Read the following passage and mark the letter A, B, C. D on your answer sheet to indicate the best answer to each of the following questions from 23 to 30.
Solar radiation management (SRM or solar geoengineering) is a theoretical approach to reducing some of the impacts of climate change by reflecting a small amount of sunlight back out into space.
SRM would not directly reduce concentrations greenhouse gases, and therefore numerous expert reports have concluded that it could never be a complete solution to global warming and does not represent a substitute for mitigation of greenhouse gas emissions. However, they have also concluded that it might be able to reduce some climate risks. For instance, if it could be made to work, SRM would be the only known method for quickly stopping the rise in global temperatures. It could even be used to cool the planet, should that ever be necessary.
A variety of SRM techniques have been proposed, but those receiving the most attention from researchers involve brightening marine clouds by spraying seawater into the lower atmosphere, or replicating the cooling effect of volcanoes by spraying reflective sulphate particles into the upper atmosphere.
It is not yet known what all the side effects of SRM could be, or whether they would be very damaging.
Some possible side effects are known, however. For instance, the sprayed particles, or aerosols, might delay the regeneration of the ozone layer. There might also be some health effects from the additional aerosols in the atmosphere, although these are not currently expected to be large.
(Adapted from srmgi.org)
