Cutting emissions from the global waste stream including the potent greenhouse gas methane, could play a part in combating climate change, a new Report released by the United Nations Environment Programme’s International Environmental Technology Centre, has revealed.
Titled: “Waste and Climate Change: Global Trends and Strategy Framework,” the Report examined the contribution the waste sector could make in the fight against climate change and suggested a strategy for increasing that contribution.
The Report also talked about how the waste sector could generate electricity and fuel by harvesting the methane from rubbish, making it (rubbish) a blessing than curse.
Globally, the waste management sector is contributing 3-5 per cent of man-made GHG emissions, equal from around the current emissions of international aviation and shipping, according to some estimates.
The Report said the waste sector was in a strong position of being able to move from being a source of emissions to being a major saver of them in part by harvesting the methane from rubbish tips for fuel and electricity generation.
Mr Nick Nuttall, UNEP Spokesperson and Head of Media, who launched the Report at the on-going COP 16 in Cancun said, the sector could play a major role in bridging the gap between where emissions needed to be in 2020 and where emissions were heading under the various pledges associated with the 2009 Copenhagen Accord.
“Every avenue, every opportunity and every option for cutting greenhouse gases needs to be brought into play if the world is to combat dangerous climate change and set the stage for a transition to a low carbon, resource efficient Green Economy urgently needed in the 21st century,” he said.
Mr Nuttall said, “The waste sector is already acting to minimize the impacts of potentially potent greenhouse gases like methane, but this is often done on a country by country basis. The time is ripe to scale up and deliver a far more coordinated and global response, especially in respect to developing economies.
“This offers multiple benefits ranging from curbing greenhouse gas emissions to generating new green jobs and increased access to energy from waste-into electricity projects,” Mr Nuttall added.
According to the Report, levels of uncertainty could be as high as 10-30 per cent for developed countries (with good data sets) to 60 plus per cent for developing countries that did not have annual data.
It said producing energy from waste to replace energy from fossil fuels, storing carbon in landfills and through the application of compost to soils and reducing the amount of primary materials used in manufacturing through waste avoidance and material recovery through recycling (avoiding the GHG emissions from the energy used to extract or produce the primary materials), could be harnessed.
Mr Nuttall further explained that methane emissions from landfills were generally considered to represent the biggest impact on the climate from the waste sector followed by incineration of waste.
“Methane is generated in landfills when microbes form and begin to break down organic matter, such as food, paper, wood or garden trimmings.
A roughly even mix of carbon dioxide and methane gas forms during the decomposition process, but the practice in some locations of burying or covering waste tips the mix in landfill gas in favour of methane,” he said.
Mr Nuttall said, “When that methane escapes into the atmosphere it is thought to have a global warming potential 25 times that of carbon dioxide over 100 years.
“Landfills that have gas recovery systems in place capture the methane and convert it into fuel and compost. Capture rates vary from landfill to landfill (because they depend on the mix of the materials dumped in them), but estimates from managed landfills in developed countries put capture rates at 50-80 per cent.
Citing an instance from the report, Mr Nuttall suggested that simply by diverting food, garden and paper waste to composting or recycling stations thereby reducing the amount of organic matter in landfills, emissions, could be cut by 250kg CO2-equivalent per tonne of municipal solid waste.
The report estimated that in many developing countries, the level of waste, which was organic and thus a potential source of methane emissions, was around 50 per cent and could, in a rapidly developing country such as China, represented more than half of the waste stream up to and beyond 2030 if no action was taken.
In Ghana, Accra alone produces about 2,000 tonnes of waste daily. Ghana could however take advantage and fast-track moves to turning waste into energy to help combat climate change.
Although average annual per capita waste generation in developing countries has been estimated at 10-20 per cent of that of developed countries, studies had shown that the figure was rising in response to economic and population growth.