Top 10 Weather & Climate Events of 2012

Next Tuesday NOAA is expected to announce that 2012 marked the warmest year in the contiguous U.S. since record keeping began more than a century ago.

But record heat was just one hallmark of the year we wrapped up earlier this week. From unprecedented heat waves, to Hurricane Sandy, to never-before-seen levels of Arctic melt, 2012 was an extreme year for climate-related events.

Many of these events served to highlight the growing role that global warming is playing in tipping the odds in favor of high-impact weather events.

Here is our list of the top 10 extreme weather and climate events of 2012. Our ranking system takes into account each event's severity, societal impact, unusualness (was it a relatively routine occurrence or something that stands alone in recorded history), and the potential ramifications the event suggests for the climate system as a whole.