According to a new report published by the Global Alliance for Incinerator Alternatives (GAIA), 70% of global greenhouse emissions originate from the material economy, from extraction through to the disposal process.
The report found that “in national inventories, these emissions are tallied in the industrial, agricultural, transportation, and energy sectors, as well as the waste sector.
“Yet curbing waste generation and implementing better waste management strategies avoid emissions throughout the life-cycle of material goods from extraction to end of life.”
According to GAIA’s report, zero waste systems contribute to the reduction in emissions in three ways:
● Source reduction and separate collection and treatment of organic waste to avoid landfill methane emissions.
● Land application of compost or digestate enhances the carbon uptake of the soil.
● Source reduction and recycling of all municipal waste streams reduces “upstream” emissions from natural resource extraction, manufacturing, and transport.
The report also offered four key climate mitigation strategies on how sustainable waste management practices can assist in reducing carbon and other greenhouse gas emissions.
Composting is a climate game changer
The report suggests that the separate collection of different waste streams is vital to avoid cross-contamination. For example, recyclable waste should not be disposed of or stored together with organic waste, as the most readily implementable treatment option for organic waste is composting.
Organic waste separated, collected and composted at the source, such as within your home or business, can reduce methane emissions by as much as 62% while the mechanical recovery and biological treatment of residual waste and biologically active landfill cover are good complementary measures to source-separate organic waste collection. When practised together, these strategies can reduce methane emissions by an average of 95%.
Zero waste model can transform the waste sector into a net negative source of GHG emissions
According to the report, if the world improved on existing waste management policies and implemented more sustainable practices such as waste separation, recycling and composting, the sector could cut total emissions from waste by 84%, which is equivalent to around 1.4 billion tonnes.
Aggressive recycling programmes reduce emissions in mining, forestry, manufacturing and energy, with the report finding that increased recycling would reduce annual GHG emissions in the waste sector by 35% in Detroit, 30% in Sao Paulo, and 21% in Lviv by 2030.
Combined, these two approaches can produce deeper emissions reductions than waste sector emissions. This is true even for relatively modest programs; full implementation of zero waste would produce even greater emissions reductions.
Best way to reduce GHG emissions is with a reduction at the source
Source reduction is a critical strategy for addressing food waste, which currently comprises one-third of all food production and is responsible for 10% of global GHG emissions. Other strategies for source reduction include restrictions on the production and distribution of single-use items and packaging.
The report said that “source reduction is especially important for plastic, most of which is not recyclable and whose production is doubling every 20 years.”
Energy recovery not an effective mitigation strategy
Recovering methane gas emanating from landfills is an unreliable strategy due to the large quantities of fugitive methane emissions allowed to escape.
Waste to power by way of incineration is a major source of GHG emissions, with the report finding that for each tonne of plastic burned, 1.43 tonnes of CO2 is released into the atmosphere.
All in all, the amount of energy generated by these activities is grossly insufficient to offset the carbon footprint of the technologies.