Underappreciated majority of solid waste: Insufficient data and unclear impacts
The escalating generation and accumulation of solid waste is one of the greatest challenges that our society and global ecological systems are facing. Management of municipal solid waste (MSW) is a substantial contributor to greenhouse gas (GHG) emission,1 which has become a policy focal point at the recent Conferences of the Parties to the United Nations Framework Convention on Climate Change (COPs). However, the broad concept of solid waste extends far beyond MSW. MSW corresponds to the tertiary sector, which includes waste generated by households, retailers, and public service providers. The other elementary solid waste streams are industrial waste (IW) and agricultural waste (AW), which correspond to the secondary and primary sectors, respectively.
We highlight the two most critical problems related to IW and AW herein, emphasizing the necessity to expand the current research fervor of MSW to IW and AW. First, the generation of these waste streams is disproportionally poorly quantified considering the massive outputs of industrial and agricultural activities. Preliminary estimations by the World Bank suggest that the global annual generations of IW and AW can reach 18 and 5 times greater than that of MSW by mass, respectively, while accurate inventories are unavailable.2 Second, the environmental impacts of IW and AW remain inadequately quantified on a global scale, with disproportionately high emphases on high-income countries and little attention to the Global South.
Inadequate quantification of IW and AW
We firstly overview the available estimations of IW (Figure 1B) and AW (Figure 1C) generations globally. The data are even incomplete for the top ten industrial and agricultural production countries, respectively. The available data on IW and AW are primarily concentrated in North America, Western Europe, East Asia, and Southeast Asia, with a noticeable absence of reliable data from Latin America, Sub-Saharan Africa, and the Commonwealth of Independent States.
