Do-it-yourself climate forecasting

For reasons that I won’t bore you with, a tiny but persistent proportion of my waking hours is engaged in the search for an accurate weather forecast for the south of England.

Infuriated by the efforts of BBC Radio Solent to liven up its daily forecast at the expense of coherence, I’ve resorted to the Met Office website.

Here I find an arbitrary east/west dividing line drawn straight through Winchester. This leaves me to choose between Penzance and Dover for my forecast. I can do better by looking out of the window.

The Met Office appears to agree. On Friday, it announced the creative decision to abolish its much derided long term seasonal forecast. Better to remain silent and appear foolish than to publish and be damned.

Last week too a rather similar approach was taken by a group of scientists connected with the Intergovernmental Panel on Climate Change, another forecasting institution under the cosh. Billed as the beginning of the fightback against rampant climate change scepticism, their report is a synthesis of 100 recently published scientific papers on the subject.

It’s curious that the conclusions deal solely with the interpretation of historic data for potential indicators of climate change such as sea temperature and Arctic ice. The scientists simply reaffirm that the trends can be explained only by the effect of human-generated greenhouse gas emissions. Not a squeak about the future.

I haven’t been able to read the report itself or ascertain its context but there’s a hint of a new tactic. People are more likely to be influenced by the weather they observe than by scientists bickering over mathematical predictions of the future.

For example, if you live in London and discover that the Thames Barrier had to be raised three times last weekend, you surely pause for thought. Journalist and author, Max Hastings, reports from Kenya in this weekend’s paper: “anybody who notices what has happened to Africa’s weather lately knows climate-change sceptics are ostriches.” Observation has power that forecasting can never match.

I found further evidence of scientific reticence this week in producing our climate change briefing for Morocco. The government there is in big trouble with climate change and has commissioned the World Bank in major research on the future of the country’s agriculture through the 21st century.

Only one “interim” section of the report has been published so far but its analysis of future crop yields, led by the Food and Agriculture Organization, is revealing. The brief leaves the scientists with no option but to publish forecasts and all the usual long term graphs of temperature, rainfall and yields are dutifully reproduced.

However, reading between the lines of the text, it’s clear that the scientists don’t want to know about anything beyond 2030. Such are the uncertainties that they describe their own longer term projections as “plausible” which is a euphemism for “please don’t quote us.”

As for the period up to 2030, numbers tend to vanish from the text in deference to a broad descriptive forecast of “gradually increasing aridity because of reduced rainfall and higher temperatures.” The approach has the virtue of common sense without letting the government off the hook of its formidable adaptation challenge.

An eye-catching feature of the Morocco report is its climate model claim to a grid resolution of 10 X 10 kilometres. The IPCC 2007 assessment used 250 X 250. My immediate reaction is that this is a drafting error for 100 X 100 but maybe my sense of disbelief was aroused by the name credited for the forecasting – the Hadley Centre is part of the Met Office.


this article was first published by OneWorld UK