  The Ward et al. (2016) Plos-One paper is an important, heavily-cited paper in
the decoupling literature. The authors present evidence of 1990-2015 growth in
material and energy consumption and GDP at a world level, and for selected
countries. They find only relative decoupling has occurred, leading to their
central claim that future absolute decoupling is implausible. However, the
authors have made two key errors in their collected data: GDP data is in
current prices which includes inflation, and their global material use data is
the total mass of fossil energy materials. Strictly, GDP data should be in
constant prices to allow for its comparison over time, and material inputs to
an economy should be the sum of mineral raw materials. Amending for these
errors, we find much smaller levels of energy-GDP relative decoupling, and no
materials-GDP decoupling at all at a global level. We check these new results
by adding data for 1900-1990 to provide a longer time series, and find
consistently low (and even no) levels of global relative decoupling of material
use. The central claim for materials over the implausibility of future absolute
decoupling therefore not only remains valid but is reinforced by the corrected
datasets.
