Mumbai Warming

The Weather Station at Chhatrapati Shivaji International, Mumbai, returns the highest mean daily temperatures of my Northern Hemisphere Five. It is, however, bottom of the Ten Station Table for Year-to-Date Mean Temperature above my Pre-Industrial Baseline.

37_NorthYTDetc

From Week 8 through to 27 Mumbai was running a temperature below Pre-Industrial so its current state represents significant warming. Here are the Year-to-Date temperatures (°C) at the end of each month.

Mumbai_DecToJul

Some observers are already certain that 2019 is going to be the Earth’s hottest year on record. India has experienced periods of extreme heat this year, and water shortages are a great concern in parts of the sub-continent, but Mumbai is clearly not going to be contributing much to a global temperature record if it happens. However, seven of the last ten weeks have registered average Mean Temperatures above the Paris Accord ”target” of 1.5°C.

wks28to37_Mumbai

Here’s the Week 37 Table. Rome was toasty but, as indicated above, a bit chilly in the north-east of England.

37_FullTable

Northern Winter

It was 56 years ago, or thereabouts when a “new” maths teacher sat with me for some one-to-one tuition. After a few minutes, he told me what I already knew – I had no facility with figures. Mr Gibbins inspired me, though; I knuckled down. I’m sure he would have been amused had he known I got a job in a government department of statistics.

Anyway, the provisional temperature figures from my Ten Weather Stations are in. I don’t think, dear reader, that you will appreciate it if I throw too many at you, all at once. They tell a load of stories but  I’ll try to follow a moderation in all things strategy.

My original intention was to see if I could get an early warning of the onset of the promised Grand Solar Minimum – or of the sudden increase in temperature because of a threatened release of Arctic methane (from melting permafrost). The first three months of the current meteorological year don’t seem to point in either direction, definitively.

Yesterday, my YouTube recommendations included this video from Veritasium. It is quite short and, I thought, an excellent introduction to the uncertainties of Climate Change/Global Warming. I hope you will watch it.

Very briefly, I have copied the daily AVERAGE temperatures for Ten Weather Stations for the ten meteorological years from December 2008 to November 2018. For simplicity, I give each year the “name” of the 11-month year, viz 2009 to 2018, rather than 2008/9 to 2017/18 Averaging ten years of AVERAGE temperatures gave a ten-year baseline which enabled me to determine where warming has brought us since the start of the Industrial Age.

The Intergovernmental Panel on Climate Change and other organizations tell us that temperatures have risen n degrees since “Pre-Industrial” (or some more recent baseline of their devising). I have decided it is pointless agonising over which baseline and which temperature rise to choose.

I’ve settled for a rise of 0.85°C since 1710. I mentioned in an earlier post that I thought this was “conservative” and heard someone offer a one degree C rise since 1850 a few days ago. Really, any reasonable “ballpark” figure will do, as long is it is rigorously applied to all the weather stations in the project.

I have calculated the pre-industrial baseline figure for each day of the year for the ten stations and for this first quarter of the meteorological year deducted the actual daily AVERAGE temperatures reported to Weather Underground.

Given the nature of the 2009 to 2018 baseline, one would expect temperatures for any day in 2019 to have a 50% chance (roughly) of being warmer. And, given the variability of our weather, the difference could be many degrees warmer (or colder). Averaging the AVERAGE daily temperatures for a whole month and comparing the result with the average for the 10-year baseline will reduce the difference – but it still might be more extreme than you’d expect. Averaging the three months of the Northern Winter and Southern Summer will reduce the monthly differences further.

And, thinking ahead, averaging the AVERAGE daily temperatures for the whole meteorological year will yield an annual figure that can be set against a statement such as, “The average global temperature has increased by 0.85°C since the beginning of the Industrial Revolution”.

So, how have my 5 northern stations fared this winter compared to the 0.85°C above Pre-Industrial of 2009 to 2018?

NorthWinterAboveP-I

A note on the colour coding in the first column.

BLUE: below the Pre-Industrial Baseline!

GREEN: between 0 to 1.49°C above Pre-Industrial.

ORANGE: above the Paris Accord but below 2°C.

RED: 2°C and more above Pre-Industrial.

The amount of warming and cooling this quarter is indicated in the second column.

Novosibirsk is the coldest of the five locations but, given the brutality of the Polar Vortex in North America, the Washington DC result is more surprising. As I said, these figures are provisional. I’ll check!