Calculating carbon emission is the first step in applying a project as a Clean Development Mechanism (CDM) activity to gain carbon credits. Now that CDM activity has taken root in the country (see previous post), a better understanding of the process of calculating carbon emissions is necessary.
It is not only CDM projects that make such calculations. In the never-ending search for energy efficiency and in efforts to combat global warming, companies ranging from multinationals to rural piggeries, have launched programs to limit their greenhouse gas (GHG) emissions to the extent of making their operations carbon neutral.
Also, big sporting events like the World Cup and the recently concluded Beijing Olympics, and large international conferences like the gathering of G8 leaders in Japan, have been under severe pressures to limit their GHG emissions and minimize their environmental impacts.
Organizers and environmental critics would dearly love to see these events becoming carbon neutral.
SAS, an IT vendor for business intelligence, sensing an upcoming opportunity, has already introduced into the country a carbon calculator, a software that determines a company’s or an event’s carbon footprint.
The first step in hosting a carbon neutral event—say, a conference--is quantifying how much GHG emissions the event would likely generate. The emissions assessment should cover not only during the event itself, but throughout-- from planning, to calculating the two-way travel emissions by the participants, to recycling of materials at the end of the show.
To do this, one should calculate the total carbon emission or footprint of the event using a carbon calculator.
Existing carbon calculators range from order-of-magnitude estimates to fairly sophisticated devices that detail every possible source of emission and the methods backed up by reputable data. There are free carbon calculators usually offered by non-governmental organizations concerned with global warming and government institutions such as the US Environmental Protection Agency (EPA) and there are sophisticated commercial calculators used by carbon market traders, renewable energy project developers applying for carbon credits through the Clean Development Mechanism (CDM) developers, and big business carrying out a corporate program towards carbon neutrality.
Outputs also vary greatly in accuracy depending on the type of event or project being considered, on the assumptions and data used by the calculator developer and on the geographical area where the calculator is to be used.
There are activities or projects such as aviation travel or driving a car to a given distance, wherein the carbon footprint can be calculated with reasonable accuracy. At the other extreme, there are projects wherein the calculations border on faith and questionable assumptions. These include biomass burning, reforestation and carbon sequestration by soils.
In order for offsetting to be credible, the GHG emission has to be calculated accurately. Therefore, the most important consideration is to choose carefully the carbon calculator to be used.
Let us take a fairly simple example relevant to carbon neutral conferences: aviation travel. Jardine (2005, p.2) presented a detailed presentation on how aviation emission per individual is calculated.
The major assumptions in the calculation include the knowledge of the amount of fuel during the flight, the distance traveled, cruising altitude, weather conditions, the passenger and cargo load, the likely aircraft type used, etc. Even if these are accurately known, one cannot simply arrive at a general impact value per passenger.
For example, flight distance does not scale linearly because one has to consider the extra burn required during take-off and landing. Needless to say, direct flight is far more efficient than one with a stop-over.
Different types of aircraft burn fuel at different amount; therefore in Jardine’s (2005, p.3) study, three most likely aircraft types were considered: Boeing 737 for short-haul and Boeing 747 and Airbus 320A for medium and long-haul.
After the emission is determined, the global warming impact has to be determined using a chosen metric. In aviation, the usual metric is radiative forcing which is defined as “the change in the energy balance of the lower atmosphere by a climate change mechanism” and is measured in units of Watts per square meter (W/m2). The ‘climate change mechanism’ is typically the emission of a greenhouse gas (e.g. CO2 from human activity), or a collection of different gases (e.g. all greenhouse gases from the agricultural sector).
Despite a well defined boundaries or conditions for the calculations, different calculators give different answers. For example, six different calculators gave values ranging from 2 to 6 tons CO2 tons for a 17,900 km flight.
The differences in the estimates arise from: (a) whether only CO2 or all GHG gases are considered, (b) including or not non-gas components that could affect the metric used; and (c) setting the boundaries for the calculation—that is, whether the portion of airport services is considered or not.
It is preferable to choose a calculator which is most comprehensive in its calculation.
It is also crucial to choose a provider accredited with a top accepted standard to ensure getting a comprehensive calculator. Some of the stringent standards include the Gold Standard, the Greenhouse Gases Protocol, the International Organization for Standardization (ISO) ISO14064, The Voluntary Carbon Standard (VCS) and The Climate, Community and Biodiversity Standards (CCBS).
After going through the rigors of understanding and choosing the most appropriate carbon calculator, one is now poised to offset his event’s carbon emissions.
Reference:
Jardine, C.N. (2005). Calculating the environmental input of aviation emission, 14. Retrieved August 18, 2008 from http://www.climatecare.org/media/documents/pdf/ Aviation_Emissions_&_Offsets.pdf
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Note added, November 18, 2008: On Thursday this week President Gloria Macapagal-Arroyo will preside over an important conference billed Carbon-Cutting Congress vs. Climate Change which will showcase this adminstration's "Green Philippines" program. This program should start calculating the emissions of the 54 congressmen and the whole entourage who will be going to Peru with GMA using the procedure above if Congress is serious about its green program. The gentlemen and ladies will be in for a shock at the number that will be arrived at.
