NOEL KING, HOST:
This week, scientists published new evidence that melting ice caps in Antarctica and Greenland are on track to cause the sea to rise by more than a foot this century. That's if people keep pumping greenhouse gases into the atmosphere at the current rate. For the first time ever, scientists calculated ice melt from every single glacier on Earth, from the Andes to the Himalayas to Alaska. And estimates show that glaciers are losing about 267 gigatons of ice every year. Our co-host, Rachel, talked to one of the study's authors, Bob McNabb.
BOB MCNABB: Our study says that over the past 20 years, glaciers have contributed about a fifth of the observed rise in sea levels that we have seen over that same time period. And not only have we seen that glaciers have lost quite a bit of mass over that time period, but they have also been losing mass at an accelerating rate.
RACHEL MARTIN, BYLINE: How many glaciers are we talking about?
MCNABB: Over 220,000.
MARTIN: Wow. So obviously, human-produced greenhouse gas emissions are driving the melting. But if we were to just magically go to zero on gas emissions right now, would that bring back the glaciers?
MCNABB: Most likely not. So we know that it takes glaciers time to adjust to a change in climate. So what they're reacting to right now is a little bit the recent changes in temperature, but also changes in temperature a bit further back in time. So if we were to magically stop all of our emissions tomorrow, it would still take some time for them to adjust to this new climate that we have put them in.
MARTIN: What does that mean? Can you draw a direct connection between what happens when we lose glaciers and its effect on human life?
MCNABB: Sure. So in a lot of regions, we know that glaciers are extremely important for water resources. So in places like High Mountain Asia, in places like the southern Andes, these are very important water resources. And as they disappear, we see lack of water translating into problems with food production. And in other areas, glaciers are extremely important for nutrients. So they provide a lot of nutrients to rivers and eventually to the ocean. And so losing them can also have an impact on ecosystems.
MARTIN: What are the policy recommendations, if any, around melting glaciers? I mean, if we've established that the harm has basically been done and they're disappearing rapidly, what's to be done about it?
MCNABB: Well, I don't want to say that the harm has been done because all of the choices that we make will have an impact on the future. So the changes that we make today, even if they seem like they might be small, will have an impact. So it's more of a question of, how much of an impact do we want to have in terms of bringing down emissions, in terms of slowing down the melt rate, in terms of bringing down the increase in temperatures?
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KING: That was Bob McNabb talking to our co-host, Rachel. He is a lecturer of geography and environmental sciences at Ulster University in Northern Ireland, and his research is in the journal Nature.
(SOUNDBITE OF SEAS OF YEARS' "CEASING BRIDGES") Transcript provided by NPR, Copyright NPR.