and you don't know what kind of weather is waiting for you outside your tent.

It doesn't matter anyway.

In rain, hail, sleet, snow, or blistering heat,

you're on the front lines, shovel in hand, wearing over 20 kg (50 lbs) of gear,

battling against nature to save the environment.

On a good day, you might plant 2,000 trees in a 10 hour shift.

But imagine if you had to do this every day for the next 570,000 years...

This is 'What If,'

and here's what would happen if we planted one trillion trees.

It's true, tree planting is no picnic.

Up north, it wouldn't be uncommon for a tree planter

to pee on their own hands to keep them from freezing.

Tree-planting is undoubtedly one of the world's hardest jobs.

So why would anyone do it?

Because if they didn't,

life would be much worse... for everyone.

Since 1900, Earth's average temperature has risen by one degree.

That doesn't sound like much, but just wait 'til you feel it.

If our planet becomes just two degrees hotter than it was in the 20th century,

heat waves, flooding, crop failure, and animal extinction will be common place.

Doing nothing about it would just be reckless,

demonstrating an extreme indifference not just to human life, but to all life on Earth.

You might even call it,

second degree murder.

Some ideas that have been put forward for cooling the planet

include a giant space umbrella to shield Earth from the Sun,

or a giant space mirror to reflect sunrays back into space.

Meanwhile, back on Earth, we've already got trees

that absorb the harmful carbon emissions that warm our planet,

while also expelling oxygen so that we can breathe.

Problem is, we just don't have enough of them to do the job.

While the world is currently home to roughly 3 trillion trees,

we lose about 10 billion of them every year.

And as you might expect, we've become more efficient

at stripping our forests than we are at replanting them.

If we planted a trillion trees, we could offset a decade's worth of those emissions.

Time that we desperately need.

But it will truly require an international effort to realize this goal.

If every human on earth planted just 150 trees,

we could meet our 1 trillion tree goal quite easily.

But that's just not very realistic...

And while the world's tree planters work long, hard days to pick up the slack,

there still aren't enough of them to get the job done in time.

A study at Yale University concluded that

if we continue our current rate of deforestation without planting more trees,

our planet will be completely treeless within 300 years.

Before we re-visit the space umbrella idea,

let's consider some of the more feasible options that are on the table.

Tree planting drones, for example, can plant up to 100,000 trees a day,

the equivalent of about 50 veteran tree planters.

And while a lot of students take up tree planting as a lucrative summer job,

the more innovative ones have found other ways to cash in.

But whether we do it by drones or by robots,

it's time to bring out the big guns in this battle for our planet.

Planting a trillion trees is still far ahead in our future,

but do you know what our world would look like without them?

Well that's a story for another 'What If.'