Notes: [1] Natural emissions of methyl chloride and methyl bromide account for around 30 per cent of the total loadings.
Estimates have been revised back to 1995. Data for 1994 and earlier may therefore not be exactly comparable with more recent estimates.
Estimates have been revised back to 1995. Data for 1994 and earlier may therefore not be exactly comparable with more recent estimates.
| Chlorine loadings from ozone depletors | |
| Change since | |
 |
1970 |
 |
1990 |
 |
1998 |
Coverage: Northern Hemisphere
Source: Defra, Meteorological Office
| Ozone levels | |
| Change since | |
 |
1970 |
|
1990 |
|
1998 |
Source: Meteorological Office
- The chlorine loading in the stratosphere more than doubled from 1974 to a peak in 1994. It then started to decline.
- Column ozone measurements in the UK have fluctuated, but have generally decreased since the early 1980s. It appears that this trend may have levelled off in recent years.