Temperature in Nam to rise more than global average

09 August 2021 | Weather

ELLANIE SMIT

WINDHOEK

Temperatures in Namibia are set to rise much more rapidly than the global average.

For each 0.5° C increment in the global temperature, the mean temperature for Namibia will increase by 0.5 to 1° C more.

As the global temperature increases by 1.5° C and more, climate models project that Namibia will experience increasing frequency and intensity of climate extremes, Dr Simon Angombe, the dean of faculty for agriculture and natural resources at the University of Namibia (Unam), said.

He made the remarks during a national dialogue session on the food system in Namibia, which began in preparation of the United Nations (UN) World Food Systems Summit in September.

He made a presentation with regards to climate change adaptation and mitigation strategies and what global warming of 1.5° C and higher means for Namibia.

Angombe said with its dry and hot climate, Namibia is already vulnerable to climate variability, and without adaptation, climate change will heighten this vulnerability.

“For Namibia, local warming and drying will be greater than the global average. So, even a 1.5° C increase in global temperature will have severe local impacts, negatively affecting water supply, agriculture, health, and other vulnerable sectors.”

More heat waves

Angombe said as global and local mean temperature rises, temperature extremes will change as well. Hot days and nights will increase sharply and warm spells and heat waves will also be much more frequent and last for longer.

He added that increasing temperatures will increase heat stress in Namibia’s vulnerable sectors, and will also increase the severity of droughts in the country.

Furthermore, at increasing levels of global warming, total annual rainfall is projected to decrease across the country.

“The largest relative decrease in rainfall will be experienced in the hyper-arid and arid south zones, which will experience decreases of 6% and 7% respectively at 1.5° C.”

It was further explained that temperature increases will lead to an increase in evapotranspiration in Namibia, placing considerable strain on water by reducing soil water, groundwater and surface water availability.

Global temperature increases of 1.5° C and 2° C will result in 10 to 14% more evaporation in the country, with further increases of up to 20% by 3° C.

Meanwhile, surface run-off will decrease by approximately 19% and 30% at 1.5 and 2° C respectively.

Extremely vulnerable

Angombe added that Namibia’s agricultural sector is extremely vulnerable to the impacts of 1.5° C warming and higher.

He noted that the prolonged drought conditions in 2018 - for example - led to the death of 300 cattle and relocation of 17 000 animals in the Omaheke area in the arid north.

He said it is expected that land in the arid south will lose as much as 15% of its carrying capacity for livestock at 1.5° C.

Crop productivity is expected to drop by five to 10% at 1.5° C and 2° C, with a decrease of 20% at 3° C.

“This loss will be even larger for subsistence farmers, with expected decreases of 20 to 80% between 1.5° C and 3° C.

He further noted that livestock productivity is expected to drop by five to 20% at 1.5° C and 2° C, with further decreases of 50% at 3° C.