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TEDGlobal 2013

Greg Asner: Ecology from the air

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Views 698,190

What are our forests really made of? From the air, ecologist Greg Asner uses a spectrometer and high-powered lasers to map nature in meticulous kaleidoscopic 3D detail -- what he calls "a very high-tech accounting system" of carbon. In this fascinating talk, Asner gives a clear message: To save our ecosystems, we need more data, gathered in new ways.

- Airborne ecologist
Greg Asner’s mapping technology produces detailed, complex pictures of how humans’ activities affect our ecosystems. Full bio

Technology can change our understanding of nature.
00:12
Take for example the case of lions.
00:16
For centuries, it's been said that female lions
00:19
do all of the hunting out in the open savanna,
00:22
and male lions do nothing until it's time for dinner.
00:24
You've heard this too, I can tell.
00:28
Well recently, I led an airborne mapping campaign
00:31
in the Kruger National Park in South Africa.
00:34
Our colleagues put GPS tracking collars
00:36
on male and female lions,
00:39
and we mapped their hunting behavior
00:41
from the air.
00:42
The lower left shows a lion sizing up
00:44
a herd of impala for a kill,
00:46
and the right shows what I call
00:48
the lion viewshed.
00:50
That's how far the lion can see in all directions
00:52
until his or her view is obstructed by vegetation.
00:54
And what we found
00:59
is that male lions are not the lazy hunters
01:00
we thought them to be.
01:03
They just use a different strategy.
01:04
Whereas the female lions hunt
01:06
out in the open savanna
01:08
over long distances, usually during the day,
01:09
male lions use an ambush strategy
01:12
in dense vegetation, and often at night.
01:15
This video shows the actual hunting viewsheds
01:19
of male lions on the left
01:22
and females on the right.
01:23
Red and darker colors show more dense vegetation,
01:25
and the white are wide open spaces.
01:28
And this is the viewshed right literally at the eye level
01:30
of hunting male and female lions.
01:33
All of a sudden, you get a very clear understanding
01:36
of the very spooky conditions under which
01:38
male lions do their hunting.
01:41
I bring up this example to begin,
01:43
because it emphasizes how little
we know about nature.
01:44
There's been a huge amount of work done so far
01:49
to try to slow down our losses of tropical forests,
01:52
and we are losing our forests at a rapid rate,
01:55
as shown in red on the slide.
01:57
I find it ironic that we're doing so much,
01:59
yet these areas are fairly unknown to science.
02:01
So how can we save what we don't understand?
02:05
Now I'm a global ecologist and an Earth explorer
02:08
with a background in physics and chemistry
02:10
and biology and a lot of other boring subjects,
02:12
but above all, I'm obsessed with what we don't know
02:15
about our planet.
02:18
So I created this,
02:20
the Carnegie Airborne Observatory, or CAO.
02:22
It may look like a plane with a fancy paint job,
02:25
but I packed it with over 1,000 kilos
02:27
of high-tech sensors, computers,
02:30
and a very motivated staff
02:32
of Earth scientists and pilots.
02:34
Two of our instruments are very unique:
02:37
one is called an imaging spectrometer
02:39
that can actually measure the chemical composition
02:40
of plants as we fly over them.
02:42
Another one is a set of lasers,
02:45
very high-powered lasers,
02:47
that fire out of the bottom of the plane,
02:49
sweeping across the ecosystem
02:51
and measuring it at nearly 500,000 times per second
02:53
in high-resolution 3D.
02:57
Here's an image of the Golden Gate Bridge
02:59
in San Francisco, not far from where I live.
03:01
Although we flew straight over this bridge,
03:04
we imaged it in 3D, captured its color
03:05
in just a few seconds.
03:07
But the real power of the CAO
03:09
is its ability to capture the actual building blocks
03:11
of ecosystems.
03:13
This is a small town in the Amazon,
03:15
imaged with the CAO.
03:17
We can slice through our data
03:18
and see, for example, the 3D structure
03:20
of the vegetation and the buildings,
03:22
or we can use the chemical information
03:25
to actually figure out how fast the plants are growing
03:27
as we fly over them.
03:29
The hottest pinks are the fastest-growing plants.
03:31
And we can see biodiversity in ways
03:34
that you never could have imagined.
03:36
This is what a rainforest might look like
03:38
as you fly over it in a hot air balloon.
03:40
This is how we see a rainforest,
03:42
in kaleidoscopic color that tells us
03:44
that there are many species living with one another.
03:46
But you have to remember that these trees
03:49
are literally bigger than whales,
03:51
and what that means is that
they're impossible to understand
03:54
just by walking on the ground below them.
03:57
So our imagery is 3D, it's chemical, it's biological,
03:59
and this tells us not only the species
04:04
that are living in the canopy,
04:06
but it tells us a lot of information
04:08
about the rest of the species
that occupy the rainforest.
04:10
Now I created the CAO
04:13
in order to answer questions that have proven
04:15
extremely challenging to answer
from any other vantage point,
04:18
such as from the ground, or from satellite sensors.
04:21
I want to share three of those
questions with you today.
04:24
The first questions is,
04:27
how do we manage our carbon reserves
04:29
in tropical forests?
04:30
Tropical forests contain a huge
amount of carbon in the trees,
04:33
and we need to keep that carbon in those forests
04:37
if we're going to avoid any further global warming.
04:39
Unfortunately, global carbon emissions
04:43
from deforestation
04:45
now equals the global transportation sector.
04:47
That's all ships, airplanes, trains
and automobiles combined.
04:50
So it's understandable that policy negotiators
04:54
have been working hard to reduce deforestation,
04:57
but they're doing it on landscapes
05:00
that are hardly known to science.
05:01
If you don't know where the carbon is exactly,
05:04
in detail, how can you know what you're losing?
05:06
Basically, we need a high-tech accounting system.
05:09
With our system, we're able to see the carbon stocks
05:13
of tropical forests in utter detail.
05:15
The red shows, obviously,
closed-canopy tropical forest,
05:18
and then you see the cookie cutting,
05:21
or the cutting of the forest in yellows and greens.
05:23
It's like cutting a cake except this cake
05:27
is about whale deep.
05:30
And yet, we can zoom in and see the forest
05:32
and the trees at the same time.
05:34
And what's amazing is, even though we flew
05:36
very high above this forest,
05:38
later on in analysis, we can go in
05:40
and actually experience the treetrops,
05:42
leaf by leaf, branch by branch,
05:44
just as the other species that live in this forest
05:47
experience it along with the trees themselves.
05:50
We've been using the technology to explore
05:53
and to actually put out the first carbon geographies
05:55
in high resolution
05:58
in faraway places like the Amazon Basin
06:00
and not-so-faraway places like the United States
06:02
and Central America.
06:04
What I'm going to do is I'm going to take you
on a high-resolution, first-time tour
06:06
of the carbon landscapes of Peru and then Panama.
06:09
The colors are going to be going from red to blue.
06:13
Red is extremely high carbon stocks,
06:16
your largest cathedral forests you can imagine,
06:18
and blue are very low carbon stocks.
06:21
And let me tell you, Peru alone is an amazing place,
06:23
totally unknown in terms of its carbon geography
06:25
until today.
06:28
We can fly to this area in northern Peru
06:29
and see super high carbon stocks in red,
06:31
and the Amazon River and floodplain
06:33
cutting right through it.
06:35
We can go to an area of utter devastation
06:37
caused by deforestation in blue,
06:38
and the virus of deforestation
spreading out in orange.
06:40
We can also fly to the southern Andes
06:44
to see the tree line and see exactly how
06:46
the carbon geography ends
06:48
as we go up into the mountain system.
06:50
And we can go to the biggest swamp
in the western Amazon.
06:53
It's a watery dreamworld
06:56
akin to Jim Cameron's "Avatar."
06:57
We can go to one of the smallest tropical countries,
07:00
Panama, and see also a huge range
07:03
of carbon variation,
07:05
from high in red to low in blue.
07:07
Unfortunately, most of the carbon
is lost in the lowlands,
07:09
but what you see that's left,
07:12
in terms of high carbon stocks in greens and reds,
07:13
is the stuff that's up in the mountains.
07:16
One interesting exception to this
07:18
is right in the middle of your screen.
07:20
You're seeing the buffer zone
around the Panama Canal.
07:22
That's in the reds and yellows.
07:25
The canal authorities are using force
07:27
to protect their watershed and global commerce.
07:28
This kind of carbon mapping
07:31
has transformed conservation
07:33
and resource policy development.
07:35
It's really advancing our ability to save forests
07:36
and to curb climate change.
07:39
My second question: How do we
prepare for climate change
07:41
in a place like the Amazon rainforest?
07:45
Let me tell you, I spend a lot of time
07:47
in these places, and we're seeing
the climate changing already.
07:48
Temperatures are increasing,
07:52
and what's really happening is
we're getting a lot of droughts,
07:53
recurring droughts.
07:56
The 2010 mega-drought is shown here
07:58
with red showing an area
about the size of Western Europe.
07:59
The Amazon was so dry in 2010
08:03
that even the main stem of the Amazon river itself
08:05
dried up partially, as you see in the photo
08:08
in the lower portion of the slide.
08:10
What we found is that in very remote areas,
08:13
these droughts are having a big negative impact
08:16
on tropical forests.
08:19
For example, these are all of the dead trees in red
08:21
that suffered mortality following the 2010 drought.
08:23
This area happens to be on the border
08:26
of Peru and Brazil,
08:28
totally unexplored,
08:30
almost totally unknown scientifically.
08:31
So what we think, as Earth scientists,
08:34
is species are going to have to migrate
08:36
with climate change from the east in Brazil
08:38
all the way west into the Andes
08:41
and up into the mountains
08:43
in order to minimize their
exposure to climate change.
08:45
One of the problems with this is that humans
08:48
are taking apart the western Amazon as we speak.
08:50
Look at this 100-square-kilometer gash
08:53
in the forest created by gold miners.
08:55
You see the forest in green in 3D,
08:58
and you see the effects of gold mining
09:01
down below the soil surface.
09:02
Species have nowhere to migrate
in a system like this, obviously.
09:05
If you haven't been to the Amazon, you should go.
09:09
It's an amazing experience every time,
09:12
no matter where you go.
09:14
You're going to probably see it this way, on a river.
09:16
But what happens is a lot of times
09:19
the rivers hide what's really going on
09:21
back in the forest itself.
09:23
We flew over this same river,
09:25
imaged the system in 3D.
09:27
The forest is on the left.
09:29
And then we can digitally remove the forest
09:31
and see what's going on below the canopy.
09:33
And in this case, we found gold mining activity,
09:35
all of it illegal,
09:38
set back away from the river's edge,
09:39
as you'll see in those strange pockmarks
09:41
coming up on your screen on the right.
09:43
Don't worry, we're working with the authorities
09:45
to deal with this and many, many other problems
09:47
in the region.
09:50
So in order to put together a conservation plan
09:52
for these unique, important corridors
09:55
like the western Amazon
and the Andes Amazon corridor,
09:57
we have to start making
10:00
geographically explicit plans now.
10:02
How do we do that if we don't know
the geography of biodiversity in the region,
10:05
if it's so unknown to science?
10:09
So what we've been doing is using
10:10
the laser-guided spectroscopy from the CAO
10:12
to map for the first time the biodiversity
10:15
of the Amazon rainforest.
10:18
Here you see actual data showing
different species in different colors.
10:19
Reds are one type of species, blues are another,
10:23
and greens are yet another.
10:25
And when we take this together and scale up
10:27
to the regional level,
10:29
we get a completely new geography
10:31
of biodiversity unknown prior to this work.
10:34
This tells us where the big biodiversity changes
10:38
occur from habitat to habitat,
10:40
and that's really important because it tells us
10:42
a lot about where species may migrate to
10:44
and migrate from as the climate shifts.
10:47
And this is the pivotal information that's needed
10:50
by decision makers to develop protected areas
10:53
in the context of their regional development plans.
10:57
And third and final question is,
11:00
how do we manage biodiversity on a planet
11:02
of protected ecosystems?
11:04
The example I started out
with about lions hunting,
11:06
that was a study we did
11:09
behind the fence line of a protected area
11:11
in South Africa.
11:13
And the truth is, much of Africa's nature
11:15
is going to persist into the future
11:17
in protected areas like I show in blue on the screen.
11:19
This puts incredible pressure and responsibility
11:22
on park management.
11:24
They need to do and make decisions
11:26
that will benefit all of the species
that they're protecting.
11:29
Some of their decisions have really big impacts.
11:32
For example, how much and where
11:35
to use fire as a management tool?
11:37
Or, how to deal with a large species like elephants,
11:40
which may, if their populations get too large,
11:43
have a negative impact on the ecosystem
11:45
and on other species.
11:47
And let me tell you, these types of dynamics
11:49
really play out on the landscape.
11:51
In the foreground is an area with lots of fire
11:53
and lots of elephants:
11:56
wide open savanna in blue, and just a few trees.
11:57
As we cross this fence line, now we're getting
12:01
into an area that has had protection from fire
12:03
and zero elephants:
12:05
dense vegetation, a radically different ecosystem.
12:07
And in a place like Kruger,
12:11
the soaring elephant densities
12:14
are a real problem.
12:15
I know it's a sensitive issue for many of you,
12:17
and there are no easy answers with this.
12:20
But what's good is that
the technology we've developed
12:22
and we're working with in South Africa, for example,
12:25
is allowing us to map every
single tree in the savanna,
12:27
and then through repeat flights
12:30
we're able to see which trees
12:32
are being pushed over by elephants,
12:34
in the red as you see on the screen,
and how much that's happening
12:36
in different types of landscapes in the savanna.
12:39
That's giving park managers
12:42
a very first opportunity to use
12:43
tactical management strategies
that are more nuanced
12:46
and don't lead to those extremes
that I just showed you.
12:49
So really, the way we're looking
12:54
at protected areas nowadays
12:56
is to think of it as tending to a circle of life,
12:58
where we have fire management,
13:01
elephant management, those impacts on
the structure of the ecosystem,
13:03
and then those impacts
13:08
affecting everything from insects
13:10
up to apex predators like lions.
13:12
Going forward, I plan to greatly expand
13:15
the airborne observatory.
13:16
I'm hoping to actually put the technology into orbit
13:18
so we can manage the entire planet
13:20
with technologies like this.
13:22
Until then, you're going to find me flying
13:24
in some remote place that you've never heard of.
13:26
I just want to end by saying that technology is
13:28
absolutely critical to managing our planet,
13:31
but even more important is the understanding
13:34
and wisdom to apply it.
13:36
Thank you.
13:38
(Applause)
13:40

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About the speaker:

Greg Asner - Airborne ecologist
Greg Asner’s mapping technology produces detailed, complex pictures of how humans’ activities affect our ecosystems.

Why you should listen

The remote sensing techniques developed by Greg Asner and his team are viewed as among the most advanced in the world for exploring Earth’s changing ecosystems in unprecedented detail and richness. Using airborne and satellite technologies such as laser scanning and hyperspectral imaging, combined with field work and computer modeling, Asner measures and qualifies humans’ impact on regions from the American Southwest to the Brazilian Amazon.

“We’re able to see, if you will, the forest and the trees at the same time,” Asner says. “We’re able to now understand an image, map and measure huge expanses of the environment while maintaining the detail. Not just the spatial resolution, but the biological resolution—the actual organisms that live in these places.” For Asner, who is on the faculty at the Carnegie Institution and Stanford and leads the Carnegie Airborne Observatory project, this is science with a mission: to influence climate change treaties and save the forests he studies.

More profile about the speaker
Greg Asner | Speaker | TED.com