Read the following text and write a sentence describing the main idea. Scientists have found that 2014 was the hottest year ever on record. Since 1880, average temperatures have increased by 1.4 degrees Fahrenheit. Most of the temperature increases have occurred over the past 30 years. This is the result of greenhouse gasses. Experts do not expect the warming to slow down. Some think 2015 could be another year of record heat.