NASA: previous 12 months hottest ever
According to NASA the average temperature over the last 12 months reached a record high (click here). Provisional data published elsewhere suggests that nine countries have recorded their hottest ever temperatures, including 44°C in Russia earlier this month and 53.5°C in Pakistan in May.
The significance of this year’s temperature records is that hot weather is often associated with El Niño events when heat stored in the Pacific Ocean is transferred into the atmosphere. But the recent El Niño has not been particularly strong and the heat waves have coincided with a period when the heat from the sun (irradiance) has been at a minimum. So the explanation for why the planet is so hot at the moment is a strong underlying global warming trend due to rising green house gases together with a moderate El Niño.
Whether 2010 turns out to be the hottest year on record will depend on the speed and strength of La Niña which does the opposite of El Niño by soaking up atmospheric heat. But future El Niño events coinciding with periods of stronger solar activity look likely to break this year’s highs.
Posted: 23rd July 2010.
Tags: Climate Science.