However, we were interested in how much influence unforced variability might have had on changes in the rate of
warming over the instrumental period.
Not exact matches
=== > That the different
period cooling /
warming trends exist in narrow to wider bands
over the total
instrumental temperature record
Over the
instrumental period (since the 1850s), North Atlantic SSTs show a 65 to 75 year variation (0.4 °C range), with a
warm phase during 1930 to 1960 and cool phases during 1905 to 1925 and 1970 to 1990 (Schlesinger and Ramankutty, 1994), and this feature has been termed the AMO (Kerr, 2000), as shown in Figure 3.33.
This time
period is too short to signify a change in the
warming trend, as climate trends are measured
over periods of decades, not years.12, 29,30,31,32 Such decade - long slowdowns or even reversals in trend have occurred before in the global
instrumental record (for example, 1900 - 1910 and 1940 - 1950; see Figure 2.2), including three decade - long
periods since 1970, each followed by a sharp temperature rise.33 Nonetheless, satellite and ocean observations indicate that the Earth - atmosphere climate system has continued to gain heat energy.34
C&W
warmed about 8 - 9 % more
over the
instrumental period.
Several analyses of ring width and ring density chronologies, with otherwise well - established sensitivity to temperature, have shown that they do not emulate the general
warming trend evident in
instrumental temperature records
over recent decades, although they do track the
warming that occurred during the early part of the 20th century and they continue to maintain a good correlation with observed temperatures
over the full
instrumental period at the interannual time scale (Briffa et al., 2004; D'Arrigo, 2006).