Climateprediction.net news

18 APRIL 2006

If you are checking the date of your model regularly, you may notice 
it return to the year 1920. Many of you have also noticed that your 
models have been warming up faster than the real world did over the 
20th century.

We'd like to apologise for having to restart all the models.

Your efforts so far have not been wasted, but it does mean that the 
experiment will take longer. We would like to encourage you to keep 
running the experiment, because your contribution is still just as useful.

The reason for the reset is that the scientists at Oxford have 
discovered that one of the input files to the model hasn't been 
increasing the amount of sulphate pollution in the atmosphere 
(sometimes called the "global dimming" effect) as it should have done. 
So what you are seeing is the full impact of greenhouse warming not 
masked as it was in the real world by sulphate pollution.

The experiment you have done is still a useful contribution to 
scientific research, as well as a graphic illustration of how much 
warmer the world might already be were it not for the global dimming 
effect. But to make the most accurate prediction for the 21st century, 
we obviously want to use the best possible inputs over the 20th 
century. So, after much discussion, the scientists have decided the 
best strategy is to re-run people's climate models with corrected 
sulphate data, rather than trying to "fix" the problem after the 
event. This will mean that models will return to the year 1920, and 
begin running again.

There is nothing that you need to do as a result of this. Your 
computer will automatically pull in all the data it needs. We'd also 
like to stress that the model itself and the software it is running on 
are working perfectly: the only correction is to an input data file 
that the project was supplied with. So this development does not add 
any risk to your computer.

However, it does mean that the experiment will take longer to run than 
we originally estimated. Please do carry on running your model if you 
possibly can - it's still just as important that we try and get the 
best possible prediction of what our climate will be like in the future.

As you would expect, that also means that we will be reporting the 
results later than the May date we originally planned.

You can find out more technical information about this issue here:
www.climateprediction.net/board/viewtopic.php?t=4759

We should also point out that the data that we have collected so far 
is still useful. It will add to our understanding of the role that 
sulphate pollutants have in global warming.

http://www.bbc.co.uk/sn/hottopics/climatechange/updates1.shtml

http://climateprediction.net/newsb.php?id=0

geothermal