Re-assessing global municipal solid waste generation

Abstract

This study contributes to estimate the total waste generated at global level. A few studies have provided an efficient and comprehensive global estimate. However, data reporting is globally inconsistent due to varying interpretation of terminology, lacking standardised categories and varying methodologies used to observe and measure waste amounts. This study employs regression analysis and material flow analysis approaches to ensure a cross-comparability of waste generation data. The result implies that total global waste arisings are around 20 billion tonnes in 2017. This corresponds to 2.63 tonnes of total waste per capita (cap) per year. The total global waste generated is expected to grow to 46 billion tonnes by 2050 under a business-as-usual scenario. Municipal solid waste (MSW) is a much smaller amount, ranging from 2.3 to 3.1 billion tonnes (average of 2.7 billion tonnes) in 2019. This figure reflects an increase of between 30% and 50% in MSW generated during the last 15 years (2004-2019). MSW generated is expected to grow to 2.89-4.54 billion tonnes by 2050, depending on which assumptions are used. This represents a 26%-45% increase compared to 2019. The overall assessment in this study reveals that almost one-third of the total MSW generated is not collected, and most of what is collected is not treated accordingly to current ideas of sound management. Moreover, almost 42% of MSW goes to open dumping or uncontrolled burning. The finding provides valuable insight for policymakers to design and assess circular economy policy instruments towards achieving sustainable development goals.

Keywords: Waste generation; circular economy; forecasting; global waste; material flow analysis-based accounting; municipal solid waste; regression analysis-based accounting; waste disposal; waste estimation.

Figure 1.

Total waste generation and composition at the global level. (a) Total waste generated worldwide. It shows the total global waste generated in billion tonnes year⁻¹ from 2004 to 2017 by main waste material groups (left-axis) and in tonnes cap⁻¹ year⁻¹ (right-axis). In principle, it is possible to attempt to extrapolate from the global material extraction (DE) data, to estimate the total worldwide waste arisings. Such extrapolation was facilitated by the availability of DE data from Krausmann et al. (2018) for the period 2004–2015 and from UNEP, International Resource Panel (2021) for the period 2016–2017. (b) Main waste material composition worldwide. Based on composition of end of life and processing waste in the material and product life cycle.

Figure 2.

Projected total waste generated worldwide. (a) Total waste generation worldwide from 2004 to 2050. (b) Projected total waste generation worldwide from 2017 to 2050. Global projected scenario of total waste generated in billion tonnes year⁻¹ (left-axis) and in tonnes cap⁻¹ year⁻¹ (right-axis). 2004–2017 historic data, and 2018–2050 scenario results. The global material extraction (DE) data from Krausmann et al. (2018) and UNEP (2021) were used to estimate the total global waste and to develop projections to 2030 and 2050.

Figure 3.

Range of MSW generation for the period 2004–2019. Scenario definitions: MFA (11%): material flow analysis scenario based on MSW generated is 11% of the total global waste arisings. MFA (15%): material flow analysis scenario based on MSW generated is 15% of the total global waste arisings. WASTE ATLAS: scenario based on the regression model (equation (1)). GWMO: scenario based on the regression model (equation (2)). WORLD BANK: scenario based on the regression model (equation (3)).

Figure 4.

Projected MSW generation (2019–2050). Scenario definitions: 2019: describing baseline scenario for current year. 2050 S1: describing projection scenario considering same waste generation per cap as in 2019. 2050 S2: describing projection scenario considering an increase in waste generation per capita by 15% with respect to 2019. Data sources: MSW generation: based on model predictions from current study. World population: based on (United Nations Department of Economic and Social Affairs Population Dynamics, UNDESA (2019)). GDP per capita, PPP (constant 2011 international dollars): World Bank (2021).

Figure 5.

Worldwide Waste Management practices for the year 2019. AD: anaerobic digestion.