Significant changes in Zim climate over 100 yrs
Climate in Zimbabwe has changed significantly in the past 100 years and some of the key findings by the Met Office indicate that:
Annual mean temperature for Zimbabwe has increased by about 0,4 degrees Celsius between 1900 and 2000
- The country has experienced a rise in daily minimum temperatures of around 2,6 degrees Celsius in a century
A rise in daily maximum temperature of about 2 degrees Celsius per century
- Number of cold days is decreasing at the rate of about 14, 17 and 16 days per 100 years
- The number of days with minimum temperatures below 12 degrees Celsius have decreased between 1950 and 1990
- Number of days with maximum temperatures equal to or above 30 degrees Celsius have also increased between 1950 and 1990.
- Rainfall data shows no consistent trend indicating that changes in temperature and weather patterns were affecting the frequency and severity of rainfall, droughts, floods, access to water and the use of land.
According to the Met Office, rainfall has declined by about 5 percent and rainfall events have become more intense while mid-season dry spells have increased.
Extreme events are becoming more intense and of longer duration coupled with periodic shift in onset of rains.
Zimbabwe has experienced six warmest years on record since 1987 and an increase in the frequency of droughts since 1990 (90/91, 91/92, 92/93, 93/94, 94/95, 97/98, 01/02, 02/03, 04/05, 06/07) leading to massive drop in crop yields in the country’s agricultural sector.
The country is also experiencing an increase in the frequency of floods.
It has experienced cyclone-induced flooding, which included Cyclone Bonita (1996), Eline (2000), Japhet (2003) and another in 2007. Future climate change projections for Zimbabwe indicate that the country is warming at the rate of 0,15 to 0,55 degrees Celsius per decade. Annual rainfall is projected to decrease across Zimbabwe.
The Met Office reports that the decrease will occur in all seasons, but will be more conclusive for the early and late rains than for the main rainy season months of December to February.
By 2080, annual rainfall will average 5-18 percent below the 1961-1990 average of 634,8mm.
It is also projected that the frequency and duration of dry spells is likely to increase while extreme climate events such as dry conditions, heat waves and heavy precipitation will become more intense and frequent increasing the risk of droughts and floods.
Southern Africa is likely to experience a temperature rise ranging from 2 to 4 degrees Celsius as a result of doubling carbon dioxide emissions in the next century while precipitation is expected to decrease by 10-15 percent in some areas and increase by similar percentage in others.
The Met Office reports that the frequency and duration of dry spells is likely to increase for the entire sub-region.
Other experts say with predictions that agricultural productivity in Zimbabwe could decrease by up to 30 percent because of increases in climate extremes, climate change poses one of the most serious food security challenges in the 21st century for the country.