A very good NPR Science Friday interview with some leading ocean scientists.Changing Climate Means Changing Oceans
Scientists who study the oceans say the effects of climate change are already being seen in the world’s oceans. From acidification and warming temperatures to sea-level rise and sea-ice loss, Ira Flatow and guests look at how the oceans are changing with changes in climate.
FLATOW: When you hear the words climate change, chances are you think about its effects on the land, right, and talk about drugs and crops and glaciers. But some scientists say we shouldn’t be calling it climate change. We should be calling it ocean change, because the oceans are, literally, choking, they say, on greenhouse gases.
They’re becoming more acidic. There are changes in ocean circulation patterns, fisheries, corals, plankton, shellfish. They are all being affected by the changing water.
There’s also more water in the oceans than ever before. Sea level is rising as polar ice and glaciers are melting, and even the water itself is expanding as it warms up.
So what does that mean for those that live on islands or along the coast? Rising oceans? That’s what we’ll be talking about today. We’re broadcasting from a conference of the National Council for Science and the Environment. Our changing oceans is the theme of the conference, and we’ll be talking about our changing oceans this hour….
FLATOW: Mm-hmm. Steve Gaines, your research is in fisheries management, and I talked about at the beginning ocean levels rising. Sea levels are rising. How are fish populations affected by all of this climate change?
Prof. GAINES: Well, surprisingly, about 20 percent of the protein that people eat comes from the sea. I think most people don’t think it has — it’s anywhere near that high. And climate change is going to have a big impact on that, because when species move towards the poles, it changes the types of fish you can catch in one place.
When warming reduces the productivity of the ocean by making phytoplankton be more nutrient-limited in parts of the ocean, it makes the food webs that depend upon that phytoplankton decrease in abundance. And so there’s potential for fairly dramatic declines and rearrangement of where the fish occur….
NEREM: … And then there’s — you know, we’re looking at projections for the future, and there’s a lot of people now who are thinking that a meter by 2100 is well within the range of possibility.FLATOW: What is the range of possibility?
Prof. NEREM: Well, that’s the big question. That’s where all the research is right now. It’s what people are looking at. You know, a meter is in that range, but from 80 centimeters up to a meter and a half is probably a good bet.
FLATOW: And could something happen to accelerate that, unexpectedly? Could we have more ice melting in Greenland or Antarctica or something?
Prof. NEREM: Well, definitely. It’s, you know, the components of sea level change are really similar to expansion, which is about a third of what we have right now. Mountain glaciers outside of Greenland and Antarctica are another third. But that’s really the big ice sheets that have the most water locked in them, and we have six meters of potential sea level rise in Greenland, 60 meters in Antarctica. And that’s where, you know, the potential for something that we didn’t anticipate could happen sooner than we think….
Prof. NEREM: There are thinking very creatively about a lot of aspect of geo-engineering climate where — but most of them are like this proposal, where -even if they work — all they do is deal with one of the symptoms of climate change. And the unintended consequences in a scenario like that, of course, would be really dramatic. But, I mean, there are lot of different geo-engineering scenarios that have been put on the table to, you know, paint roads white and rooftops white, and things on these lines, which can deal with some of the cooling aspects and heating aspects. But they don’t solve all of the problems.
FLATOW: And so, what would be one that had the best effect, do you think, if you wanted to think of one. Would it be capping greenhouse gas emission? Would it be…
Prof. NEREM: Well, I mean, I think, in the long-term, we need a budget for carbon that we’re putting in the atmosphere. And a budget that sets caps, and then pretty drastic reductions and a mechanism of driving those. And there are a number of proposals in the NRC report as to different options about how you could get there.
- Nature: “Global warming blamed for 40% decline in the ocean’s phytoplankton”: “Microscopic life crucial to the marine food chain is dying out. The consequences could be catastrophic.”
- Science: Vast East Siberian Arctic Shelf methane stores destabilizing and venting: NSF issues world a wake-up call: “Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming.”
- Nature Geoscience study: Oceans are acidifying 10 times faster today than 55 million years ago when a mass extinction of marine species occurred
- Geological Society: Acidifying oceans spell marine biological meltdown “by end of century”
- New study of Greenland under “more realistic forcings” concludes “collapse of the ice-sheet was found to occur between 400 and 560 ppm” of CO2
- Climate researcher: “It is my assessment that we have had the strongest melting since they started measuring the temperature in Greenland in 1873.”
- Sea levels may rise 3 times faster than IPCC estimated, could hit 6 feet by 2100