you can light it on fire.

But it's not the water that's flammable,

it's actually what's bubbling up from the lake floor.

These aren't your average lakes.

They're called thermokarst lakes

and they're filled with highly flammable methane gas.

During the summer the gas bubbles to the surface

and enters the atmosphere.

But in the winter the bubbles get trapped under the ice.

So when you stab the frozen surface, it releases pockets

of the gas that you can then light up.

It may look like a fun party trick but there's more to this

effect than meets the eye.

Methane isn't just highly flammable,

it's also a potent greenhouse gas.

25 times more efficient at trapping heat

than carbon dioxide.

And these methane filled lakes are popping up everywhere

in Alaska and Siberia.

In 2017 alone 200, new thermokarst lakes

were photographed in Siberia.

So where are they all coming from?

They're actually remnants from the last Ice Age.

Around 11,000 years ago these areas

used to be frozen soil and ice.

We call these frozen underground layers today, permafrost.

But it's not permafrost that's the problem,

it's rising global temperatures which is causing

the permafrost to thaw for the first time

in thousands of years.

Since the 1980s, permafrost in Alaska

has warmed by one and a half degrees Celsius.

Almost twice as much compared to how much it warmed

between 1880 and 1980.

And when permafrost thaws, it weakens the ground above it

which can destroy roads, damage building foundations,

and even split a tree in two.

In the process, it releases a buffet of long dead plants

and animals on the lake floor.

And that's where the real trouble starts.

Tiny microbes called mathanogens eat the dead matter

and produce, you guessed it, methane.

And the more lakes that form means more ancient food

for microbes and ultimately more methane

that reaches the atmosphere.

Overall, thermokarst lakes are estimated to emit

3.8 teragrams of methane each year.

Increasing annual methane emissions by up to 63%.

And what if all of Earth's permafrost thawed?

Researchers estimate it will release at least 100 teragrams

of methane into the atmosphere, potentially warming

the planet enough to cause sea levels to rise

anywhere from three to 10 centimeters.

For comparison, sea levels have risen just 7.6 millimeters

on average over the last 15 years.

Contributing to 1.8 billion dollars in annual damage

off the coast of New Jersey alone.

But right now little is being done to slow the formation

of thermokarst lakes around the globe.

And if you burn the methane as it bubbles to the surface,

it can reduce the greenhouse effect but only slightly.

Since lighting it on fire turns it into carbon dioxide

and water vapor, two other potent greenhouse gasses.

In the end, it's up to us to reduce our own emissions.

Because lighting lakes on fire isn't going to be enough.