Our contribution starts with reducing the emissions from our facilities that contribute to smog and acid rain – nitrous oxide (NO_x), sulphur dioxide (SO₂) and volatile organic compounds (VOCs). VOC emissions from our operations have dropped more than 50% since 1998 – mainly because we stopped venting associated gas at oil production sites. Our NO_x emissions are also lower, even though we are now using much more energy to refine cleaner fuels. This was due mainly to investments in pollution control equipment, particularly at our Singapore and USA refineries and chemicals plants. SO₂ emissions at our refineries and chemicals plants are also down by almost 10% since 2001. In our upstream business, SO₂ emissions have been rising, mostly because more sour gas (hydrogen sulphide) is being flared in remote locations in Canada and Oman. As a result, Shell’s total SO₂ emissions have risen by 8% since 2001. With our help, people living near some of our sites now take part in monitoring the air quality in their communities.