Climate Change and Ozone Depletion

• Total emissions of carbon dioxide (a major greenhouse gas) from the burning of fossil fuels in the Yukon were 440,000 tonnes in 1993 - 49 per cent of this was from transportation.

• World-wide average temperatures are increasing. Summer temperatures in the Yukon and northern BC show a slight, but statistically significant, increase since the beginning of the century. The growing season at Mayo has become warmer. Winter temperatures are more variable and show no clear trend. Warmer summers may be due to natural variations in climate or may be associated with global warming from increased greenhouse gases.

• Since the late 1970s stratospheric ozone thickness has declined. Because the angle of the sun is low at high latitudes, ultraviolet radiation reaching the Yukon due to ozone depletion has probably been small.