Global dating info
The joint analysis of the University of East Anglia and the Hadley Centre ( also yields high global temperature for 2005, but a few hundredths of a degree cooler than in 1998.Record, or near record, warmth in 2005 is notable, because global temperature did not receive a boost from an El Niño in 2005.1 ), such as 19, decreases from 0.1°C at the beginning of the 20th century to 0.05°C in recent decades (4).Error sources include incomplete station coverage, quantified by sampling a model-generated data set with realistic variability at actual station locations (7), and partly subjective estimates of data quality problems (8).The temperature in 1998, on the contrary, was lifted 0.2°C above the trend line by a “super El Niño” (see below), the strongest El Niño of the past century.Global warming is now 0.6°C in the past three decades and 0.8°C in the past century.
Estimated 2σ error (95% confidence) in comparing nearby years of global temperature (Fig.
Scenario A was described as “on the high side of reality,” because it assumed rapid exponential growth of GHGs and it included no large volcanic eruptions during the next half century.
Scenario C was described as “a more drastic curtailment of emissions than has generally been imagined,” specifically GHGs were assumed to stop increasing after 2000.
It is no longer correct to say “most global warming occurred before 1940.” A better summary is: slow global warming, with large fluctuations, over the century up to 1975, followed by rapid warming at a rate ≈0.2°C per decade.
Global warming was ≈0.7°C between the late 19th century (the earliest time at which global mean temperature can be accurately defined) and 2000, and continued warming in the first half decade of the 21st century is consistent with the recent rate of 0.2°C per decade. Largest warming is in remote regions including high latitudes.