If You’re Under 35, You’ve Never Experienced “Normal” Temperatures
March 20, 2012
The current spring heat wave in eastern North America and elsewhere is surely getting a lot of people’s attention, but younger people, under 35, may not fully appreciate the degree to which it’s surprising to their older siblings, fathers or mothers.
The year 2011 tied with 1997 as the 11th warmest year since records began in 1880. The annually-averaged temperature over global land and ocean surfaces was 0.51°C (0.92°F) above the 20th century average of 13.9°C (57.0°F). This marks the 35th consecutive year (since 1976) that the yearly global temperature was above the 20th century average. The warmest years on record were 2010 and 2005, which were 0.64°C (1.15°F) above average. Including 2011, all eleven years in the 21st century so far (2001–2011) rank among the 13 warmest in the 132-year period of record. Only one year during the 20th century, 1998, was warmer than 2011.
Between 1998 and 2010, temperatures rose by 0.11C, 0.04C more than previously estimated.
The new data set also shifts around the hottest years on record, so that the new temperature series, known as HadCRUT4, is more in line with other global records held by NASA and NOAA in the US. The American series had already added Arctic temperatures from extrapolated information.
Before it was thought the hottest years were 1998 followed by 2010, 2005, 2003 and 2002. The updated series puts 2010 as the hottest year on record followed by 2005, 1998, 2003 and 2006.
The main conclusions of the new temperature series remains the same – that overall warming since 1850 has been around 0.75C and the 10 warmest years on record all occurred in the last 14 years.
Professor Phil Jones, director of CRU, who was at the heart of the Climategate scandal, said the temperature series is slightly warmer because it includes the new data from the Arctic, where the world is warming faster.
Most of the new data came from weather stations controlled by Russian scientists.
“HadCRUT is underpinned by observations and we’ve previously been clear it may not be fully capturing changes in the Arctic because we have had so little data from the area,” he said.
“For the latest version we have included observations from more than 400 stations across the Arctic, Russia and Canada. This has led to better representation of what’s going on in the large geographical region,” said Prof Jones.
The differences between two of the world’s most widely quoted temperature data sets, the NASA GISSTemp set, and the UK HadCRUT, have been responsible for a lot of confusion about what global temperatures are doing, and lead to the continued resilience of canards like “It’s been cooling since 1998″. With the differences now addressed, the two sets are more in accord. Met Office video below -