An international team of scientists says global warming can be slowed in the short run – preventing millions of deaths from dirty air – by reducing methane and soot, according to the Associated Press. The researchers said soot causes rainfall patterns to shift, and reducing it would lessen droughts in southern Europe and parts of Africa and also ease monsoon problems in Asia.

After running computer models of 400 existing pollution-control measures, the scientists arrived at 14 methods that attack methane and soot. While the idea has been around for more than 10 years and the same authors worked on a UN report last year, the new study, published in Science, is far more comprehensive.

Meanwhile, another study, published in Nature Geoscience, showed that an atmospheric increase in aerosols – minuscule particles that include soot, dust and sulphates – has led to more rainfall in some regions and could provide vital clues for future climate predictions, Reuters said.

Climate change has become so politicised in the United States that “scepticism” of the broad scientific consensus linking it to fossil-fuel use has reached school classrooms, echoing past disputes over evolution, according to the Los Angeles Times. In a number of states, scientists and educators are seeing mounting resistance to the study of man-made climate change in middle and high schools.

Introducing tradeable quotas for catching whales could reduce the number of the marine mammals killed each year, the Press Association reported American researchers as suggesting. Writing in Nature, the academics said a market of quotas that could be bought and sold would allow environmental groups to “purchase whales” to save them and also let whalers profit from the animals without killing them.

A US safety regulator will examine whether pipelines carrying petroleum from Canada’s oil sands are at greater risk for spills than those carrying other types of crude, according to Reuters. Some environmental groups believe diluted bitumen from the oil sands is more corrosive than other grades of oil, but no definitive peer-reviewed research has been conducted.

Bulgarian legislators have begun debating a ban on hydraulic fracturing, or fracking, further threatening the oil giant Chevron’s plans to explore shale-gas deposits in the country, Bloomberg News reported. The government withdrew a previously granted exploration license from Chevron earlier this week after hundreds of Bulgarians protested in Sofia against the drilling technique, fearing it will pollute water and soil in the country’s most fertile farm region.

Geothermal energy developers plan to pump over 90 million litres of water into the side of a dormant volcano in the north-western US state of Oregon this summer, according to the Associated Press, in the hope that the water will return to the surface fast enough and hot enough to create cheap, clean electricity – without shaking the earth. The process, called hydroshearing, is similar to fracking but does not use chemical-laden fluid and is said to create only tiny rock fractures.