es0c02273_si_001.pdf (773.07 kB)
Global Riverine Plastic Outflows
journal contribution
posted on 2020-08-06, 22:01 authored by Lei Mai, Xiang-Fei Sun, Lin-Lin Xia, Lian-Jun Bao, Liang-Ying Liu, Eddy Y. ZengGlobal
marine plastic pollution, which is derived mainly from the
input of vast amounts of land-based plastic waste, has drawn increasing
public attention. Riverine plastic outflows estimated using models
based on the concept of mismanaged plastic waste (MPW) are substantially
greater than reported field measurements. Herein, we formulate a robust
model using the Human Development Index (HDI) as the main predictor,
and the modeled riverine plastic outflows are calibrated and validated
by available field data. A strong correlation is achieved between
model estimates and field measurements, with a regression coefficient
of r2 = 0.9. The model estimates that
the global plastic outflows from 1518 main rivers were in the range
of 57,000–265,000 (median: 134,000) MT year–1 in 2018, which were approximately one-tenth of the estimates by
MPW-based models. With increased plastic production and human development,
the global riverine plastic outflow is projected to peak in 2028 in
a modeled trajectory of 2010–2050. The HDI is a better indicator
than MPW to estimate global riverine plastic outflows, and plastic
pollution can be effectively assessed and contained during human development
processes. The much lower global riverine plastic outflows should
substantially ease the public’s concern about marine plastic
pollution and financial pressure for remediation.