Can we halt Arctic melt? Hard question for UN advisor
I had a very interesting high-profile visitor here at Deutsche Welle this week. Bonn, John Le Carré’s “Small Town in Germany” is this country’s UN city nowadays, home to organizations like the climate secretariat UNFCCC and the Convention on Migratory Species, CMS. This year marks 20 years of the former German capital in that new UN role. Fortunately for me and my colleagues, it brings a lot of interesting people to the city.
The University and the City of Bonn have been running a series of lectures by members of the Scientific Advisory Board of the United Nations Secretary-General Ban Ki-Moon this year, under the heading “Global Solutions for Sustainable Development”. This week, it was the turn of Susan Avery, who was President and Director of the Woodshole Oceanographic Institution in the USA until last year. She has been on the advisory board to Ban Ki-Moon for the last three years and she and the other advisors are just finishing their report, so it was great to have the opportunity to talk in length.
Sea and sky as dancing partners
Her lecture was about the importance of the ocean with regard to climate, but she also talked to me about a whole range of ocean-related issues in an interview to be broadcast on our Living Planet programme, starting next week.
Susan Avery is an atmospheric scientist, (the first to head a major oceanographic institution, she told me). She has a very attractive image to describe how the atmosphere and the ocean relate to each other:
“In our planetary system we have two major fluids, the ocean and the atmosphere, and think of them as two dance partners… moving along, but in order to get a choreographic dance, they have to talk to each other. They do that through the ocean-atmosphere interface, which is wave motion, spray, all the things that help them communicate. These two create different dances… an El Nino dance, or a hurricane dance, for example. In reality what they do together is transport heat, carbon and water, which are the major global cycles in our planetary system.”
Since the onset of industrialization, we humans have been introducing some different steps to the dance, it seems:
“When you take it to the climate scale, we talk a lot about the temperature of the atmosphere, increases associated with the infusion of carbon, that is human produced. The thing is that the extra carbon dioxide that gets released into the atmosphere through our fossil fuels and deforestation is associated with extra heat. Of the carbon dioxide we release into the atmosphere, half will stay in the atmosphere, 25% will go into the ocean, 25% will be taken up by the land. But if you look at the heating or warming, 93% of the extra warming is actually in the ocean. There are only very small amounts in the atmosphere.”
Centuries of warming pre-programmed
That means a huge amount of heat is actually being stored in our seas:
“And you can understand why, because the atmosphere is a gas, the ocean is a mass of liquid, which covers two thirds of our planet, and it has a huge heat capacity to store that, but that heat doesn’t just stay at the surface. So (..) when you only talk about heat and temperatures at the surface, you’re ignoring what’s happening below the surface in the ocean, and once the ocean gets heated it’s not going to stay there, because there is this fluid motion. So we’re getting to see greater and greater temperature increases at greater and greater depths. And once that heat gets into the ocean, it can stay there for centuries. Whereas in the upper ocean, it might stay 40 or 50 years, when you get into the deeper parts, because of the density and capacity, it stays there for a long time.”
So, she explained, the carbon dioxide we’ve put into the atmosphere already – and the heating associated with that – means that “we’re already pre-destined for a certain amount of global temperature increase. Many people say we have already pre-destined at least one and a half degree, some will say almost two degrees.”
Now if that is not a sobering thought.
And on top of that comes the acidification of the oceans caused by the extra carbon dioxide, which is playing havoc with coral reef systems and shell-based ocean life forms.
“This is really critical, because it attacks a lot of the base of the food chain for a lot of these eco-systems”.
“What’s in the Arctic is not staying in the Arctic”
Susan Avery’s work has included research on the Arctic and Antarctic, so of course I took the opportunity to ask how she sees all this affecting the polar regions.
She explained how the rapid increase in ice melt in the Arctic – both sea-ice and land ice – caused by atmospheric warming above and warmer ocean waters below, is of great concern for two reasons. The more obvious one is the contribution of land ice melt to sea-level-rise. The other, she explained, is that the melting of the land-based ice results in “a freshening of certain parts of the ocean, so particularly the sub-polar north Atlantic, so you have a potential for interfacing with our normal thermohaline circulation systems which could dramatically change that.” The changes in salinity currently being observed, are a “signal that the water cycle is becoming more vigorous”. This, of course, has major implications for ocean circulation and, in turn, the climate, not just in the region where the ice has been melting:
“What’s in the Arctic is not staying in the Arctic. What’s in the Antarctic is not staying in the Antarctic. I would say the polar regions are regions where we don’t have a lot of time before we see major, massive changes”.
What I find particularly worrying is that Susan Avery confirmed there is still so much we do not know about what is happening in the polar regions and in the ocean in general.
“We really need to get our observations and science and models working together”, she told me. “The new knowledge we have created on processes in the Arctic has to be incorporated into climate system models”.
Paris and the poles
So, given that temperature rise of 1,5 to two degrees Celsius could already be a “given”, and the Arctic is being affected much faster and more strongly than the planet on average, is there any real hope that we can hold up these developments and halt the melting of ice in the Arctic? This was clearly a very difficult question for my guest. She told me she had been very relieved that the Paris Climate Agreement was signed and was sure humankind could still “make things better”. But when I asked whether we will really be able to reverse what is happening in the Arctic or halt climate change in the Antarctic, this was what she replied:
“I don’t have an answer, to be honest. I think we’re still learning a lot about the Arctic and its interface with lower latitudes, how that water basically changes circulation systems, and on what scale. But I think what’s really critically needed right now to get a better sense of the evolution of the Arctic, and of sea level rise, is a real concerted observing network. We know so little, about the Arctic, the life forms underneath the ice. We have the technology. What I really see now is a confluence of new technologies, new analytical approaches, new ways to do ocean science, and all it takes is money to really get those robots there, get the genomic studies that you need, the analysis. We are at the stage where we can do so much, to further our understanding, and I would really put a lot into the Arctic right now, if I had the money to do so.”
Me too, Susan.
Ice: the final frontier?
This brings us back to a key problem I have worried about ever since I started to work on how climate change is affecting the Arctic. That change is speeding up so fast, it is virtually impossible for our research to keep pace. As Susan Avery put it:
“The Arctic will be a major economic zone, we’ve already seen the North-West Passage through the Arctic waters, we’re going to see migration of certain fisheries around the world – and we don’t even know completely what kind of biological life we have below that ice. We have the ability to get underneath the ice now. I call these the frontiers, of the ocean, and that includes looking under ice.”
I am reminded of my trip on board the Helmer Hanssen last year, accompanying a research mission to find out what happens under that ice and down in the deep ocean during the cold, dark season.
(Listen to the audio feature here). There is still so much we do not know about life in the ocean – and it might disappear before we even knew it was there.
DateJuly 8, 2016 | 12:07 pm
TagsArctic, Avery, Ban Ki-Moon, Bonn, Climate, Emissions, ocean, ocean acidification, science, Sea level, UN, Universität Bonn, Warming, Woodshole