Frequently Asked Questions

  1. Why do we need CHANGER?

    2. In accordance with international environmental commitments pursuant to the United Nations Framework Convention on Climate Change (UNFCCC), governments will be increasingly required to submit regular greenhouse gas emissions accounts. CHANGER provides a unique opportunity for road construction companies to act both responsibly and proactively by constituting their own greenhouse gas inventories in advance of mandatory national regulations.

    An additional advantage of thinking ahead and taking foresighted steps to reduce emissions is that more and more international financial institutions are progressively including compulsory GHG emissions assessments of road construction projects in their tendering procedures.

  2. What OS does CHANGER support?

    3. CHANGER can be installed in computers running Windows XP, Vista and Windows 7.

  3. What are Greenhouse gases?

    4. Greenhouse gases are gases in the atmosphere that absorb and emit radiations within the thermal infrared range. This causes the so-called greenhouse effect that is contributing to the increase in Earth's temperature. Most greenhouse gases have both natural and man-made sources. Mainly the burning of fossil fuels (mainly solid fuel, liquid fuel, gaseous fuels) has increased the amount of greenhouse gases (mainly CO2) in the atmosphere.

  4. What does CO2 equivalent stand for?

    5. CO2 equivalent is a universal unit for comparing emissions of different greenhouse gases expressed in terms of the global warming potential (GWP) of one unit of carbon dioxide.

    A simple calculation methodology has been developed by the IPCC and is widely accepted in order to compare the contribution of the gases to global warming. The values attributed to the gases are updated periodically.

    For example, the GWP for methane over 100 years is 25 and for nitrous oxide 298. This means that emissions of 1 million metric tonnes of methane and nitrous oxide respectively is equivalent to emissions of 25 and 298 million metric tonnes of carbon dioxide.

  5. What is the Kyoto Protocol?

    6. The UN Framework Convention on Climate Change (UNFCC) aims at stabilizing greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. It had no mandatory limits on greenhouse gas emissions for individual nations and contained no enforcement provisions; it is therefore considered legally non-binding. Rather, the treaty included provisions for updates Protocols that would set mandatory emission limits. The principal update is the Kyoto Protocol. Adopted in Kyoto, Japan on 11 December 1997, the Protocol came into force on 16 February 2005.

    Under Kyoto, industrialized countries agreed to reduce their collective GHG emissions by 5.2% compared to the year 1990 by 2012. Under the Protocol, industrialized countries have stricter binding GHG reduction targets, owing to the Protocol's "principle of differentiated responsibilities", recognizing that the industrialized countries are more responsible for current GHG levels.

    Signatories to the UNFCCC are split into three groups:

    • Annex I countries (industrialized countries)
    • Annex II countries (developed countries which pay for costs of developing countries)
    • Developing countries.  

    The Kyoto Protocol offers three market-based mechanisms for countries to meet their GHG targets: emissions trading in the carbon market, the clean development mechanism, and joint implementation. These mechanisms are meant to be combined with national measures in order to achieve a worldwide 5% decrease from 1990 GHG levels by 2012.

  6. What does embodied energy mean?

    7. Embodied energy is defined as the total primary energy consumed during resource extraction, transportation, manufacturing and fabrication of a product. Typically embodied energy is separate from operational impacts. It has become common practice to specify the embodied energy as “Cradle-to-Gate”, which includes all energy (in primary form) until the product leaves the factory gate. The final boundary condition is “Cradle-toSite”, which includes all the energy consumed until the product has reached the point of use.

  7. What are emissions standards and how are they determined?

    8. Emissions standards are requirements establishing specific limits of pollutants that can be released into the environment. Many emissions standards focus on regulating pollutants released by mobile sources such as automobiles (motor cars) and other powered vehicles but they can also regulate emissions from fixed sources such as industry, power plants, small equipment such as lawn mowers and diesel generators.

    Standards generally regulate the emissions of nitrogen oxides (NOx), sulfur oxides, particulate matter (PM) or soot, carbon monoxide (CO), or volatile hydrocarbons (see carbon dioxide equivalent).

  8. What are Greenhouse Gas Inventories?

    9. A greenhouse gas inventory is an accounting of the amount of greenhouse gases emitted to or removed from the atmosphere over a specific period of time (e.g., one year). A greenhouse gas inventory also provides information on the activities that cause emissions and removals, as well as background on the methods used to make the calculations. Policy makers use greenhouse gas inventories to track emission trends, develop strategies and policies and assess progress. Scientists use greenhouse gas inventories as inputs to atmospheric and economic models.

  9. Are there any known challenges or limitations in this current version of CHANGER?

    a. Pre-Construction Module

    In the “clearing and piling” sub-section the calculation is based on emissions produced by the transportation of removed trees. The tool does not account for either the loss of CO2 absorption by the removed trees or for their replacement with new or replanted trees in the areas concerned.

    In the "Cut transport and Fill transport" sub-section, we have not included CO2 equivalent emissions for machine use such as the use of compactors within the road site. In this section (also pertains to "Materials transportation" of the Pavement Module), we have included eight possible choices for transportation mode. The CO2 equivalent emissions for the eight transportation modes are based on data obtained from the EPE/ADEME October 2005 study (Module GES Transports - Calcul des emissions).

    b. Pavement Module

    Sub-section "On-site impacts". Fuel densities do not have a fixed value, but rather an interval dependent on various factors. For the purpose of the calculator we have fixed the density values of each fuel type to 0.83, 0.509, 0.755 based on the 2003 "Evaluation of the comparative energy, global warming, and socio-economic costs and benefits of biodiesel" study for DEFRA by ND Mortimer (2003) using these values to calculate CO2 equivalent emissions for the fuel type. For the density of biodiesel, the value of 0.83 has been set.

    Section Construction materials, "Material transportation" sub-section: We calculate just the emissions regarding the transportation of the materials from these locations to the road site.