The UK’s Met Office has just released its decadal forecast for global weather. Over the first five years of the 2020s, the global annual average temperature is expected to be between 1.15°C and 1.46°C “above pre-industrial conditions”. There is a 10% chance of one of the years exceeding the Paris Accord target of 1.5°C above P-I.
The Met Office appears to be in step with the IPCC, accepting an 1850 start to industrial conditions and a minimum global average at the end of this year of 1.06°C. This figure, I think, is derived from the IPCC projection of a rise of global average temperature from one degree above pre-industrial in 2017 to 1.5°C in 2040, a straight line rise of 0.0217 degrees per annum.
If the Met Office is right and 1.5 is reached by 2024, the one chance in 10 odds that subsequent years will be as warm or warmer will shorten. How long will it be before every year has an average temperature “above Paris”? Well before 2040, possibly.
At the end of Week 9 this Meteorological Year, my five Northern weather Stations are running at 3.59°C above Pre-industrial. (Least warm is Rome at 1.99 and warmest Koltsovo at 7.52.)
The five Southern stations are much cooler. Rio de Janeiro is now 0.09°C BELOW Pre-industrial. Sydney’s running average increased from 1.21 to 1.52°C in the last 7 days. It is the only southern station in the “orange zone” (above Paris). The five together average 0.57°C above Pre-industrial, giving a 10 station global average of 2.08°C above P-I. This is a rate of warming for the year-to-date that is 47 times the IPCC projection. (The math is simple. The expected IPCC temperature at the end of the year is 1.0652 above P-I. Take this away from 2.08 and divide the result by 0.0217.)
I am quite taken by the difference between the hemispheres this year. Last year the South warmed more than the North.
The North is getting a bit warmer and the South a little cooler. The 10-station Globe Warmer Days percentage is currently 52, amusingly the proportion of Brits that voted for Brexit in 2016.