美国国家公共电台 NPR--How ocean water vapor may be an answer to a climate change issue（在线收听）

How ocean water vapor may be an answer to a climate change issue

Transcript

Only 2.5% of the Earth's global water supply is fresh water and supplies are shrinking with the unrelenting advance of climate change. Researchers say ocean water vapor may provide relief.

DWANE BROWN, HOST:

Of all the water on Earth, only about 2 1/2 percent is fresh water, and it's also vanishing fast due to climate change.

LEILA FADEL, HOST:

But researchers at the University of Illinois at Urbana-Champaign say climate change is also creating fresh water in the form of ocean vapor.

PRAVEEN KUMAR: And if we could tap into that resource, we could supply fresh water without the need to desalinate.

BROWN: Praveen Kumar is a professor who specializes in climate-driven changes in the water cycle. Kumar says existing methods to meet freshwater demands, like seeding clouds to make rain or removing salt from seawater, are inadequate and unsustainable.

FADEL: So as global temperatures keep rising, his research team set out to find a long-term solution.

KUMAR: Warmer air holds more moisture. We're also looking at warming of the ocean's surfaces. And as a result, evaporation will increase. So essentially, more evaporation and more moisture in the air and, therefore, more water.

BROWN: Now, the study focused on 14 water-stressed cities around the world. The objective - to see whether it would be feasible to capture ocean vapor and turn it into fresh water.

KUMAR: What we envision for this work is a capture surface. So if you think about putting something, say, in the ocean west of Los Angeles, with about 9 to 10 such structures meeting the entire drinking needs of the Los Angeles population.

FADEL: The researchers say what they need next is some kind of apparatus to make this happen.

KUMAR: It is now feasible to approach it from an infrastructure and a large-scale investment perspective and solve the problem.

BROWN: Kumar says capturing moisture from over the oceans could provide a sustainable fresh water supply and solve one of the planet's great challenges.