Current climate predictions issued by the South African Weather Service for the period February to June 2018 indicate that the El Niño system is expected to remain in a weak La Niña phase through to early Autumn.
This suggests above-normal rainfall is to be expected later in the summer rainfall season, which can extend towards early autumn for the northern and eastern parts of the country. However, this may change as circulation over the equatorial Pacific Ocean does not resemble a typical La Niña phase and creates a bit of uncertainty in the current forecast. Weather predictions are becoming more difficult to predict with fluctuations in temperature and climate change. Lower temperatures on average are expected throughout the autumn period for our region and rainfall is expected to be higher than normal. If predictions are accurate, this is good news for us in the Lowveld.
Comparative rainfall figures for the period 2017/2018 to date (Kingfisherspruit KNP ranger station) are as follows:
|January 60 mm||January 10 mm|
|February 84.1 mm||February 82.2 mm|
|March 36 mm||March 66.3 mm|
|April 79.1 mm|
|May 4.9 mm|
|June 1.7 mm|
|July 0 mm|
|August 1.7 mm|
|September 1.6 mm|
|October 43 mm|
|November 22 mm|
|December 37.5 mm|
|Total 2017: 371.6 mm||Total 2018: 158.5 mm (Jan-March)|
|Long term annual average: 571 mm||Long term annual average: 571 mm|
Although the above figures reflect a higher rainfall average for January-March for 2017, the long-term annual average total figure was very low for that year. This coupled with higher than average daytime temperatures had a significant effect on the ecology of the region.
Climate change, a real threat.
At the end of 2017, we could look back at the statistics and see that globally it was the warmest non-El Niño year on record. In a world that is getting warmer, what does that mean and what might 2018 hold for weather across the country? Are we destined to see more of these unusual weather events and prolonged droughts which have significant consequences for the ecology and our wildlife? What effect will climate change have on our weather systems in the Greater Kruger conservation region and what will possibly become the new norm?
Firstly we need to untangle the difference between weather and climate change. In a nutshell, the difference is time. Weather is the conditions in the atmosphere over a short period of time. Climate is how the atmosphere behaves over a longer period of time. When we talk of climate change, that generally means changes in long-term averages of daily levels of temperature and rainfall. So we may see a change in average or typical weather over a number of years.
According to the Intergovernmental Panel on Climate Change (IPCC – an international body set up to assess the impact and science of climate change), we can continue to expect an increase in the average global temperatures. This means that we will be experiencing warmer than average years in the future, which may have a significant impact on both the ecology and the species diversity in the Lowveld.
At the same time, we may see changes to the extremes, which could become more frequent in the case of high temperatures or possible heavy rainfall, or less frequent in parts. This means that the distribution, occurrence, and expected averages of our weather throughout the coming years may change, resulting in warmer years on average with more extreme hot days, and fewer extreme cold days in future. These patterns have direct links to phenomena such as heat waves caused by extreme temperatures, which link to drought conditions and low-flows in rivers, in addition to having significant and complex effects to water sources.
Recent discussions and research through the IPCC with reference to the South African National Parks (SANParks) reserves in South Africa suggest that a more noticeable spatio-temporal change in the short to medium term seasonal cycles of low-high rainfall, rather than a clear increasing or decreasing trend. This research data also indicates increased rainfall variability within the Greater Kruger conservation areas with increased seasonality with longer, more severe dry periods. It is evident through this research that both high and low rainfall patterns are either lengthening or shortening, and/or shifting outside of recognised wet or dry season windows over the short to medium term. Significantly, the far northwest of the Kruger National Park has undergone significant spatio-temporal rainfall changes in the short-term. This may well be mirrored in the central regions of the Kruger and surrounding reserves in the future.
Temperatures at Skukuza have been monitored since 1960. The last December, January, and March were among the hottest months recorded in the last five decades. Between July 2015 and June 2016, 28 days surpassed the 40⁰C mark. Only eight days were this hot during the 1991 drought in the Kruger.
The first signs and alarm bells started in 2001 when a comprehensive study was done by the South African National Biodiversity Agency. They calculated that temperatures would rise by an average of 3⁰C by mid-century. This could affect certain animal species that would be unable to move ahead of change. The agency predicted and warned that this phenomena could kill of 59% of mammals, 40% of birds, 70% of butterflies, 80% of other invertebrates and 45% of reptiles. This statistic is alarming and extremely worrying. For the Kruger National Park, it means change will come too fast for many species to adapt.