英语访谈节目:高温加速冰盖融化速度

Hari Sreenivasan: Europe broke heat records this past week. Paris recorded an all time high temperature of 108.7 degrees. That heat is now moving north toward the Arctic. Over the next few days and so-called heat dome is expected to form, raising concerns among climate scientists. They're worried about ice melt, rising sea levels and more. Washington Post reporter Andrew Freedman covers weather and climate and he joins us now from Washington DC. First a little science explainer. What's a heat dome?

Andrew Freedman: Yeah so a heat dome is basically a high pressure area, kind of in the mid to upper levels of the atmosphere that forms this kind of bubble, if you will, where the air within it is sinking and heating and weather systems around it are basically rerouted as if there was a detour in the atmosphere.

Hari Sreenivasan: Okay. So as this heat dome moves over the Arctic, we're expecting higher temperatures than normal. And then what happens?

Andrew Freedman: So we're expecting potentially exceptional melt event this week over the Greenland ice sheet that could potentially lead us to new record losses in sea ice and new record melt in Greenland and Greenland ice melt raises sea levels.

Hari Sreenivasan: Is there a cycle that this feeds into as the ice melts and the sea level rise? What happens?

Andrew Freedman: It's sort of like ice cubes floating in a glass of water. It doesn't raise sea levels but what it does is it exposes more dark ocean water to incoming sunlight which raises the ocean temperatures which in turn melts more sea ice. So there is a positive feedback there.

Hari Sreenivasan: What are scientists going to do about this? How are they planning to study this, the ripple effects of what could happen in the next week and a half, two weeks?

Andrew Freedman: Scientists are up there. They're up there on boats, they're up there on the ice sheet. But when talking to these scientists you know the sense of a system that is getting into sort of a runaway feedback really comes through. So you can tell that there is the potential for these types of events to encourage very severe impacts in to future decades and into future years.

Hari Sreenivasan: In the past couple of weeks we also saw stories about forest fires in the Arctic Circle. Does that also contribute to this feedback loop? What happens to the ash? Where that lands?

Andrew Freedman: So right now we've seen the warmest June on record, warmest July so far. It'll be the warmest July on record in Alaska. That state has seen over 2 million acres burn already this fire season. There are forest fires burning all across Siberia. This releases more carbon dioxide and other greenhouse gases which further warms the planet. And also where this ash is going, a lot of this is landing on the ice sheet. So on either Greenland or on sea ice. So when you get a darkening of the ice that obviously makes the ice less reflective which allows more heat to be absorbed which helps melt the ice.

Hari Sreenivasan: All right these are all big cycles that we're talking about. Washington Post reporter Andrew Freedman joining us from Washington D.C. Thanks so much.

Andrew Freedman: Thanks for having me.