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Posted at 12:11 PM ET, 06/14/2012

La Nina exits, global temperature spikes: May second warmest on record


Temperatures compared to normal across the globe during May. (NOAA)
La Nina - the pattern associated with cool waters in the tropical Pacific that lowers the global temperature - has died. The Earth’s temperature is now strongly rebounding in response. Today, NOAA reports May was second warmest on record globally.

The May temperature was 1.19°F above the 20th century average. It marked the 36th consecutive May and 327th consecutive month with above average global temperatures.

The land temperature was warmest on record for the month, 2.18°F above average. The ocean temperature was 0.81°F above average and 10th warmest on record for May. In the Northern Hemisphere, the average temperature was warmest on record.

Steve Scolnik of the blog CapitalClimate published a blog headlined “All 13 Mays this Century in Warmest 14” (with a compelling chart).

Indicators of snow and ice, for the most part, were consistent with the global warmth in May:

Northern Hemisphere snow cover extent was second smallest in the 46-year record. Regionally, Eurasia had its all-time smallest snow cover extent and North America its eighth smallest.

Arctic sea ice was 3.5 percent below average or 12th smallest on record since 1979.

Antarctic sea ice, on the other hand, was 2.4 percent above normal, 15th largest in the 34-year record. (For quite a while, trends in Antarctic sea ice have run counter to other global snow and ice indicators, likely linked to complex changes in ocean circulation in the region. Temperatures in that same region have actually warmed (see academic paper)).


2012’s global temperature relative to average compared to the 5 warmest years on record (NOAA)
Taking a slightly longer view of global temperatures, as La Nina has waned over the course of this calendar year, the global temperature compared to average has trended upwards (see graph above). The January-May global average temperature (January-May) ranked 11th-warmest on record. But thanks to a warm April (ranking 5th warmest) and May (ranking 2nd warmest), the spring period (March-May) rank climbed to 7th warmest on record, 1.06°F above average.

Now that the La Nina event has concluded, tropical Pacific is in a “neutral” pattern (neither La Nina nor El Nino) and ocean temperatures have moderated. NOAA’s Climate Prediction Center says there is a 50 percent chance El Nino conditions will commence by the end of the year. The birth of El Nino would signify warming of the tropical Pacific and we might expect near record or perhaps record-breaking global temperatures given background elevated greenhouse gas levels.

Related: U.S. completes warmest 12-month period again, smashes spring record

By  |  12:11 PM ET, 06/14/2012

 
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