The author, best known for his No.1 Ladies Detective Agency books joined forced with environmental charity to mark this years Earth Hour,
His poem is to help encourage people to join in the Great Scottish Canvas project, which the charity is launching.
WWF hope that during Earth Hour on Saturday, March 27 at 8.30pm, people across the country will use their time to paint a picture, craft a poem, doodle or write something about the future Scotland they want to live in.
A selection of entries will appear in a virtual exhibition later this year.
Launching the Great Scottish Canvas, Alexander McCall Smith said: “I am delighted that so many people are joining together to celebrate this key moment for the world.
"The words and images that this project gathers all have one thing in common - they recognise that this is simply the most important issue that humanity faces.”
Lang Banks, director at WWF Scotland added: “We’re thrilled Alexander McCall Smith has shared this moving, new poem, which we are sure will inspire others to contribute something of their own to our Great Scottish Canvas.
"We hope people will take inspiration for their own creative poems, drawings and artworks about Scotland’s nature and its future, and the actions they want to see happen to protect our one shared home.”
The new poem, written exclusively for WWF Scotland’s Great Scottish Canvas, is titled Only One Home, and will feature in a virtual exhibition of selected entries from the public.
Alexander McCall Smith poem ‘Only One Home’
It's always useful, we're told,
To ensure a spare is ready to hand:
About the house an extra pair
Of spectacles may come in useful,
A front door key, or two perhaps,
Concealed for emergency use;
These things are simply prudent, signs
Of a cautious mentality, of planning ahead
For the unexpected, the contingency
We never thought would come about;
And yet there are some important things,
Of which we may possess only one:
Each of us has only one heart, one life,
One memory in which to lodge the remembrance
Of the things we know and love;
These are private and individual limitations;
Singularity applies, though, just as much
To that which belong to all:
We have only one home, one planet,
One earth on which each of us may sit down
And speak of and treat as our own:
Only one, irreplaceable, unduplicated
By a spare earth somewhere else;
Just this one, this one we love.
And that, perhaps, is what we might
Tell ourselves as we look upon it
With a lover's eyes, this precious place,
Source of all meaning to us,
Site of all that we've ever known.
Ever felt, or ever dreamed about,
This spinning place, green and blue.
Shrouded at times by cloud, made golden
By sunsets that make us want to cry;
This is the only one we have;
This is the one that we must cherish,
Distinctive in the light of our individual moods
And different ways of looking at things,
Yet equally dear, equally nourishing,
Equally in need of our stewardship
Now, as never before; our only home.