The UK Met Office has revised its global temperature predictions as a result of a new version of its climate model and climate simulations using it. It now believes that global temperatures up to 2017 will most likely be 0.43 deg C above the 1971 -2000 average, with an error of +/- 0.15 deg C. In reality this is a forecast of no increase in global temperatures above current levels.
The new forecast produced by the UK Met Office for the next five years is a considerable change from forecasts given in the past few years. An excellent comparison between the new and older forecasts can be found here.
It is worth comparing the current forecast with that made just five years ago. In 2007 The Met Office Hadley Centre reported to the UK Government that it had pioneered a new system to predict the climate a decade ahead. It said that the system simulated both the human-driven climate change and the evolution of slow natural variations already locked into the system. “We are now using the system to predict changes out to 2014. By the end of this period, the global average temperature is expected to have risen by around 0.3 °C compared to 2004, and half of the years after 2009 are predicted to be hotter than the current record hot year, 1998.”
Given that we have data for three of the five years of that period and all show no departure from a constant temperature when analysed statistically, this is a prediction that will probably be totally wrong. In any case it is completely at odds with the new forecast. We were also told that the recent temperature standstill was unimportant and that the underlying rate of global temperature increase continued at a constant 0.2 deg C per decade. This, as we pointed out, is only true if one considered decadal averages. If one considers 5-year averages then one arrives at a very different conclusion.
The new prediction challenges that assertion that the underlying rate of change of global warming is unchanged. According to the IPCC and the Met Office the unchanging 0.2 deg C underlying rate of global warming should have resulted in a 0.4 deg C rise in global temperature between 1997 -2017. That this has not happened is because of a global cooling offset that has precisely kept pace with the greenhouse gas forcing that wants to raise the Earth’s temperature every year. We have pointed out that this equivalence of the warming and cooling factors, and their associated feedbacks, is not just an average but also a year on year balancing act. This behaviour is scientifically suspicious.
That the global temperature standstill (observed from 1997 to the present) could continue to at least 2017 would mean a 20-year period of no statistically significant change in global temperatures. Such a period of no increase coming at a time when greenhouse gas forcing is rising will pose fundamental problems for climate models.
If the latest Met Office prediction is correct, and it accords far more closely with the observed data than previous predictions, then it will prove to be a lesson in humility. It will show that the previous predictions that were given so confidently as advice to the UK government and so unquestioningly accepted by the media, were wrong, and that the so-called sceptics who were derided for questioning them were actually on the right track.