Staff at [the Irish Met Office] Met Éireann have been told to be noncommittal if asked whether specific extreme weather events in Ireland could be linked to global warning.
The advice is contained in a guidance document on what to do when hurricanes, droughts, heatwaves and snow storms are being blamed directly on climate change. In its “climate attribution statement” Met Éireann said questions linking these specific events to global warming were to be expected.
“There is no simple yes or no answer to the question,” the guide says. “It is a fact that a current weather event is occurring in a climate that is approximately one degree celsius warmer than pre-industrial times.
“But that alone does not mean that the event would not have occurred if the climate were colder by one degree.” The guide says extreme weather events are more likely to occur because of global warming but that linking it to specific events is a problem.
“A comment along the lines of ‘we can’t say if the event is a result of climate change, but it is the type of event that is projected to occur more frequently in a changed climate’ can be used if the question arises,” it says.
The guide was much clearer on what to say when asked about the link between human activity and climate change. It says the fifth assessment report of the Intergovernmental Panel on Climate Change had concluded that “human influence on the climate system is clear”.
“Societies around the world are faced with increasing climate change risks,” according to the guide. It also explains that new climate modelling technology has been developed which might give clearer answers as to whether events such as the “Beast from the East” snow storm or Ireland’s summer heatwave could be linked to climate change.
The guide says: “These model simulations are expensive to run computationally so it is not possible to get information on attribution in real time. Results of attribution studies have statements like ‘the event is 30 per cent more likely to have occurred in a warmer climate’.”
The documents were obtained by the transparency group Right to Know using EU environmental information regulations.
Séamus Walsh, head of the Climatology and Observations division of Met Éireann, said: “There is no simple yes or no answer and often when we’re explaining this, we’re losing. Our forecasters deal essentially with the weather, which is the day-to-day variation. Everybody thinks because we all work in Met Éireann, we are all experts on climate change. But they are quite different skills so we like forecasters to talk on weather and our climate experts to talk on climate.”
He said that while the science was “more or less settled” on climate change, linking specific events to it was nowhere near as simple. “The difficulty with these attribution studies is people want to know today and it’s really not possible to do that.”