What this summer’s record-breaking heat means for global sea level rise

What this summer’s record-breaking heat means for global sea level rise


JUDY WOODRUFF: Now: melting away before our
eyes. As the scorching heat wave that stifled Europe
last week moves north, William Brangham reports on how it is setting records in new and alarming
ways. WILLIAM BRANGHAM: That’s right, Judy. The same weather pattern that set records
in Europe is now over Greenland, where temperatures are running as much as 15 to 20 degrees Fahrenheit
above average. Greenland is home to one of the biggest ice
sheets on Earth, second only in size to Antarctica. And researchers say some 60 percent of it
now showing signs of surface melting of at least one millimeter. That doesn’t sound like a lot, but that means
10 billion tons of ice is being melted in a single day, sending a torrent of meltwater
into the oceans. To help us understand what’s going on here,
I’m joined by Ted Scambos. He’s the senior research scientist at the
Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder. Ted Scambos, thank you very much for being
here. Can you just give us a sense of how significant
this melting is in Greenland right now? TED SCAMBOS, University of Colorado Boulder:
Well, we haven’t seen melting like this in 150 years, except for the year 2012. And it looks like 2019 is actually going to
break that record in terms to have the amount of melting that is coming off of Greenland. We’re seeing a lot of runoff from the sides
of the ice sheet. And that, of course, adds to this river flow
that goes into the ocean eventually. It’s really quite dramatic and the biggest
that we have seen, as I said, in about seven years. But prior to that, it’s been over 150 years
since the very top of Greenland has melted. WILLIAM BRANGHAM: This is really sea level
rise happening right before our eyes. And we know that there are two ways that the
ocean warms up, where the warmer climate warms ocean water. That expands. And it rises. But the other is what we’re seeing here in
Greenland, right? TED SCAMBOS: Absolutely. And this is going to add several billion tons
to the ocean. Meltwater from Greenland is going to contribute
probably close to a millimeter of sea level rise in just this summer alone. Twenty years ago, I would have said it’s probably
not contributing anything to the ocean. So you can see that we have really changed
things up there. And, of course, what happens 20 years from
now, 50 years from now is a big question mark. WILLIAM BRANGHAM: So, if someone is out there
hearing you say this, and they think, well, a millimeter to the ocean, how much is that,
really, like, can you help us understand that in the scale of the things that we worry about
for sea level rise globally? TED SCAMBOS: So, a millimeter per year just
from Greenland. And then you mentioned that the oceans are
getting warmer, so they’re expanding. Antarctica is also in the mix of this contributing
another fraction of a millimeter. All of these things are faster now than they
were just a few decades ago. And the concern is that the rate is going
to keep going up and at a faster and faster rate that will actually accelerate. A millimeter may not sound like much. Small amounts of sea level rise have a big
impact on very low-lying, very flat areas. If you talk to Miami, New Orleans, Houston,
they’re concerned about an inch or two over the coming decades of sea level rise, because
it means higher storm surges, and it means flooding and changes in groundwater right
now. So it is a big deal. And the most important point is that it wasn’t
there 20 or 30 years ago. And we know that the forecasts are showing
that we’re going to see a lot more of this in the future. WILLIAM BRANGHAM: And it just so happens that
we have built billions and billions and trillions of dollars worth of infrastructure along those
coasts. TED SCAMBOS: Tremendous amount of infrastructure. And, of course, that requires ensuring. That requires investment. All of these things are, in a way, at risk
if we continue to allow the Earth to warm up in an unbridled way and change the coastline,
basically. WILLIAM BRANGHAM: All the climate models have
really predicted what we are seeing now, these increased storms, increased droughts, increased
heat waves. We are seeing this over the past year-and-a-half,
so many of these different signals. Do you think that we’re getting to the point
where this is building a genuine consensus that action is required? TED SCAMBOS: Yes, I think there’s nothing
like reality to convince people. You can talk all you want about models and
about future forecasts, that things are going to happen a long distance away. Having things happen vividly on TV shows,
the news, in the newspapers, all of that helps bring people to the point that things are
really changing. And although we thought we might be able to
wait a while, in fact, we’re probably on the cusp of seeing real changes that would bring
these things home to roost, basically, in terms of weather changes, as I said, coastline
changes, changes in the amount of drought or heavy rains. All those things have a major and costly impact. And so people, I think, will begin to decide
that a long-term commitment to action is what’s needed. WILLIAM BRANGHAM: As I’m sure you have been
hearing, there are — this — the concern over climate change and the urgency for action
has started to bleed even into the presidential race. And there has been talk about, we need to
act by 10 years, 12 years. For people who might not understand what people
mean when they say we have to act in a decade or 12 years or 15 years, help put that into
perspective. What does that really mean? TED SCAMBOS: Well, it really means that we
need to start changing how we produce energy. And I think trying to there to carbon-neutral
within the space of a decade probably a bit too much to ask. But the tools are all there for us. The technology is there, in terms of solar
panels and wind farms, in terms of conservation, electric cars. We can explore things like biofuels. We need to consider nuclear, perhaps, in terms
of a power source. It’s all in the mix. We know how to do it. And what’s more is, people are going to make
money bringing us this future of energy generation. It’s actually, I think, going to be quite
easy, as soon as we say, as a nation, collectively, individually, city by city, state by state,
that we’re going to commit to doing these things. And I’m really pleased to see how many states
and cities have set a goal for themselves in the future. I’m actually really confident that, in fact,
the U.S. is going to lead the way on all of this, because we have such a strong entrepreneurial
spirit about solving problems once we’re convinced they’re a problem. And that’s what I think the future holds for
us. WILLIAM BRANGHAM: All right, Ted Scambos,
University of Colorado Boulder, thank you very much. TED SCAMBOS: Thank you.

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