Going for the record: Can anything stop 2012 from being warmest ever?

With a little more than a month to go, 2012 is likely to come in as the warmest year on record for the lower 48 States. Of the past 14 years, 4 have had annual average temperatures that have either set or approached record values.  Such warmth over a short time period has not been observed since the 1930s. The cause of the warmth can be attributed to natural climate variability, such as El Nino events, combined with a long-term global warming trend caused by increasing greenhouse emissions.