Now that December is over and the temperature data for the whole
year has been collected, the Met Office have said, provisionally,
that 2011 was the
UK's second warmest year on record.
It reports:
"The mean temperature so
far this December has been 4.7 °C, 0.5 °C above the 1971-2000
average. This is a big swing from 2010, when temperatures were 5 °C
below average to notch up the coldest December on
record."
But as Met Office National Climate Manager John Prior points
out:
"While it may have felt mild for many so
far this December, temperatures overall have been close to what we
would expect.
"It may be that the stark change from last year, which was the
coldest December on record for the UK, has led many to think it has
been unseasonably warm."
The Met Office goes on to say that 2011 has been a
record-breaking year:
"It was the warmest April and Spring on
record, and the second warmest Autumn on record.
"The highest single-day temperature for October was also broken -
with Gravesend in Kent notching up 29.9 °C on 1 October, beating
the previous record of 29.4 °C at March in Cambridgeshire on 1
October 1985.
"The top temperature in 2011 was 33.1 °C on 27 June at Gravesend
in Kent - which was the warmest temperature recorded in the UK for
five years."
And it's not just temperature records that have been broken:
"... with Scotland having its wettest
year on record with 1859.5mm of rain (beating the previous record
set in 1990). On the other hand, some parts of England have had
very low levels of rainfall - East Anglia had its second driest
year on record with 449mm of rain and the Midlands its third driest
with 586.5mm."
What does this tell us about climate change?
The Met Office points out that there is a continuing temperature
difference from one year to the next:
"... The annual figures for 2011... show
the year is expected to be the second warmest on record for the
UK.
"Up to 28 December, 2011 currently has an average temperature of
9.62 °C. This is a big change from 2010, which was the 12th coldest
year on record with 7.97 °C."
This sort of dramatic temperature variation from one year to the
next highlights the need to consider longer time-periods when
trying to uncover a long-term temperature trend.
The following video succinctly explains the difference between
short-term variation and long-term trend.
From Climate
Denial Crock of the Week
So considering data from just one year cannot tell us much about
longer-term climate change.
In this case, as the Met Office point out, the 2011 average
temperature is in line with the UK's long-term temperature trend,
being above the 1971 - 2000 average:
"This year marks a return to a trend of
warmer than average annual temperatures - all the UK's top seven
warmest years happened in the last decade, with 2006 leading the
list with 9.73 °C."
The Met Office have also released its
annual global temperature forecast for 2012, which
states:
"2012 is expected to be around 0.48 °C
warmer than the long-term (1961-1990) global average of 14.0 °C,
with a predicted likely range of between 0.34 °C and 0.62 °C."