Scientists look beyond usual suspects such as El Niño to explain record temperatures 

Natural phenomena including a volcano and human activity such as reducing sulphur-producing fuels may have contributed to global warming

Natural phenomena, including El Niño, and human interventions such as burning fossil fuels are regarded as the chief causes of global warming. But scientists are also looking at other less frequently anticipated causes. Stock picture: David Jones/PA

Scientists are wondering if global warming and El Niño have an accomplice in fuelling this summer’s record-shattering heat.

The European climate agency Copernicus reported that July was 0.3C hotter than the old record. That’s a bump in heat that is so recent and so big, especially in the oceans and even more so in the North Atlantic, that scientists are split on whether something else could be at work.