Dealing with Climate change

country soaring to 46 degrees Celsius, pretty extreme than ever in the last half a century.
The country was abuzz with talk over the sweltering heat. “Iyi ndiyo climate change chaiyo,” a young woman remarked fanning himself with a hat in a street in the city centre. But does a mere variation in temperature mean that Zimbabwe is now experiencing climate change?

A workshop held recently on climate change organised by the Community technology Development Trust (a local NGO) was a good one to check on how seasonal climate variations is stacking up against expectations. People’s perception of climate change usually differ from the one held by academics and the scientific community.
To most people, the fact that temperatures hit the 46 degree barrier in Chiredzi and Buffalo Range is a sure indicator of climate change in Zimbabwe.

But for scientists, it is not enough to conclude that Zimbabwe is now experiencing climate change because of this sudden upsurge in temperature.
“An extreme event is sometimes confused with climate change, although there might be some correlations, but this does not necessarily mean a changed climate,” said Tirivanhu Muhwati, a weather expert from the Zimbabwe Meteorological Services Department.
“We should not confuse temperature variations with climate change.”

Climate change, he said, can be described as an identifiable statistical change in the state of the climate which persists for an extended period of time while climate variation referred to variations in the mean state and other statistics relating to the climate on all temporal and spatial scales beyond that of individual weather events.
“For example, Harare has an average mean rainfall of 600mm per year and if this mean falls to 550mm then we can conclude that climate change has taken place. If this mean (600mm) does not change over say a 30-year period, then no climate change has taken place,” the weather expert said.

Muhwati presented statistical figures on rainfall patterns from around the 1900s to 2010 as well as temperature patterns from 1962 to 2008. Zimbabwe is increasingly experiencing temperature changes as a result of global warming or global climate disruption, as some meteorologists would argue.
The Zimbabwe average minimum temperatures increased from 13 degrees Celsius in 1962 to 14 degrees Celsius by 2008 while average maximum temperatures went up from 26 degrees Celsius in 1962 to 27,2 degrees Celsius by 2008.

“Debate is healthy as it helps us to do better analysis. The temperature data base goes back to 1962. Zimbabwe is experiencing a gradual increase in temperatures – year to year variability. It’s showing an increasing trend,” he said.
“One of the most contentious issues in the climate change debate is attribution. We need to prove that climate change is really taking place. The link is very difficult to explain. What evidence do you have that warming is causing a decrease in rainfall. This is what climate skeptics normally ask us.”

A University of Zimbabwe – CTDT study report on the perception of smallholder farmers from UMP, Murehwa, Chiredzi and Tsholotsho of climate change indicated that the most prominent feature they identified as a sign of climate change included rainfall distribution – change in rainfall patterns in the last 30 years, changes in temperature, changes in forest vegetation, recurrent droughts and very high ambient temperature, drying up of water sources, warm winter season and the extension of the winter season.

“This is how they perceive climate change to be taking place. We had to conduct research to verify their perceptions with data on climate change from the Met Office,” said Dr Emmanuel Mashonjowa of the UZ Agri-Meteorology Department.
“In all districts, farmers stated that rainfall amounts, and distribution, have changed in the past ten years. They say there has been a general decline in the rainfall amounts, recurrent droughts, drastic changes in the rainfall distribution – delayed onset dates of the rainy season and increased frequency and length of mid-season dry spells.”

Farmers, he also said, stated that the climate had become warmer in recent years with higher than normal day time temperatures, warm nights and warm winter seasons.

“Farmers’ perceptions of climate change generally agree with findings of analyses of rainfall and temperature data. These show that in the last 20-30 years, there has been an increase in rainfall variability and frequency and severity of droughts,” Dr Mashonjowa said.

Generally, according to the UZ-CTDT study, there was an observed delay in the onset dates of the rainy season in Chiredzi and UMP, shortening of the length of the growing period in these districts something that tallied with farmers’ perceptions. Findings also suggest that there was general warming of temperatures in all the three districts by about 0,3 to 0,4 Degrees Celsius and that most of the warming occurred during the period after 1980 – the period with higher than usual occurrences of droughts.