Impacts of Large-Scale Sahara Photovoltaic Solar Farms on Global Climate
and Vegetation Cover
Abstract
Solar energy, if carefully planned, can contribute to the attainment of
global climate mitigation goals by reducing reliance on fossil fuel
energy. It has been suggested that large-scale photovoltaic solar farms
envisioned over the Sahara desert would reduce surface albedo, leading
to increased rainfall and vegetation cover that would benefit the
regional environment while meeting the world’s energy demand. However,
adverse remote effects resulting from atmospheric teleconnections could
offset such regional benefits. We use state-of-the-art Earth-system
model simulations to evaluate the global impacts of Sahara solar farms.
Our results indicate a redistribution of precipitation causing Amazon
droughts and forest degradation, and global surface temperature rise and
sea-ice loss, particularly over the Arctic due to increased polarward
heat transport, and northward expansion of deciduous forests in the
Northern Hemisphere. We also identify reduced El Niño-Southern
Oscillation and Atlantic Nino variability and enhanced tropical cyclone
activity. All these remote effects are in line with the global impacts
of the Sahara land-cover transition ~6,000 years ago
when Sahara desert was wetter and greener. The improved understanding of
the forcing mechanisms of massive Sahara solar farms can be helpful for
the future site selection of large-scale desert solar energy facilities.