activities,” highlights ways the Bank’s investments are already reducing SLCPs and shows where potential exists for even greater reduction. It discusses a wide range of SLCP-reducing activities, including:
JBEI researchers engineer bacterium to produce diesel-range biofuel using CO2 as sole carbon source
July 26, 2013
A team of researchers with the US Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI) has engineered the bacterium Ralstonia eutropha—a microbe now used to produce biodegradable plastic—for the production of fatty acid-derived, diesel-range methyl ketones. A paper on their work is published in the journal Applied and Environmental Microbiology.
R. eutropha is a chemolithoautotroph (an organism that obtains its nutrition through the oxidation of non-organic compounds or other chemical processes) that can grow with organic substrates or H2 and CO2 under aerobic conditions. Under conditions of nutrient imbalance, R. eutropha produces “copious” amounts of polyhydroxybutyrate (PHB). Its ability to utilize CO2 as a sole carbon source renders it an interesting new candidate host for the production of renewable liquid transportation fuels, the team noted in their paper.
EIA: world energy consumption to grow 56% 2010-2040, CO2 up 46%; use of liquid fuels in transportation up 38%
July 25, 2013
|World energy consumption by fuel type, 2010-2040. Source: IEO2013. Click to enlarge.|
The US Energy Information Administration’s (EIA’s) International Energy Outlook 2013 (IEO2013) projects that world energy consumption will grow by 56% between 2010 and 2040, from 524 quadrillion British thermal units (Btu) to 820 quadrillion Btu. Most of this growth will come from non-OECD (non-Organization for Economic Cooperation and Development) countries, where demand is driven by strong population and economic growth; energy intensity improvements moderate this trend
Renewable energy and nuclear power are the world’s fastest-growing energy sources, each increasing 2.5% per year, according to the biennial report. However, fossil fuels continue to supply nearly 80% of world energy use through 2040. Natural gas is the fastest-growing fossil fuel, as global supplies of tight gas, shale gas, and coalbed methane increase. Given current policies and regulations limiting fossil fuel use, worldwide energy-related CO2 emissions rise from about 31 billion metric tons in 2010 to 36 billion metric tons in 2020 and then to 45 billion metric tons in 2040, a 46% increase over the 30-year span.
Researchers propose harvesting CO2 mixing energy to generate electricity
July 23, 2013
Researchers in The Netherlands are proposing a new method for harvesting electricity from CO2 emissions. In a paper in the American Chemical Society’s (ACS’) newly launched journal Environmental Science & Technology Letters, they describe an approach to harvesting the mixing energy from combining the CO2 in combustion gases with air in contact with an aqueous electrolyte.
Mixing the CO2 with air represents a source of energy with a total annual worldwide capacity of 1570 TWh, the researchers calculated—about 400 times the annual output of the Hoover Dam (approx. 4.2 GWh). To harvest the mixing energy from CO2 containing gas emissions, they propose using pairs of porous electrodes, one selective for anions and the other selective to cations.
SAE releases technical white paper on two new low-GWP refrigerants; alternates to R-1234yf
The SAE International MAC (mobile air conditioning) Refrigerant Blend Cooperative Research Program (MRB CRP), comprising a group of leading global vehicle OEMs plus Tier One suppliers, is assessing the operating, technical and safety performance of two low-GWP (global warming potential) blended refrigerants (AC5 and AC6) developed by Mexichem, and based upon R-1234zeE.
The European MAC Directive requires the use of alternative refrigerants with GWP of less than 150 to replace R-134a. The first globally agreed candidate alternative fluid, the hydrofluoro-olefin (HFO) R-1234yf, is now entering production and use after an extensive cooperative research program (CRP-1234) administered by the SAE International and involving global car OEMs and chemical suppliers. (It has also generated some controversy, as Daimler has balked at using it, based on the company’s own testing of flammability. SAE CRP-1234 has re-evaluated the fluid multiple times, and still supports its use.)