File photo: Greenpeace Africa activists used three dumper trucks to unload five tons of coal in front of the Eskom Megawatt Park offices. Picture: Antoine de Ras

Durban - The volume of South Africa’s climate-warming gases has surged by nearly 25 percent over the past 10 years, despite warnings that all countries need to reduce emissions drastically to avoid dangerous alterations to the world’s climate patterns.

The latest greenhouse gas (GHG) inventory suggests that national emissions reached a record level of 579 256 gigagrams (CO2 equivalents) in 2010, an increase of 24.9 percent compared with emission levels in 2000.

The majority of this cloud of climate-altering gases came from emissions from Eskom coal-fired power stations, along with energy-intensive industries such as Sasol, an increasing level of exhaust fumes from trucks and cars, or methane emissions from burping cattle.

While the total volume of greenhouse emissions attributed to residential home use was reported to have surged by almost 250 percent over this 10-year period, emissions from home electricity use appear to account for only 3.5 percent of total energy-related emissions.

Overall, energy-related emissions made up 85 percent of the country’s overall emissions, with farming and forestry-related emissions (about 8 percent), manufacturing industries (around 5 percent) waste and sewage disposal (about 2 percent).

In the farming sector, total emissions declined by about 7 percent over the 10-year period, but still produced very significant methane emissions from “enteric fermentation” and manure from livestock.

Enteric fermentation refers to gaseous emissions from livestock, mainly methane belched out by beef and dairy cattle during the digestion process, along with a “small quantity of flatus (farting)”. Cattle were estimated to contribute about 81 percent of these fermentation emissions, with smaller contributions from sheep, goats, horses and pigs.

The emission estimates are based on a total cattle population of around 12 million, but no estimates are provided for methane emissions from South Africa’s human population of 51 million.

However, emissions from the waste sector (mainly rotting garbage sent to municipal dumps and rotting human and industrial sewage in wastewater treatment plants) had increased by almost 60 percent between 2000 and 2010 (accounting for almost 3 percent of overall emissions).

Jongikhaya Witi and Luanne Stevens, the main authors of the GHG inventory on behalf of the Department of Environmental Affairs, acknowledged that there was still a lack of reliable data about several emission sources, including leaking gases from oil and gas industry operations, leaks from abandoned coal mines or emissions from the soil and rotting leaf matter across the country.

l At a global level, the UN Intergovernmental Panel on Climate Change (IPCC) estimates that about 50 percent of all human-induced greenhouse emissions since 1750 have been generated in the past 40 years.

A series of recent expert reports released by the IPCC suggest that carbon dioxide and other greenhouse gases in the world’s atmosphere have reached the highest level in 800 000 years, and that human-induced emissions are the dominant cause of rapidly rising temperatures since the 1950s.

The international panel of climate change experts also warned that: “The available evidence indicates that global warming greater than a certain threshold would lead to the near-complete loss of the Greenland Ice Sheet over a millennium or more, causing a global mean sea level rise of about 7m.”

Establishing the exact temperature threshold needed to melt away the Greenland Ice Sheet was difficult to predict, though some studies suggested the threshold could be as low as a 1ºC global temperature rise.

Even if global emissions were reduced dramatically, sea level and temperatures would continue to rise for several centuries thereafter. - The Mercury