The ozone layer absorbs harmful ultraviolet-B radiation from the sun. Over the past 30 years ozone levels over parts of Antarctica have dropped by almost 40% during some months and a 'hole' in ozone concentrations is clearly visible in satellite observations.
Ozone is been damaged mainly by:
1. Chlorofluorocarbons (CFCs) that are used in refrigerators, aerosols, and as cleaners in many industries.
2. Halons that are used in fire extinguishers.
3. Aircraft emissions of nitrogen oxides and water vapour.
As Ozone is considered to be a greenhouse gas, a depleted ozone layer may partially dampen the greenhouse effect. This may therefore lead to increased global warming.
Conversely, efforts to tackle ozone depletion may result in increased global warming!
The hydropower-dependent energy sector in Tanzania has been seriously affected by drought. The country is turning to coal and natural gas as new sources of energy.
Some cities in Europe and USA experienced power shortages during summer of 2006 due to effects of increased temperatures (The infrastructures failed to cope with the record heat - unsuitable wires, pipes, etc not designed for higher temperatures).
About 82% of the icecap on mount Kilimanjaro in 1912 is now gone. If recession continues at the present rate, the majority of the mountain glaciers could vanish in the next 15 years.
The area covered by glaciers on the Rwenzori Mountains halved between 1987 and 2003, expected to disappear in the next 20 years.
