Scientists have agreed that, unusual as some weather event may be, a single event cannot by itself be clearly linked to the climate change they are predicting is going to occur as a result of the greenhouse gases we humans are sending into space.
What they have said is that climate change will result in more extreme weather events like unusual floods, and bitter cold and banks of snow that has swept across the American and European continents this winter.
So do we need to wait until we have an indisputable pattern stretching over ten or twenty years before we can assess whether climate change is occurring?
Although it is not possible to say events like unusual summer heat waves or this winter’s disastrous floods are definitively caused by climate change, it is possible, with sufficient computer power, to estimate the probability that this weather has or has not been caused by climate change. A probability of 5% might lead most of us to conclude that this was just a freak winter. A probability of 50% would be much more convincing that climate change was a major factor. It would be similar to saying, for instance, that if one tossed a coin 100 times, and if it came up heads 85% of the time, the probability is that the coin is not evenly balanced. It could be due tochance,but one would not want to bet one’s house on it.
Oxford University has announced a “citizen-science project” in which they hope to utilize enough computer power from volunteers to estimate just how likely it is that the unprecedented floods in Ireland and Britain in the last three months were caused by mere chance versus caused specifically by climate change. They hope to be able to announce this probability within a month.
If you are interested in understanding how computer simulations can help us understand what is happening, the Guardian newspaper has a good explanation that most non-specialists can understand.
And if you are interested in participating in the research, send an email to weather@home project. The Oxford team will be delighted to hear from you.