WASHINGTON: Earth’s heat is stuck on high. Thanks to a combination of global warming and an El Nino, the planet shattered monthly heat records for an unprecedented 12th straight month, as April smashed the old record by half a degree, according to federal scientists.The National Oceanic and Atmospheric Administration’s (NOAA) monthly climate calculation said that earth’s average temperature in April was 14.8 degrees Celsius. That is 1. 1C warmer than the 20th century average and well past the old record set in 2010.The Southern Hemisphere led the way, with Africa, South America and Asia all having their warmest Aprils on record, NOAA climate scientist Ahira Sanchez-Lugo said. NASA was among other organisations that said April was the hottest on record. The last month that wasn’t record hot was April 2015. The last month Earth wasn’t hotter than the 20th-century average was December 1984, and the last time Earth set a monthly cold record was almost a hundred years ago, in December 1916, according to NOAA records.“These kinds of records may not be that interesting, but so many in a row that break the previous records by so much indicates that we’re entering uncharted climatic territory (for modern human society),” Texas A&M University climate scientist Andrew Dessler said in an e-mail. At NOAA’s climate monitoring headquarters in Asheville, North Carolina, we feel like broken records state the same thing each month, Sanchez-Lugo added. And more heat meant record low snow for the Northern Hemisphere in April, according to NOAA and the Rutgers Global Snow Lab. Snow coverage in April was 890,000 square miles below the 30-year average.Sanchez-Lugo and other scientists say ever-increasing man-made global warming is pushing temperatures higher, and the weather oscillation El Nino — a warming of parts of the Pacific Ocean that changes weather worldwide — makes it even hotter.The current El Nino, which is fading, is one of the strongest on records and is about as strong as the 1997-1998 El Nino. But 2016 so far is 0.45C warmer than 1998. “So you can definitely see that climate change has an impact,” added Sanchez-Lugo.Given that each month this year has been record hot, it is not surprising that the average of the first four months of 2016 were 1.14C higher than the 20th-century average and beat last year’s record by 0.3C. Last year was the hottest year by far, beating out 2014, which, too, was a record.But 2016’s start “is unprecedented basically” and in general half a degree warmer than 2015, Sanchez-Lugo said. Even though El Nino is fading and its cooler flip side La Nina is forecast to take hold later this year, Sanchez-Lugo predicted that 2016 will end up the hottest year on record for the third straight year.That’s because there is a lag time for those changes to show up in global temperatures and because 2016 has started off so much hotter than 2015, she concluded.