Rosegrant et al. (2012a) also estimate the IWSR under the
Bioeconomy (BIO) scenario, which allows for faster agricultural
productivity growth due to increased R&D expenditure, as well as
significant improvements in water use efficiency – particularly for
the non-agricultural uses. Under the BIO scenario, more sustainable
agricultural production and water use allow for a global IWSR
of 0.75 in 2030, with far smaller declines in the Asian regions. The
range of regional changes is also more narrow, from 5.3% to 4.7%.
Here we adopt the most likely case – the BAU scenario in order to
provide an assessment of the likely impacts in the absence of
additional investments in R&D aimed at crop productivity.