Geoscience Reference
In-Depth Information
the existence of the opposite cooling trend (the problem of SST data reliability
needs serious attention).
According to the data of Levitus et al. (2000), during the last 50 years (1948
-
1998) the World Ocean has substantially warmed. The upper 300-m layer has
warmed most (by 0.31
°
C, on the average), whereas the temperature of the 3-km
layer increased by 0.06
C. This increase of the temperature of the upper layer of
the ocean had preceded the SAT increase started in 1970.
Satellite data on the sea ice cover extent are important as an indicator of the
global climate dynamics. Gloersen et al. (1999) detected a statistically substantial
decrease of the global area of sea ice, constituting (
°
0.003) 10
6
km
2
per
−
0.01
±
10 years.
Microwave remote sensing data is quite special, analysis of which has not
revealed any substantial changes of average temperature of the lower troposphere
during the last decades. This is con
rmed also by results of aerologic soundings.
From the data of Woodcock (1999a, b), the global mean SAT in October 1999 was
0.2
°
C below the average value for the period 1979
-
1999. The earth
'
s average
temperature rose by 0.8
C during the last century. That change is in the mean
global temperature that has been calculated for each year since 1880. The history of
average global temperature is based on data gathered around the world at weather
stations, on ships and by satellites. Despite the overall increase, global temperatures
have not climbed steadily during the decades. The average global annual temper-
ature hovered around 13.7
°
C from the 1880s through the 1910s. During the 1920s
-
1940s, temperatures climbed about 0.1
°
C each decade. The mean global temper-
atures were then stabilized at roughly 14.0
°
C until the 1980s. The world has mainly
grown hotter since 1980, at a rate of nearly 0.2
°
°
C per decade. The annual global
temperature from 2000 to 2009 was 0.61
°
C higher than the average temperature for
1951
1980. If the current rate of increase continues, the world will warm by 2
°
Cin
-
the next century. The years 2010
2013 were warmest in the GISS analysis:
-
The global land and ocean surface temperature (land and ocean) for 2010 tied
(with 2005) as the warmest of the 131-year record.
The year 2010 was also the wettest year on record, globally, in terms of pre-
cipitation measured. Precipitation in 2010 was much more variable than tem-
perature on smaller scales (region-to-region and even within regions). This is
typical of any year.
The year 2010 tied with 2005 in all three global-scale components: the global
land temperature, the global ocean temperature, and the global land and ocean
surface temperature.
The year 2010 was the 34th consecutive year with a global temperature above
the 20th century average. The last year with a global temperature below the
average was 1976.
December was the 310th consecutive month with a global temperature above the
20th century average. The last month with below average temperatures was
February 1985.
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