Extract from The Guardian
Climate scientists are regularly infuriated by the things politicians
say. But it’s not often they publish a scientific paper tearing a
politician’s comments to shreds.
Sophie Lewis, from the Australian Research Council’s centre for excellence in climate science, has done exactly that, dissecting statements about climate records made by the former prime minister Tony Abbott in 2013.
Last week, temperature figures showed 2015 was officially the hottest year on record. Before that, 2014 was the hottest year on record. And scientists are expecting 2016 to once again win the dubious honour.
Heat records are being broken with wild abandon. Last year, 10 months broke temperature records.
Climate scientists say a rise in the average temperature caused by greenhouse gas emissions makes extreme heat records more likely.
In 2013, the UN’s top climate official, Christiana Figueres, linked bushfires in Australia to climate change. Abbott called such claims “complete hogwash” and said drawing links between broken records and climate change was a sign of desperation.
He went on: “The thing is that at some point in the future, every record will be broken, but that doesn’t prove anything about climate change. It just proves that the longer the period of time, the more possibility of extreme events.”
Superficially it seems to make sense: if you wait long enough, you’re bound to see records fall. Lewis suspected many people shared Abbott’s interpretation, and set out to show it was wrong.
Lewis says she was frustrated by the gap she saw between what the science showed and what some politicians said was happening.
In a peer-reviewed paper published in the journal Weather and Climate Extremes, Lewis pulls Abbot’s comments apart, shred by shred.
The first way to understand Abbott’s claim is that in any system, the longer you wait, the more often you will see records fall. But Lewis points out that the exact opposite is true. In a system without any sort of trend, such as a random string of temperatures, the first one will be a record-breaker, by default. The second one will have a 50% chance of being a record-breaker. The third has a one in three chance of being a record breaker … and so on. In a very long temperature series, you should see very few records being broken, and they will break less often over time.
Unless, of course, there is a warming or cooling trend.
Alternatively, Abbott might simply have meant there was no connection between extreme heat records and climate change. Instead, natural variability might be to blame: natural variability includes things such as the El Niño phenomenon, which push temperature around year-to-year.
To test if that might be the case, Lewis ran a series of climate models in which the greenhouse effect was removed – so all that was left was natural variability. Unsurprisingly, in those models, high temperature records were less common than they are in reality. In other words, the record-breaking that we have seen cannot be explained by natural variation.
“It drives me mental that these sorts of statements go unaddressed,” Lewis says. She says scientific literature generally tries to simply explain what is happening, ignoring misunderstandings in the public sphere.
“This was an attempt to bridge that gap.”
Sophie Lewis, from the Australian Research Council’s centre for excellence in climate science, has done exactly that, dissecting statements about climate records made by the former prime minister Tony Abbott in 2013.
Last week, temperature figures showed 2015 was officially the hottest year on record. Before that, 2014 was the hottest year on record. And scientists are expecting 2016 to once again win the dubious honour.
Heat records are being broken with wild abandon. Last year, 10 months broke temperature records.
Climate scientists say a rise in the average temperature caused by greenhouse gas emissions makes extreme heat records more likely.
In 2013, the UN’s top climate official, Christiana Figueres, linked bushfires in Australia to climate change. Abbott called such claims “complete hogwash” and said drawing links between broken records and climate change was a sign of desperation.
He went on: “The thing is that at some point in the future, every record will be broken, but that doesn’t prove anything about climate change. It just proves that the longer the period of time, the more possibility of extreme events.”
Superficially it seems to make sense: if you wait long enough, you’re bound to see records fall. Lewis suspected many people shared Abbott’s interpretation, and set out to show it was wrong.
Lewis says she was frustrated by the gap she saw between what the science showed and what some politicians said was happening.
In a peer-reviewed paper published in the journal Weather and Climate Extremes, Lewis pulls Abbot’s comments apart, shred by shred.
The first way to understand Abbott’s claim is that in any system, the longer you wait, the more often you will see records fall. But Lewis points out that the exact opposite is true. In a system without any sort of trend, such as a random string of temperatures, the first one will be a record-breaker, by default. The second one will have a 50% chance of being a record-breaker. The third has a one in three chance of being a record breaker … and so on. In a very long temperature series, you should see very few records being broken, and they will break less often over time.
Unless, of course, there is a warming or cooling trend.
Alternatively, Abbott might simply have meant there was no connection between extreme heat records and climate change. Instead, natural variability might be to blame: natural variability includes things such as the El Niño phenomenon, which push temperature around year-to-year.
To test if that might be the case, Lewis ran a series of climate models in which the greenhouse effect was removed – so all that was left was natural variability. Unsurprisingly, in those models, high temperature records were less common than they are in reality. In other words, the record-breaking that we have seen cannot be explained by natural variation.
“It drives me mental that these sorts of statements go unaddressed,” Lewis says. She says scientific literature generally tries to simply explain what is happening, ignoring misunderstandings in the public sphere.
“This was an attempt to bridge that gap.”
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