I'm William Rangham, and this is Horizons.

The world's ice is melting faster than previously thought,

and it's threatening our planet with potentially massive sea level rise,

weather disruptions, and further global warming.

Next up, why researchers are studying the so-called doomsday Glacier and what it tells us about the fate of ice on Earth.

Welcome to Horizons. As we continue to warm the planet, we keep breaking temperature records.

The past decade was the hottest decade in recorded history. We've also seen the cascading disasters that are made worse with each fraction of a degree of warming. Fires in California,

floods across India and Southeast Asia, devastating hurricanes in the Caribbean. What we don't

pay nearly as much attention to is what climate change is doing to the colossal amounts of

ice on the top and bottom of the world.

The ice up in the Arctic and down on Antarctica play some critical roles in maintaining

life on Earth. That ice helps steer our planet's ocean currents, which are major drivers

of our weather. They're the biggest reservoirs of fresh water on Earth. But if enough of that ice melts, sea levels could rise all over the world.

So we're going to look at today at the fate of ice on Earth.

And we're going to start in Antarctica.

Our colleague, PBS NewsHour science correspondent Miles O'Brien, is just off the west

coast of Antarctica, and he joins us now.

Miles, so nice to see you at such a distance.

For those who didn't see your terrific report on the news hour this week, explain to us, where are you right now, and why are you there?

William, I'm very near the Thwaites Glacier,

which is probably the most consequential piece of ice

on the planet.

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