From thin and wispy to big and puffy,
clouds cover about 70% of the planet at any given moment.
But what if, in the next minute,
poof, they all disappeared?
That instant might shock onlooking astronauts
on the space station.
But someone who is, say, hiking in the desert
wouldn't know right away that things on Earth
were about to get really bad.
Within a few days, though,
the first warning sign would show up: humidity.
It'll be even worse if you live by the coast.
Normally, the sun's heat evaporates water,
mostly from the ocean,
and that water vapor is condensed into clouds.
But if clouds are cut out of the Earth's water cycle,
that water just hangs around in the air,
creating close to 100% humidity.
If you were to get on a flight,
you might experience more turbulence than usual.
Without the protective cover of clouds
to bounce sunlight into space,
the sun will heat the Earth more,
creating more rising, uneven hot air.
But a bad flight may be the least of our worries,
because there'll be no more rain
or snow or even a light mist,
and that means there won't be any way
to replenish the water sources we drink from,
like lakes, streams, rivers, springs, and aquifers.
So once last winter's snow melts,
we're stuck with whatever water we have on hand.
And the clock is ticking.
If the world were to keep up
its current water-consumption rate,
we would drain all of the freshwater lakes and rivers
in about 23 years.
So to conserve our freshwater supply,
humanity will have to be strategic.
Today, the average American uses
about 80 to 100 gallons of water every day.
But saving ourselves is going to take more
than just skipping long showers and laundry.
The water we use in our home and public places
accounts for only 21% of our water usage.
The two biggest demands are actually
thermoelectric power to generate electricity
and irrigation for farms.
Not only do power plants use tons of water,
ones that run on nuclear fuel could spell disaster
if their water-cooling towers run dry.
The 2011 Fukushima nuclear disaster, for example,
was set off when an earthquake knocked out power
to its water-cooling pumps.
And farms are going to need even more water
without the help of a good rain.
This permanent drought would kill
tons of wild vegetation and animals as the land dries up.
Within a few years,
eroding soil may kick up giant dust storms
like the Dust Bowl in the 1930s.
Meanwhile, Earth's climate will be going haywire
without clouds.
It's hard to say when this will all happen
without some very expensive climate modeling,
but cloud expert Chris Fairall
did offer some quick back-of-the-envelope calculations.
Without clouds, average surface temperatures
would rise by as much as 22 degrees Celsius.
This extreme temperature spike
would not only destroy the habitats of most flora and fauna,
killing off whatever survived the drought,
it would also melt the polar ice caps
and cause massive flooding of coastal cities.
You might end up being part of the 40% of the world
that would be forced inland,
and your new home might soon be in an endless desert
as seawater starts seeping into
our fresh and precious groundwater.
Sounds alarming, but there are some silver linings
to a world without clouds.
No more devastating hurricanes and tornadoes,
or delayed flights because of stormy weather,
or cloudy skies to ruin your stargazing.
As the water supply dwindles,
we'll have to make some hard choices,
but, hey, humans are creative.
We could invent ways to desalinate ocean water
or collect all that water vapor from the air.
And the sooner we do it, the better,
because in reality, we're already losing clouds.
Unprecedented levels of CO2
and the warming oceans and atmosphere
are all causing clouds to thin out.
So despite the silver linings,
it might be best to reduce our greenhouse gas emissions
and try to avoid this scary new world entirely.