1. 030715v1.0GJ Costello GMIT Slide 1 Introduction What’s a tonne of CO 2 ? The Kyoto Protocol is an international agreement to limit greenhouse gas (GHG) emissions. Carbon dioxide (CO 2 ) is the most important GHG. Emissions of CO 2 are normally quoted in tonnes. However, a tonne of CO 2 is difficult to visualise. The next two slides attempts to explain “what a tonne of CO 2 is” in terms taken from everyday experience. The calculations are shown on the last slide. Run the slide show and just use the mouse to transition from slide to slide. If you have any suggestions on improving this presentation please contact mailto:gabrielj.costello@gmit.iemailto:gabrielj.costello@gmit.ie

2. 030715v1.0GJ Costello GMIT Slide 2 What’s a tonne of CO 2 ? 13 bulbs will emit 1 kg of CO 2 in one hour 100W light bulbs => 13,000 bulbs will emit a tonne of CO 2 in one hour

3. 030715v1.0GJ Costello GMIT Slide 3 What’s a tonne of CO 2 ? 2 kg of CO 2 will fill your oil tank (1000L) => 1 tonne will fill 500 oil tanks

4. 030715v1.0GJ Costello GMIT Slide 4 Calculations Electricity generated in Ireland* results in emissions of 776 grams of carbon dioxide (CO 2 ) per kilowatt hour (kWh) i.e. unit of electricity 13 bulbs rated at 100W use 1.3 units in one hour  1.3 x 776g ≈ 1 kg of CO 2 emissions 1 mole of CO 2 occupies a volume of 22.4 litres at S.T.P. 1 mole of CO 2 = 12 + (16x2) = 44 grams (relative molecular mass) 44 g of CO 2 ≡ 22.4 litres at S.T.P.  1 kg of CO 2 occupies approx 500 litres at S.T.P. * Note: This is the figure as of 2001. The carbon factor depends on the primary fuel mix that is utilised to generate the electricity. The carbon factor varies from year-to-year and from country-to-country. e.g. The 2001 carbon factor for the UK was 430 g CO 2 /kWh