While many of our politicians continue to deny man-made climate change is a reality, new figures reveal that human-caused climate warming may be the single biggest driving force behind recent glacial melt.
There’s a reason why we have the phrase “a glacial pace.” Everything about glaciers is slow, so even though we know they are melting due to the warming climate, it’s hard to get a fix on just how rapid that melting process is, when it began in earnest and, crucially, whether man-made climate change can be shown to have exacerbated the melting, and to what extent.
Now researchers from Canadian and Austrian university and publishing this month in the journal Science Express have been able to conduct a systematic analysis of data on glacial melt that is collected as part of the Randolph Glacier Inventory (RGI) initiative. The researchers say that glaciers actually provide a very neat way of looking at climate change because their responses are so slow to manifest. As a result, the researchers could, and with some accuracy, estimate the state of the glaciers as far back as 1851, and then begin to calculate the speed of glacial melt from there, adjusting for known reasons why melting may have slowed or sped up other than natural causes or what we’d call man-made climate change.
The figures showed that man-made climate change could be tracked over several decades, exacerbating standard melting patterns. What’s more, over the past couple of decades there has been a sharp upturn in glacial melt that the researchers believe is consistent with our modern manufacturing boom. In fact, they believe they can say that man-made global warming, and mainly the burning of fossil fuels such as oil and coal for energy, may be responsible for as much 69 percent of the glacial melt between 1991 to 2010.
To put that in more solid terms, the researchers were able to create a rough estimate for just how much ice is melting every year. They think that around 295 billion tons of ice melts every year due to human-linked climate change compared to just 130 billion tons related to natural causes.
Still, due to the way in which these figures were calculated based on estimates, there is a sizable margin for error on this and we do have to take that into account. Taking just the 1991 to 2010 figure as an example, the human contribution to glacier melt may be as low as 45 percent, or it could even be as high as 93 percent, but the researchers believe that the evidence suggests the 69 percent figure is probably closer to the real value. What isn’t in dispute here is the contribution of man-made climate change which, even at the lower end of the spectrum, remains considerable and worrying.
The research did turn up some surprises, however. When the researchers dug down into area-specific glacier melt, they found that man-made climate change may not have an effect on every area. For instance, they could see clear signs of human-contribution to melting in areas like Alaska, western Canada and Greenland, among many others. Yet some areas like the Andes gave figures that meant the researchers couldn’t link glacial melt to human influence with high confidence.
The researchers stress that they need to make improvements to their various climate models and to their data analysis methods to improve their confidence in all these figures, but the research has been welcomed by other climate scientists who are quoted as saying this makes “perfect sense,” with non-affiliated researcher Richard B. Alley of Pennsylvania State University telling Mashable:
“Warming melts glaciers, whether the warming is caused by natural or human causes. And because glaciers are slow thermometers, even if humans were to quit warming the climate, the glaciers will lose more mass in the future as they ‘catch up’ with the warming that has already occurred.”
So what does this mean for our understanding of the glacial melt problem? Well most importantly it highlights the need to redouble our efforts to find alternative energy sources so as to cut our reliance on fossil fuels. We’re unlikely to be able to stop the glacial melt now, but this research makes clear that what we do today will be important for the situation our children and their children face in the years to come.
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