Johannesburg - This year is going to be the warmest year ever in terms of the global record, according to a researcher.

"This will be the warmest year measured by humans on the planet," the Council for Scientific and Industrial Research's Dr Francois Engelbrecht told News24 on Thursday. 

He said one of the only things that could prevent warming on this scale was a large volcanic eruption like that of Krakatoa. 

That volcanic eruption in 1883 is often considered to be the loudest sound ever heard in modern human history. Some reports say the sound was heard nearly 5 000km away. 

He said the ash cloud from a eruption on that scale would have sulphur dioxide, which would reflect some sunlight back into space. 

"But that is just an example of how warm this year is."

Global warming, El Nino

He said this global increase in temperature was caused by global warming and the El Nino phenomenon. 

El Nino is the warming of the Pacific Ocean from its normal temperatures, which often result in severe weather conditions. 

"Every 2 to 7 years the Pacific Ocean warms up. We are in such an event now, and the ocean temperatures are warmer than normal," Engelbrecht said. 

"The event is expected to intensify further and peak in December."

Usually when the global record increases it is by 0.01%. This year it is expected to go beyond 0.1%. 

"That is 10 times higher than what is normal."

In South Africa, the year has been above normal across the country, he said.

Over the Highveld, the first nine months of the year were the warmest on record. Over the other parts of the country the levels were above normal. 

"This coming summer is going to be a warm summer over SA. It is also a season of below normal rainfall," Engelbrecht said.

"We are already in a state of drought at the moment - parts of the Western Cape, Mpumalanga and Limpopo, North West and the Free State are already experiencing severe drought."

Low rainfall

He said the last two summer rainfall seasons had below normal rainfall, and having another season with below normal rainfall will make the situation worse. 

Engelbrecht said one of the important things we needed to think about was the effect on the country's agriculture. 

"SA farmers are used to a high degree of climate variability. It is not the first time they have faced El Nino, and they have to make certain decisions."

He said farmers could be more conservative with planting seeds so that if there was a problem with the below normal rainfall, their financial losses would be less. 

Meteorologist Simon Gear told News24 said there should have been regular thunderstorms, but there was only one last week and nothing forecast. 

"Dams are at about 55% in Gauteng, where as this time last year they were around 80%," he said. 

"The forecast is a long, hot, dry summer." 

He said it was possible this could be one of the hottest years on record, but "we still have to see". 

Gear said if people stopped watering their gardens and lawns, that would reduce water usage to about 50%. 

And if things got worse there could be "hectic" water restrictions. 

He also said the conditions are caused by a combination of factors including El Nino and global warming. 

"With this we can see what the future holds."

News24