WASHINGTON, USA: Deflecting solar rays from the earth could be one way of improving food output, as global warming aggravates the likelihood of crop failures in the heat-stressed tropics.

One proposal for cooling the planet is to use high-flying airplanes to constantly replenish a layer of small particles in the stratosphere that would scatter sunlight back to space.

The idea has been inspired by big volcanoes placing lots of small particles in the stratosphere, which cool the earth, but the particles fall out within a year and the planet heats back up.

New research led by Carnegie Institute's Julia Pongratz concludes that similar geo-engineering would be more likely to improve rather than threaten food security, as feared in certain scientific establishments, the journal Nature Climate Change reports.

Pongratz's team, which included Carnegie's Ken Caldeira and Long Cao, as well as Stanford University's David Lobell, used models to assess the impact of sunshade geo-engineering on crop yields, according to a Carnegie statement.

"In many regions, future climate change is predicted to put crops under temperature stress, reducing yields. This stress is alleviated by geo-engineering," Pongratz said. "At the same time, the beneficial effects that a higher CO2 concentration has on plant productivity remain active."

The models also predict that some areas could be harmed by the geo-engineering. For example, deployment of such systems might lead to military conflict. Furthermore, these approaches do not solve the problem of ocean acidification, which is also caused by carbon dioxide emissions.