This is an air conditioner.
Here's a group of them.
It's also a water filter,
an air purifier,
a bike rack, a stimulus package,
a therapist, a shamwow,
crime stopper, noise reducer,
traffic calmer, and
oh right, a tree!
Let me explain.
There are a lot of trees in the
Halifax region.
How many? Maybe a thousand?
Maybe a hundred thousand?
Well, try 52 million.
Put together, all those trees are part of
what we call the Urban Forest.
In fact, the municipality has a 442 page
long document about this,
called the Urban Forest Master Plan
and if you're wondering why we need
442 pages for, um, trees?
You've come to the right place.
Because, as it turns out,
trees aren't just pretty things to look at.
They actually provide many
important benefits.
For example, air purification.
In a city, the air can easily become
polluted, whether that's from
industrial activity, or even just
traffic from the streets.
Now, one way to make sure our air is clean
and breathable is to
purify it with cool things like
the smog free tower.
It sucks in pollutants from the air,
turns it into rings, and
costs just $54,000 each.
Or, you could plant a tree
because trees are experts at
cleaning the air.
They trap airborne pollutants
with their leaves and
take in carbon dioxide
through photosynthesis.
In total, we estimate trees in Halifax
trap 1478 metric tons of pollutants
every year.
So next time you're, I don't know,
breathing?
You can thank a tree for that.
Here's another benefit.
Trees are cool to be around.
Literally.
Yea, they provide shade for people
and nearby buildings
but they also cool through a process
called evapotranspiration.
On a hot sunny day, trees are
releasing water into the atmosphere,
cooling the air around them
and that is crucial for a city.
You see, urban areas have a lot of
surfaces that either create heat
or reflect heat and that
usually means that cities are hotter
than their surroundings.
A phenomenon know as the
Urban Heat Island effect.
So is the solution to set up a
bunch of air conditioners on our streets?
Heck no.
Plant a tree instead.
Here's one more.
When it rains in Halifax, which is quite
often, that water has to go somewhere
and, if not handled properly,
it can lead to flooding and erosion.
Well, trees play an essential role in
handling that stormwater.
They slow it down with their foliage
while their roots absorb water
and stabilize the soil around them.
They're kind of like a living shamwow.
Remember those?
Anyways, trees come with a lot of benefits
and it turns out you can do the math
on how valuable they are.
With that, many smart people have
calculated that trees in Halifax
provide $9,600,000 worth of
air purifying services,
$12,400,000 worth of cooling,
and $2,100,000 in savings for
stormwater management.
In fact, it's estimated that for every
dollar we spend on a tree in Halifax,
we get $8 dollars back in benefits.
But money isn't even half the story here.
Studies have linked trees to
lowering stress, reducing crime,
reducing noise, slowing down traffic,
lowering road rage, reducing the
number of accidents, increasing
property values and, yea it's a lot.
So if there's one thing you need
to take away from all this,
it's that trees are really really
useful and important.
But if you can spare a bit more time,
I want to leave you with two more things
Size isn't always everything in life
but when it comes to trees,
it makes all the difference.
Larger trees means more air
purification, more cooling,
and more water absorption.
And it's not just that bigger trees are better,
the relationship between a tree's size
and its benefits is exponential.
That means, as a tree grows,
it's benefits grow faster?
I'm not a mathmatician but I
think all that really goes to say,
it's important to keep trees around
for their whole lives because their
benefits are greatest when they have
a chance to fully mature.
Look at this photo taken of the Halifax
Hydrostone houses just after they were
built in 1921.
Those little saplings weren't doing much
back then
but today, those trees are giving back all
kinds of benefits to this neighbourhood.
Where a tree is located is key.
As a general rule of thumb, the
closer trees are to people, the more
good they can do for people.
A really effective spot is the space
between the sidewalk and the road.
That's where a tree can provide shade
and cooling for nearby buildings while
absorbing pollutants from road traffic
and, yea, all that stuff
I mentioned earlier.
And that can be tricky.
In many cities, this part of the road is
also used for powerlines
and having trees growing near these lines
can be a hazard.
That being said, the city's position
is that it's still very much worth
the effort to plant trees here and
share the space
because the benefits are that valuable.
On top of that, they'll soon be rolling
out a program to prune street trees
regularly every seven years to
help manage those risks
and that's just great.
So to recap, trees are valuable,
bigger trees are even more valuable
and the closer trees are to us,
the more they benefit us.
Now, I have to be honest with you.
Deep down, I don't think we like trees
because of their ability to sequester
carbon, provide shade, or absorb
stormwater.
There's something more about trees
that draws us to them.
Something that's hard to put into
words or numbers.
But the thing is, a lot of the time,
that intagilble feeling we have about
trees makes it difficult to defend
keeping them.
On paper, they become a pretty thing
to look at, a nice to have, but
ultimately, a second priority.
But the reality is trees are an
essential part of our cities
and if doing a bit of math helps
us appreciate them a bit more,
well I'm all for it.
Money may not literally grow on trees,
but it most definitely pays to have
trees around.
To learn more about the role of trees
in Halifax, visit the city's urban forestry
page at their website.