HEATWAVE: CLIMATE CHANGE OR VARIABILITY:
THE weather presenter on ZTV Sanduro Chirambaguwa points to a map showing little bright-yellow shining stars, warns of impending searing heat, before cutting away to an image that lists areas like Kariba and Victoria Falls as the face of last week’s heatwave.
In just about two minutes Chirambaguwa’s job is done, but her warnings will live long. The Meteorological Services Department (MSD) has often elicited derision mostly from farmers for alleged inaccurate predictions, but few would disbelieve when everyday TV weather commentary becomes a lived experience.
For the second time in two years, Zimbabwe has been hit by a wave of heat of near record-breaking scale, and yet, climate change sceptics are still non the wiser. Indeed, the deniers may be farafield like Donald Trump, but even local meteorologists have urged caution against linking every little weather calamity to climate change, with good reason.
Met Department forecaster James Ngoma had earlier that night told the ZTV news crew how above 40 degrees Celsius temperature spelled doom for human health, though he vacillated around the issue of linking the soaring temperatures as absolute evidence of global warming and climate change on the domestic front.
Instead, he preferred more nuanced responses that left conclusions to conjecture, gyrating between climate variability and climate change. Eventually the people had their own verdict, as demonstrated by the inescapable heat of the past week.
It is understandable why meteorologists almost always employ caution on climate change issues. Why communities tend to distrust information from the MSD say on rainfall patterns (University of Zimbabwe research shows small-farmers are generally apprehensive of scientific forecasting) unless those predictions are immediately impactful, it’s something else.
Regardless, the connection between weather and climate is becoming all too clear that it’s become almost impossible to separate climate change impacts from everyday weather. Experts say while weather forecasters and climate scientists focus on different time scales, they rely on similar data and computer models, with both sides seeing marked improvement in predictive accuracy in recent years.
The successive year after year extreme events, from too much heat to drought, excessive cold to flooding indicate some of the most pressing issues in post-independent Zimbabwe. The drought of 2015/2016, forced on by El Nino, was recorded as the country’s worst in a quarter Century; 2016 has been reported the hottest year in recent memory, as floods rammed through cities and villages in 2017 picking up an above $500 million tab in damaged infrastructure.
As the Meteorological Services Department’s Ngoma said on TV and in the Press, temperatures have set new records in 2017 in some areas, with Kariba peaking at 45 degrees Celsius, and Nyanga, often the low temperature zone, tipping the thermometer at 38 degrees Celsius. Gwanda, Beitbridge, Chiredzi and Victoria Falls all measured above 40 degrees Celsius.
It is difficult to reconcile whether all these events result from climate change or everyday changes in the weather. Speaking on the same ZTV news bulletin, Shepherd Zvigadza, who heads the nonprofit environment organisation ZERO, said it was premature to link the temperature spike to climate change, even though scientists have gathered evidence the heat was a tell-tale sign of global warming.
In 2007, the UN panel on climate change, the most authoritative body on the science, found that it was very likely that cold days, cold nights and frosts have become less frequent across Africa, while hot days and hot nights have become more frequent due to climate change. It said heatwaves had also increased in frequency while heavy precipitation events (or proportion of total rainfall from heavy falls) has increased over most areas.
And climate scientists point to several ways in which global warming may already be exacerbating heatwaves, drought or floods. James Ngoma, the Met Department forecaster, said that last week’s heatwave emanated from the “northerly air flow” from around the equator region, but one that brings with it no rain. So, what you get is very hot air in dry conditions, and nobody wants that.
Secondly, massive deforestation and rapid urban development, often times poorly planned, have created a conducive atmosphere for waves of heat. University of Zimbabwe climate change researcher Terrence Mushore has found that more cities and towns will become very hot in 25 years, as a result.
He has researched how areas with day-time temperatures ranging between 36ºC and 46ºC will expand to cover about two thirds of urban areas, while those averaging 18ºC to 30ºC decline. In Harare, for example, Mushore found that more than 75 percent of vegetation - those areas under trees, wetlands grass etc, which are key to maintaining the temperature balance - was decimated between 1984 and 2016 as high density areas expanded by 92 percent.
As a result temperatures have climbed between 0,98ºC and 1,98ºC in the 30 years to 2015 as the swelling number of people moving into the city fed into the urban development cycle that fans deforestation. Countrywide, day-time temperatures have increased by about a Celsius since the early 1900s with marked increase noticed in the period after 1960 according to Zimbabwe’s climate change response strategy. Precipitation has declined by about 5 percent, and as much as 15 percent in other areas, the strategy says.
Scientists have for years tried to bring this message home, about “the difference between these longer-term climate trends and the daily weather.” They want people to understand how Sanduro Chrimbaguwa’s two-minute weather report about the heatwave represents weather for a specific day or period (like the 3-day heatwave last week), and how it is not necessarily an opposing view to current and future scientific predictions on climate change.
This message might not have found its rightful place yet.
God is faithful.