The last four years have been the hottest on record. Experts say it’s the continuation of an upward trend that’s been present for more than 50 years.
Experts said there are always temperature fluctuations year to year, and short term variations don’t mean much. But, they said, when you measure variations over a 50 year span it's easier to spot meaningful trends.
While it’s been gradually getting warmer, the last four years in particular have been the hottest on record.
Sarah Green is a professor in the chemistry department at Michigan Technological University. She said the science behind the earth's warming is well established.
“The cause is greenhouse gases that are accumulating in the atmosphere, and we know they’re accumulating because that’s a chemical measurement that’s quite routine to do and it’s being done everywhere and is has been done very consistently since the 50’s.”
Green said on average, our planet is more than two and a half degrees fahrenheit warmer than it was in the 1950’s.
For a link to a climate change simulator, click here. To see global temperature flucuations, click here.