In the DePreSys
forecast, internal variability offsets the effects of
anthropogenic forcing in the first few years,
leadingtononetwarmingbefore2008(Fig.4).
In contrast, the NoAssim forecast warms during
this period. Regional assessment to February 2007
(fig. S8) indicates that this initial cooling in
DePreSys relative to NoAssim results from the
development of cooler anomalies in the tropical
Pacific and the persistence of neutral conditions in
the Southern Ocean. In both cases, the DePreSys
forecast is closer to the verifying changes observed
since the forecast start date. Both NoAssim and
DePreSys, however, predict further warming
during the coming decade, with the year 2014
predictedtobe0.30°±0.21°C[5to95%
confidence interval (CI)] warmer than the observed
value for 2004. Furthermore, at least half of the
years after 2009 are predicted to be warmer than
1998, the warmest year currently on record. …
So the first serious attempt to incorporate initial conditions – to predict natural variability (ENSO) in a decadal forecast model. Some misses, but also some significant hits:
1998 – .63C
2004 – .54C
2010 – .72C
2011 – .60C – no
2012 – .63C – tie
2013 – .65C – yes
2014 – .74C – yes
2015 – appears to be .87C – yes
2016 – predicted to exceed .87C – if true, a yes
