Ice caps on both poles of the planet
are melting.
And not just a few.
All of them.
If all this ice melted,
it would be catastrophic.
Sea levels are rising around the globe
at around 4.8 mm (0.19 in) every year.
Glaciers and ice sheets
are melting due to global warming.
And climate scientists estimate
that the average temperature on Earth
could increase
from the current 14 °C (58 °F)
to 27 °C (80 °F).
At this pace, you would witness
devastating floods on coastal lands.
And parts of the world would be
entirely lost to the sea.
But if all the world’s ice melted away,
things would go south fast.
Since we're talking about ice,
let’s start with a cold, hard fact.
If all the world’s glaciers
and ice sheets melted,
sea levels would rise
an astonishing 65 m (213 ft).
All over the world, countries with
an elevation below this level
would cease to exist.
Farewell to the Maldives,
Singapore and Denmark.
Sorry you never got to visit them.
The 37 million people living in those areas
would have to evacuate
and head for higher elevations.
And fast.
And a lot of the populated coastlines
around the world
would have to be evacuated too.
In North America, the entire
Atlantic seaboard would vanish.
That means Disney World in Florida
wouldn’t be a small world.
It would be an underwater world.
On the West Coast,
the hills of San Francisco would become
a cluster of islands.
And the Golden Gate Bridge
would stick out from the sea.
Until it rusts away and
disappears into the ocean.
Millions of people in the U.S.
would lose their home
and move further inland.
If you live in Denver, Colorado,
your home city might be bustling.
In South America,
the Amazon and Paraguay River basins
would become inlets for the Atlantic Ocean.
And big urban centers
like Buenos Aires or Montevideo
would disappear.
Europe would say goodbye to
many of its cities.
Venice would become
a modern-day Atlantis.
And London’s Big Ben
would now strike midnight
from underwater.
Large parts of Asia would be devastated
by the swelling seas
Nearly 800 million people would
lose their homes in China,
India and Bangladesh.
Australia could become more hospitable
as an inland sea develops.
But it would be bad news
for the 80% of Australians
living on the coastal strip.
You'd be the lucky one
if you lived in Africa,
where large parts of land
would be spared from global flooding.
Unfortunately, the world would lose
one of the ancient wonders,
the Great Pyramid of Giza.
It would be swamped
by the Mediterranean.
But flooding of the continents
would only be the tip of the iceberg.
The world would also lose
90% of its freshwater.
This is how much is stored
in the Antarctic ice sheet.
This ice water would mix with the ocean
and dramatically disrupt its salt levels.
Many aquatic animals that have evolved
to live in saltwater would go extinct.
Diluted water would also impact
the ocean currents.
The Gulf Stream,
which brings warm air to Northern Europe,
would become weak or even stop.
And this would make temperatures
plummet in that region.
And there's more bad news.
The glacial freshwater stores
some toxic chemicals like DDT,
and the Arctic permafrost
has as much mercury as
everywhere else on the planet combined.
As these toxic chemicals and elements
ended up in rivers, lakes
and groundwater reserves,
they would poison many people.
The melting of permafrost would also
be a feast for microorganisms
that feed on the organic matter
frozen inside.
These organisms will, pardon my French,
fart out a lot of greenhouse gases
that could cause a global
temperature rise of 3.5 °C (6.3 °F).
Most of life on Earth
would not survive this disaster.
But I have good news for you.
Scientists estimate
that all of the Earth's ice
wouldn't melt overnight.
If climate change keeps going
at the same rate,
it will take 5,000 years.
But if we begin to make serious changes
to our climate policies,
maybe we could avoid it altogether.
We could, for example,
start with refreezing the Arctic.
But that's a story for another WHAT IF.