Carbon dioxide emissions estimates methodology

Since SEEN initiated this series of reports in 1997, international financial institutions (IFIs) have responded with various criticisms (see responses pages: http://www.seen.org/pages/ftr/watsnlt.shtml, http://www.seen.org/pages/ftr/chinawblet.shtml
http://www.seen.org/pages/ftr/20011018_bondwb.shtml),
none of which raised serious critiques of our actual method of calculating carbon dioxide emissions from fossil fuel-related projects. Rather, most institutions have argued that only on-site emissions should be calculated; that is, they have argued that the ultimate consumption of coal, oil or gas from mines and fields that they support should not be attributed to their institutions. We strongly disagree. This on-line database therefore follows the same methodology that we have used in prior reports.

The following explains our basic methodology for attributing carbon dioxide emissions to projects. Specifics of certain projects require some variation from this methodology, which is explained in those projects’ database records.

Note: The SEEN database calculates emissions estimates of carbon dioxide. Many other sources calculate “carbon equivalent” emissions. Carbon comprises 12/44 of the mass of carbon dioxide; thus to convert from CO-2 equivalent to C equivalent, one multiplies by 0.2727. Conversely, to
convert carbon equivalents to carbon dioxide, multiply the carbon equivalent by 3.67. In 2000, the most recent year for which data are available, worldwide carbon equivalent emissions from fossil fuel use and venting to the atmosphere totaled 6.44 billion tons. This is the equivalent of 23.6 billion tons of carbon dioxide. See the U.S. Energy Information Administration website for a useful list of links to recent estimates of carbon equivalent emissions. Also see the U.S. Environmental Protection Agency website for further explanation of the relationship of carbon to carbon dioxide.

Power plant emissions

The burning of carbon-laden fuels releases a known quantity of carbon dioxide (CO2). Carbon dioxide is not removed from the smokestacks. If a new or refurbished power plant’s capacity and projected lifetime are known, then a prediction of the project’s lifetime emissions is a plain calculation.

For each power plant project, unless otherwise specified, it is assumed that it will run for 20 years at full capacity from the time of financing.

Environmental Costs of Electricity, a book by the Pace University Center for Environmental and Legal Studies (Oceana Publications, 1990), summarizes rates of carbon dioxide and other emissions from various power plants. Table 2 in Chapter IV of the book, "New Coal Plant Emissions," summarizes studies by PLC Inc. and the Oak Ridge National Laboratories for the U.S. Department of Energy.

Coal

According to these studies, a new coal fired power plant will release between 1.96 (PLC) and 2.09 (DOE) pounds of CO2 per kilowatt hour of operation. For our report, we assume that any given coal-fired power plant will emit 2 pounds of CO2 per kilowatt hour.

A power plant with a one megawatt (1,000 kilowatts) name plate capacity will produce the equivalent of 8,760,000 kilowatt hours annually at full operation -- that is, 8,760 hours multiplied by 1,000. At this rate, such a plant would emit an estimated 17,520,000 pounds, which is the equivalent of 8,760 short tons or 7,947 metric tons of CO2.

Natural Gas

Pace's table 3, "Emissions for Natural Gas-Fired Generation," puts the rate of emissions for these type of plants at 1.14 pounds (PLC) and 0.99 pounds (DOE) of CO2

per kilowatt hour. For this study, we assume that 1 pound of CO2 will be released per kilowatt hour; that is, a plant with 1 megawatt capacity will release 8.76 million pounds per year -- 4,380 short tons / 3,973 metric tons.

Oil

Pace's table 4, "Emissions for Oil-Fired Generation," puts the rate of emissions for oil-fired plants at 1.65 (DOE) to 1.75 (PLC) pounds of CO2 per kilowatt hour. For this study, we assume that 1.7 pounds of CO2 will be released per kilowatt hour, or the equivalent of 7,446 short tons / 6,754 metric tons of CO2 per year per megawatt.

This table also summarizes the PLC-determined rate of emissions from diesel-fired plants: 2.19 pounds of CO2 per kilowatt hour, the equivalent of 9,592 short tons / 8,702 metric tons of CO2.

Multiplying these rates' emissions by the assumed 20 years of operation at full capacity, the following conversion rates are used to determine estimated total emissions of World Bank-financed power plants:

Estimated CO₂ emissions per megawatt capacity of World Bank-financed power plants over 20 years of full capacity operations:

Coal Natural Gas Oil Diesel

CO2(in metric tons) 159,968 79,484 135,118 174,061

Fossil Fuel Extraction and Distribution

The study takes the admittedly simplified approach that all fossil fuels extracted and/or distributed will be burned in power plants. We also assume that all proved reserves in fossil fuel fields that are touched by Bank programs ultimately will be burned. Other than power plants, potential demand points for fossil fuels include industrial processes, vehicles, household stoves and heaters. Rates of emission are generally comparable across demand or transformation points, although vehicles tend to emit a bit less CO2 than power plants.

Counterbalancing this approach, however, are numerous omissions from our report. This study does not take into account numerous other likely releases of greenhouse gases due to the extraction and distribution of fossil fuels, such as natural gas flaring from oil field production, methane releases from coal mining or gas exploration operations, and pipeline leaks. We do not attempt to estimate releases of perfluoromethanes, hydrofluorocarbons, nitrous oxide, or other very potent greenhouse gases. Nor do we catalog IFI involvement in numerous other industries -- particularly transportation and cement, aluminum and steel factories -- which are major greenhouse gas emitters.

Therefore, overall, this database might greatly underestimate the greenhouse gas emissions that IFI projects ultimately will help to create.

When an IFI finances a pipeline, we have attempted to identify the source fields for the pipelines, and the total proved reserves of these source fields, which form the basis for our estimates. If we do not know the reserves, but do know the anticipated flow rate through a given pipeline project, we assume that this rate will continue for 20 years.

In 1993, the Stockholm Institute - Boston Center produced "Towards a Fossil Free Energy Future: A Technical Analysis for Greenpeace International." In this report, the Stockholm Institute summarizes greenhouse gas emissions from various sources. It lists emission factors of 2.71 kilograms of CO2 per kilogram of coal input, 1.85 kg per cubic meter of natural gas, and between 3.06 and 3.14 kilograms per kilogram of oil. We split the difference and assume 3.1 kilograms of CO2 emissions per kilogram of oil input.

Thus, we use emission rates of 3.1 metric tons of CO2 per ton of oil, 2.71 tons per ton of coal, and 1.85 kilograms per cubic meter of gas.

For oil, a conversion rate of 7.3 barrels per metric ton is used. For natural gas, the conversion rate is 35.314 cubic feet per cubic meter. One metric ton of gas equals about 138 cubic feet or 3.908 cubic meters. Carbon coefficient for liquefied petroleum gas (LPG), according to http://www.natenergy.org.uk/convert, is 1 liter of LPG : 1.51 kilograms CO-2. A standard oil industry conversion for LPG (at 86-degrees F) is 1,835 liters per metric ton. (See
http://www.nepo.go.th/ref/UNIT-OIL.html).

When we attribute summary emissions to a particular IFI, we try to prevent double-counting of emissions that may occur when a power plant burns fossil fuels that have been extracted or distributed with involvement by the same IFI. For example, estimated emissions from World Bank-financed coal-fired power plants in India that will or might burn coal from mines also financed by the Bank are not included in the grand total of estimated Bank-financed emissions. Similar double-counting prevention procedures are used in pipeline, refinery, and other projects.