Integrated waste management as a climate change stabilization wedge

Abstract

Anthropogenic sources of greenhouse gas emissions are known to contribute to global increases in greenhouse gas concentrations and are widely believed to contribute to climate change. A reference carbon dioxide concentration of 383 ppm for 2007 is projected to increase to a nominal 500 ppm in less than 50 years according to business as usual models. This concentration change is equivalent to an increase of 7 billion tonnes of carbon per year (7 Gt C year—1). The concept of a stabilization wedge was introduced by Pacala and Socolow ( Science, 305, 968—972, 2004) to break the 7 Gt C year— 1 into more manageable 1 Gt C year— 1 reductions that would be achievable with current technology. A total of fifteen possible ‘wedges’ were identified; however, an integrated municipal solid waste (MSW) management system based on the European Union’s waste management hierarchy was not evaluated as a wedge. This analysis demonstrates that if the tonnage of MSW is allocated to recycling, waste to energy and landfilling in descending order in lieu of existing ‘business-as-usual’ practices with each option using modern technology and best practices, the system would reduce greenhouse gas emissions by more than 1 Gt C year —1. This integrated waste management system reduces CO2 by displacing fossil electrical generation and avoiding manufacturing energy consumption and methane emissions from landfills.