Global temperatures were above average for the 36th straight year in 2012, with parts of the Northern hemisphere experiencing their warmest year on record, US scientists said Tuesday. The year 2012 marked the 10th warmest since records began in 1880, with the global average temperature 0.57 degrees Celsius (1.03 Fahrenheit) higher than in the 20th century, the National Oceanic and Atmospheric Administration said. The agency said last week that the continental United States experienced its warmest year on record in 2012. However, several areas including parts of Alaska, western Canada, central Asia and the Antarctic were cooler. Still, average global temperatures have been higher than the 20th century average of 13.9 Celsius (57.0 Fahrenheit) every year since 1976 and only one year in the 20th century -- 1998 -- was warmer than 2012, the agency said. Most mainstream scientists believe that global temperatures and extreme weather events are rising due to industrial emissions of carbon and other greenhouse gases, which trap heat inside the atmosphere.