Translator: lisa thompson Reviewer: Peter van de Ven
By show of hands, how many of you believe this statement to be true?
(Murmuring)
One taker.
Don't be silly.
Grass cannot dream.
(Laughter)
But I'm kidding.
It's not far off.
But what I want you to do is just keep this concept in your head
as we go through this presentation.
Coffee is the world's most valuable tropical export crop.
There are 25 million smallholders worldwide
and around 100 million people that rely on coffee directly for their livelihoods -
so an incredibly important crop for smallholder farmers.
If we look at this in sense of a country,
take Tanzania, for example,
coffee generates an income
in the order of around USD$100 million per year for the country.
So incredibly important for the tropics
and for all the tropical countries which grow it:
Ethiopia, Tanzania, Uganda, Burundi, Rwanda -
and then into South America - Columbia, Costa Rica.
This is a picture of where coffee originated -
so this we took in southwestern Ethiopia -
although it is now heavily contested
as it may actually have originated in the southern Sudanese highlands.
But somewhere around there, coffee originated as an understory crop -
so grown within the shade of other beautiful, big, indigenous vegetation -
and thrives within a tiny bracket of between 18°C and 21°C.
Of course, it needs ample amount of rainfall and at the correct times.
But if the temperatures move above or below 18°C and 21°C,
the plant starts to physiologically not perform correctly,
and ultimately affects the impact of either the quality or the production.
So it has an incredibly tiny, small bracket
within which coffee is happy to grow.
This is coffee -
happy little coffee cherries growing in a plant within the Tanzanian highlands -
Ngorongoro Crater on the background there -
without any shade.
So a couple decades ago, we realized,
hey, we're able to cut out all the shade,
maximize production and yields, and get a lot more coffee out there.
Two problems came with this:
The one in that you need a lot of input to be able to do this;
you need a lot of irrigation, a lot of fertilizer,
a lot of herbicides, a lot of pesticides.
And two, if you do run into trouble with any sort of climate,
you're not going to be protected by any nice trees around you.
So we fell into two big problems.
Governments maximized this, cut a lot of trees out,
and had coffee growing in full sun.
Big problem - climate change.
So temperature is increasing.
These are graphs from where we did the majority of our research, in Tanzania.
So you can see, from 1960-2010, the increases in all three temperatures.
What does that mean for coffee exposed?
A big problem.
So we find problems of coffee throughout the world.
In the top left, coffee wilting from stress,
unequal ripening next to that,
and below, a lot of pest and disease pressure,
where coffee berries just die.
So what did we do about it?
We looked into it.
We're looking for adaptation strategies for the plant and for farmers.
When we dug a little deeper,
we had a look at these different temperature trends,
and we knew, in current or previous coffee research thinking,
that maximum temperatures throughout the day are far too hot,
and like any other plant,
he's giving up and really stressing and struggling to cope with it.
When we looked into this, it actually wasn't the case.
We did a whole bunch of tests.
We analyzed this in very different ways.
And we found a very little, sneaky problem with the minimum temperatures.
So, as you can see over here,
the minimum temperatures are increasing at a much faster rate
than your maximums to the right of that.
These particular minimum temperatures are increasing at 0.31° per decade
whereas the maximums are at about 0.23° per decade.
And if you look at this globally,
you find this phenomenon in almost every single country,
or at least the tropical growing countries,
so Ethiopia; Costa Rica; Colombia; Brazil, a massive producer.
All these increasing nighttime temperatures
are slowly creeping up on us,
and when we ran this through everything,
we really found that they are actually the culprit impacting coffee.
If you look at this in one graph,
starting between 14°C, running up to 18°C,
Tanzania's average coffee production for a smallholder farmer
was around 500 kilos per hectare.
This was back in 1960.
Today, it's about half of that, at about 200 kilos per hectare.
And if we project this forward, as you can see on this nice line,
it drops to close to nothing.
And we're pretty much in the middle there,
where you see that last dot moving from left to right.
And so we're really losing at a massive rate,
all related to your nighttime or your minimum temperatures.
If we project this into the future, so you have a look there -
all the little shaded regions are your major coffee-producing areas.
And you can see in the northwestern sector,
south, southeastern sector, all the massive increases in temperature.
This is a projection to 2050.
All the dark areas are an increase of between 1.3°C and 1.5°C.
So that change in temperature is absolutely huge for coffee.
If we look at what this means for yields,
you can see we stop where the black line stops,
and current or future projection starts where your blue line is,
and you can see, it drops quite a bit below that.
Why do we think this is so,
and why is it the nighttime, and why is it the minimums?
We're still working on it, but a good guess is -
if you look at this, this is a smallholder plantation,
a typical smallholder plantation in Africa.
They grow like this throughout the world.
You'll have your old coffee tree.
You'll have some cocoyams or some beans below that.
You'll have a nice, multistratified layer of shade above that;
you'll have your bananas or shade trees, your fruit trees.
It's fantastic for a smallholder farmer;
he can harvest all different crops at times of the year.
Also, it keeps the hot daytime sun's heat off of the coffee
and cools it down by at least 4°C.
The problem with this, which is why we think this is happening,
is that nice dense canopy layer of vegetation is acting like a greenhouse,
so at night, when all your heat from the ground and terrestrial radiation
is meant to be escaping back into space,
it's getting trapped by all this vegetation
and causing a nice little greenhouse effect for the coffee.
So we're a little bit stuck.
On one hand, we need shade for the daytime;
on the other hand, we want it to go away
so at night it can escape back out.
What do we do?
So, I take you back to the thought of the dreaming grass,
plants are actually incredible, incredible, incredible biotic species.
So, we always think of animals as able to adapt,
humans as able to adapt;
plants are the most incredible adaptive species on Earth.
They have senses.
We have gone so far now into neurobiology
to believe that plants are actually intelligent;
they're able to learn from stuff that they've done before
and adapt to that.
And this is how we're working with plants -
with that in mind -
to try and get adaptation strategies which support the plant in the future.
So we use a whole bunch of very cool little techniques
where, if you think of us humans,
if we're being attacked by a bacteria or a virus,
we heat up; we get a temperature.
Plants do the exact same thing.
So if they're unhappy, they will heat up.
We used a very nice, sensitive camera to look at different leaves
and different plants and different shading environments
at different altitudes - all over East Africa -
and we have a look where coffee is happy and where it's not happy,
and hopefully we'll find out a good, suitable environment
in which it can thrive and increase the odds of productivity.
Elephants in Ngorongoro Crater -
so, these guys move throughout the forest,
and then they come into the coffee, and they start eating cherries.
There's a guy that moves around.
And I don't know if you've heard the story of kopi luwak,
where it's an Indonesian civut, a cat, that eats the coffee cherries.
It then gets predigested.
People then collect it and make coffee out of it.
There's a guy roaming around who does the same thing with elephants:
digs through elephant dung, collects the cherries,
roasts them, and then sells it to people.
If you ever see this guy around, do not buy coffee -
he's been sifting through it.
And especially at functions, events, that type of thing -
could be drinking elephant dung.
(Laughter)
Thank you.
(Applause)