Global Municipal Solid Waste (MSW) generates approximately 1.3 billion tons per year and this is expected to
increase to approximately 2.2 billion tons per year by 2025 [1]. The United States generates the most waste per
capita among OECD countries [2], approximately 730 kilograms per capita in 2013. Moreover, the United Statesproduced the most greenhouse gas emissions among the OECD countries [2]. Approximately 18.1% of total U.S.
methane emissions were generated from the waste landfills sector in 2013, which was the third largest contributor of
methane emissions in the United States [3].
Solid waste can result in adverse effects to human health and the environment [4]. In particular, waste produces a
large amount of greenhouse gas emissions, which is the most critical issue to global climate change [5]. According
to the Intergovernmental Panel on Climate Change (IPCC), the global surface temperature will increase by 4.8ºC,
and sea levels will rise by 0.82 m by 2100 [6]. In addition, the annual global GDP will drop between 5% and 20% if
greenhouse gas emissions do not decrease immediately. Therefore, the reduction of greenhouse gases is a critical
issue to be resolved.
Several efforts have been made in the past to reduce the waste produced by the U.S. government. The U.S.
communities’ actions, such as technological advancements, environmental regulations, and emphasis on resource
conservation and recovery, have significantly reduced the environmental impacts of municipal solid waste,
including greenhouse gas emissions [7]. However, neither the solid waste generation nor the recycling rate is
decreasing. The U.S. recycling rate is only 26%, which is lower than other OECD countries [8].
The current situation of the U.S. waste sector is severe. Not only is the waste generation per capita significantly
high, but so are greenhouse gas emissions from the waste sector. Thus, the main objective of this research is to
mitigate the solid waste and greenhouse gases from waste sector. In order to achieve the main objective, first, the
causal relationship with solid waste across the United States must be investigated. If the main cause of the solid
waste is verified, the amount waste can effectively be decreased. Second, it must be confirmed whether solid waste
and recycling waste influences greenhouse gas emissions from the waste sector. By verifying the relationship
between the waste and greenhouse gases from the waste sector, an appropriate strategy can be developed for
decreasing the amount of greenhouse gases from the waste sector. Lastly, based on the research results, important
insights and suggestions can be provided to policymakers on potential ways for reducing the solid waste and
greenhouse gas emissions from the waste sector.