Quickfire Quiz: Mark Serreze
The director of the National Snow and Ice Data Center in Colorado talks exclusively to TRANSFORM about his ‘front row seat’ to changes in the Arctic’s sea ice.
How has the Arctic changed since you first visited, back in 1982? I was there before things really started to change, when it still looked like the Arctic of old – the Arctic that the explorers of the past would have been familiar with. We have since seen this tremendous decline in sea ice cover in just a short space of time; the ice caps I once studied as a young graduate are now gone. What is really visceral is when you go somewhere like Point Barrow, Alaska, at the end of summer and look north – all you will see is open ocean as far as the eye can see, in a place where the ice used to come very close to the shore. Now it’s just endless open water, and it’s that kind of thing that really hits me.
You once predicted the Arctic would be ice-free by 2030 – do you stand by that? I said that in 2007, which was a watershed year: we recorded the lowest sea ice extent ever, blowing away the previous record. It removed any shred of doubt about what was going on. There is a growing view within the scientific community that we could be looking at a seasonally ice-free Arctic somewhere in the mid 2040s, but I am going to stick with 2030, give or take a few years. We have already lost something like 40% of the ice cover we had in the early 1980s. It has been a remarkable reduction and there is no evidence that it is going to stop.
What are the ramifications, should your predictions come true? We are already seeing the impact it is having on life up there, on polar bears and seals, for example, which use the ice as a platform for travelling. But the big thing is whether losing sea ice can influence weather patterns in lower latitudes. The sea ice acts as a ‘lid’ for most of the year, separating a cold atmosphere from a warmer Arctic ocean, but once you have removed that cover, all that heat from the sea can go into the atmosphere. We have observed temperature rises in the Arctic that are much greater than in the northern hemisphere as a whole, and this could be messing with the global weather system. The loss of Arctic sea ice is probably the single most prominent signal of climate change on the planet.
You were once a sceptic when it came to human influence on climate. Yes – we saw these changes emerging, but it looked like some sort of natural cycle to me for a long time, and I wasn’t convinced. It was never a question of the physics or whether greenhouse gas concentrations in the atmosphere would cause warming, I just wasn’t sure we had witnessed it yet. I believed greenhouse warming was still open to debate as late as 2000, so I was a bit of a latecomer – but as scientists we are supposed to be sceptical, and I certainly was for a long time.
Was there a ‘eureka’ moment, where you changed your mind? I would like to say there was, but it was just the overwhelming weight of evidence. We saw the Arctic changing in the 1990s, but a lot of it looked like a natural cycle. As the years continued to pass, the evidence that we were looking at something more than natural variability started to grow, and it was probably in 2003 that I changed my mind. However, there is still conflicting evidence that scientists are trying to understand – we don’t know everything.
Does that conflicting evidence put any doubt in your mind about humanity’s impact on climate change? Oh, no. The way I look at it is this: imagine painting a picture with a broad brush. You see the outline of what is happening but you are missing the details, and some of those can be important and can come back to bite you. We know where things are going – the Arctic is going to continue to lose its sea ice cover, that’s certainly going to have a lot of important ramifications – but what are the surprises that we haven’t foreseen? That is what a lot of people are concerned about, the known unknowns. We know the broad picture absolutely.
Read more about Mark’s experiences and work in his book, Brave New Arctic: The Untold Story of the Melting North
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