§ Norman BakerTo ask the Secretary of State for Environment, Food and Rural Affairs what change there has been in the percentage of ice cap cover in(a) Antarctica and (b) the Arctic in each year since 1974; and what total (i) area and (ii) volume the change between 1974 and 2003 represents. [165747]
§ Mr. MorleyThe following tables show
Percentage change in sea ice area for the southern and northern hemispheres from 1975 to 2003, relative to 1974.Change in sea ice area in million square kilometers for the southern and northern hemispheres from 1975 to 2003, relative to 1974.There is no significant trend in area coverage of Antarctic sea ice. Arctic sea ice shows a downward trend of approximately 2.9 per cent. per decade.
Observations of ice thickness are not routinely available, and consequently it is not possible to construct a description of the annual volume change. From the limited data available there are indications that there is a downward trend in Arctic sea ice volume of 4 per cent. per decade.
Graphs showing the change in sea ice area have been placed in the Library of the House. Note that reliable satellite measurements of sea ice area have been available only since 1978. The apparent rapid change in sea ice in the 1970s is partly due to the change from the previous sparse ship observations to the routine satellite measurements.
145W
Percentage change in sea ice area relative to 1974 Year Antarctica Arctic 1975 -4.2 -0.6 1976 -8.9 1.2 1977 -11.2 0.3 1978 -8.9 1.1 1979 -8.6 -1.9 1980 -12.3 -2.2 1981 -10.4 -4.6 1982 -8.5 -1.1 1983 -11.1 -2.5 1984 -9.6 -5.8 1985 -8.4 -5 1986 -13.7 -3 1987 -10.1 -2.6 1988 -9 -3.3 1989 -9.8 -4.9 1990 -9.4 -7.5 1991 -9.5 -6.5 1992 -10.6 -3.7 1993 -9.9 -6 1994 -6 -4.2
Percentage change in sea ice area relative to 1974 Year Antarctica Arctic 1995 -69 -9.9 1996 -74 -6.3 1997 -8.5 -5.3 1998 -6.9 -4.5 1999 -7.9 -4.1 2000 -6.7 -6.6 2001 -8.9 -5.1 2002 -1.6 -6.7 2003 -5.9 -6.9
Absolute change in sea ice area (million square km) relative to 1974 Year Antarctica Arctic 1975 -0.432 -0.06 1976 -0.915 0.14 1977 -1.154 0.04 1978 -0.911 0.13 1979 -0.882 -0.21 1980 -1.268 -0.26 1981 -1.07 -0.53 1982 -0.868 -0.13 1983 -1.145 -0.29 1984 -0.991 -0.66 1985 -0.865 -0.57 1986 -1.408 -0.35 1987 -1.042 -0.3 1988 -0.928 -0.37 1989 -1.005 -0.57 1990 -0.971 -0.86 1991 -0.977 -0.74 1992 -1.085 -0.43 1993 -1.015 -0.68 1994 -0.618 -0.48 1995 -0.707 -1.14 1996 -0.765 -0.72 1997 -0.869 -0.61 1998 -0.714 -0.51 1999 -0.815 -0.47 2000 -0.684 -0.75 2001 -0.91 -0.58 2002 -1.192 -0.76 2003 -0.604 -0.79