The 2016-17 farming season is shaping up to deliver a roller-coaster from strong El Niño to La Niña
Jeffrey Gogo Climate Story
ZIMBABWEAN farmers, facing some of the greatest climate risks in Africa, can look forward to more rain in the summer — hoping that will help boost food production — but no one knows really how widely it will be distributed.
This means some regions could thrive while others starve. Local farmers are still smarting from a bruising 2015 /16 farming season, marked by a serious shortage of rain due to El Nino, with harvests falling by more than half. As a result, more than 4 million people risk going hungry this year, say authorities, who have since appealed to donors for $1,6 billion in aid.
Now, with El Nino — a naturally occurring weather cycle caused by warmer temperatures in the Pacific Ocean — gradually being replaced by its opposite, La Nina, which produces a cooling effect, local climate scientists are predicting more rainfall in the 2016 /17 farming season, but are uncertain over its distribution.
According to Linia Mashawi Gopo, principal meteorologist at the Meteorological Services Department, there are strong signs for higher rainfall this year.
And one of those signs is the unusually cold spells which have swept through the country in recent weeks, with daytime temperatures in Harare dropping to as low as 18 degrees Celsius.
The predictions are premised on an analysis of historical trends following an El Nino year, she cautioned.
Nothing conclusive, as yet, because there are several other factors to consider.
“Research has shown that the prevalence of cool moist south easterlies (wind type) during the winter season is normally associated with a good upcoming rainy season,” Gopo told The Herald Business, by email.
“The relationship is not one to one, however. Most of the years that cool and moist south easterlies prevailed over Zimbabwe during winter, the coming season had good rains (normal to above normal in most cases).”
Rainfall is very important to Zimbabwe. Not only does it define seasons, but nearly three quarters of the 13, 1 million Zimbabweans are dependent on it, through agriculture, says the national statistics agency, ZimStats.
In good times, precipitation averages between 300mm and 1 000mm, with regions in the south-west receiving the least amount of rain, and those in the east along the border with Mozambique, the highest.
However, changes in climates have seen rainfall decline by between 5 and 15 percent countrywide since the 1960s, say experts.
With agriculture accounting for up to a fifth of GDP, and 60 percent of the manufacturing industry raw materials needs, further changes in the climate will hurt Zimbabwe badly.
This is what happened during the 2015/16 summer cropping season, precisely. El Nino, which alters rainfall and temperature patterns worldwide, hit hard, leaving most of Zimbabwe dry, crops failing and forcing a series of heatwaves that saw daytime temperatures breaking 60-year records. Areas like Kariba reported maximum temperatures above 44 degrees Celsius.
Enter La Nina
El Nino’s opposite — La Nina, is now beginning to step in to reverse the damage. The true impact of the cooling phase called La Nina on rainfall will only become clearer in the summer, said Mrs Gopo, but current wind patterns, yielding the frequent unusually chilli days, nights and mornings, are a good indicator.
The Meteorological Services Department’s forecasts will likely deepen the theoretical feud that has long existed between science and indigenous knowledge, as the later tends to associate very cold winters with low rainfall.
Native traditions are currently fighting to find space within the scientific discourse, as tried and tested methods that can be relied upon to provide accurate weather and climate predictions, and to combat climate change.
“Prevalence of cool and moist south easterlies and presence of La Nina all point towards more rainfall over Zimbabwe,” said Mrs Gopo, before warning “but no one knows the distribution, more rainfall might be received with very poor distribution.”
Zimbabwe’s rainfall season lasts up to six months, with the main season occurring between December and February. But the on-set periods, usually occurring around October, are longer certain and dry spells within a single season are becoming frequent due to climate change, according to the Ministry of Environment, Water and Climate.
It is not uncommon for droughts to occur in back to back seasons.
Mrs Gopo is worried that frequent El Nino events will ravage Zimbabwe’s rain fed agriculture in the future.
“As the climate is changing there is significant increase in the global temperatures and research is showing there are high chances of reduced return periods of El Nino and less rainfall over Zimbabwe during most years,” she said.
“El Nino is associated with extremely high temperatures and Zimbabwe has been experiencing less rainfall, longer and more frequent dry spells during the rainfall season.”
New studies suggest that climate change will result in frequent, very strong El Nino events in the future, possibly occurring once every decade. El Nino usually strikes once every 7 years but the most extreme occur in 20 years, say scientists.
These changes, and others, could see Zimbabwe’s production of the maize staple fall by between 30 and 50 percent through 2030, as temperatures soar two degrees Celsius by 2080, according to the UN’s expert panel on climate change.
Probability of years in which growing season is likely to fail in future due to drought is projected to be as high as 100 percent in some parts in the south, says the panel.
With more people in Zimbabwe directly reliant on rain fed agriculture – meaning increased vulnerability to climate extremes like floods, hailstorms and drought — authorities are not leaving anything to chance.
“Climate change adaptation in the agricultural sector is a national priority, demanding policy direction at the highest level,” said the Climate Ministry in its submissions to the UN last September.
The submissions represent Zimbabwe’s contribution to the global efforts of halting climate change’s dangerous impacts.
“Rainfall is, therefore, the most critical climate component for Zimbabwe as already small changes can affect ecosystems, and all key socio-economic sectors,” it said.
God is faithful.