Scientists Look Beyond Climate Change and El Niño for Other Factors That Heat Up Earth

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

The European climate agency Copernicus reported that July was one-third of a degree Celsius (six-tenths of a degree Fahrenheit) 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.

Scientists agree that by far the biggest cause of the recent extreme warming is climate change from the burning of coal, oil and natural gas that has triggered a long upward trend in temperatures. A natural El Niño, a temporary warming of parts of the Pacific that changes weather worldwide, adds a smaller boost. But some researchers say another factor must be present.