Want to know what the weather will be like in 2050? A worldwide effort is under way to provide an answer - and anyone with a computer can help, writes Dick Ahlstrom.
Will the world turn into a giant snowball by 2050, after falling prey to a runaway "ice age super greenhouse oscillation"? Or will things be pretty much the same as they are today, a bit warmer than last year but otherwise OK?
We could have a definitive answer in a year or two thanks to a novel international effort involving ordinary people. The world's largest climate- prediction experiment is under way, launched last Friday, on the closing day of the British Association's annual festival of science.
The goal of the exercise is to predict the impact of climate change and come up with an estimate of climate for 2050. The nice thing is that anyone can take part and help make the prediction.
People with access to a computer are being asked to log onto www.climate prediction.net and download a free copy of the same weather-prediction model used by meteorological agencies around the world, including Met Éireann and the UK Met Office.
Once installed the model will run in the background, doing weather predictions day after day, running through to 2050. All participants see is a small window in a corner of their screen, says Dr Myles Allen of the University of Oxford, who is involved in the project.
"The model is not a toy," says Allen. "We haven't changed the model at all." What they have done, however, is provide each copy of the model with a slightly different range of starting points for temperature, wind, air pressure and so forth. The model can juggle 10 million variables, he says, and each model can therefore deliver a slightly different version of what the climate will be in 2050.
Participants will be able to open up their models to monitor proceedings. A picture of Earth is displayed, so you can watch cloud masses form and storms pass while you view sunrises and sunsets over Ireland.
If the model ran without being put on hold, say when a computer is switched off, it would still take four weeks of iterations to complete a run to 2050, says Allen. At that time it will ask you to upload the final weather conditions, information to be added to the results from a hoped-for two million participants. "This is a way to access computer horsepower that is unavailable in a normal context," he says.
The modelling also mimics how ordinary forecasting is done, he adds. Met Éireann would run the model 20 or 30 times to build an "ensemble" of predictions that gives a good picture of what tomorrow's weather holds.
The initiative, by the universities of Oxford and Reading, the UK Met Office, the Open University, the Rutherford Appleton Laboratory and Tessella Support Services will harness the combined power of our personal computers to generate the world's most comprehensive probability-based forecast of 21st-century climate yet produced.
Already the models are throwing up surprises. One unexpectedly predicted a runaway greenhouse effect, which in turn sparked a dramatic ice age that left Earth snowbound in just 50 years. Allen believes this is possible but highly unlikely, although he admits he will need more data to rule this and other extreme results out of bounds.
The final weather ensemble will be handed over to the Intergovernmental Panel on Climate Change to help policy-makers the world over plan for climate change.
If you are interested in participating in the programme you can download the free software and climate model by going to www.climateprediction.net and following the instructions