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Clearing
mulga woodland in Queensland to open up land for cattle during drought. M.
Venterriven
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When
we think about adapting humanity to the challenges of climate change, it’s
tempting to reach for technological solutions. We talk about seeding our oceans and clouds with compounds designed to trigger rain or increasing
carbon uptake. We talk about building grand structures to protect our coastlines from rising sea levels and storm
surges.
However,
as we discuss in Nature Climate Change, our focus on these high-tech, heavily engineered solutions
is blinding us to a much easier, cheaper, simpler and better solution to
adaptation: look after our planet’s ecosystems, and they will look after us.
Biting
The Hand That Feeds Us
People
are currently engaged in wholesale destruction of the systems that shelter us, clean our water, clean our air,
feed us and protect us from extreme weather. Sometimes this destruction is
carried out for the purpose of protecting us from the threats posed by climate
change.
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A
seawall built using coral in Papua New Guinea J.E.M Watson
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For
example, in Melanesia’s low-lying islands, coral reefs are dynamited to provide
the raw building materials for seawalls in an attempt to slow the impact of
sea-level rise.
In
many parts of the world, including Africa, Canada and Australia, drought has
led to the opening
up of intact forest systems, protected grasslands and prairies for grazing
and agriculture.
Similarly,
the threat of climate change has driven the development of more
drought-tolerant crops that can survive climate variability, but these survival
abilities also make those plant species more likely to become
invasive.
On
the surface, these might seem like sensible ways to reduce the impacts of
climate change. But they are actually likely to contribute to climate change
and increase its impact on people.
Sea
walls and drought-tolerant crops do have a place in adapting to climate change:
if they’re sensitive to ecosystems. For example, if storm protection is
required on low-lying islands, don’t build a seawall from the coral reef that
offers the island its only current protection. Bring in the concrete and steel
needed to build it.
How
Ecosystems Protect Us
Intact
coral reefs act as barriers against storm surges, reducing wave energy by an average
of 97%. They are also a valuable source of protein that support local
livelihoods.
Similarly,
mangroves and seagrass beds provide a buffer zone against storms and reduce
wave energy, as well as being a nursery for many of the fish and other marine
creatures that our fishing industries are built on.
Intact
forests supply a host of valuable ecosystem services that are not only taken
for granted, but actively squandered when those forests are decimated
by land clearing.
There
is now clear evidence that
intact forests have a positive influence on both planetary climate and local
weather regimes. Forests also provide shelter from extreme weather events, and
are home to a host of other valuable ecosystems that are important to human
populations as sources of food, medicine and timber.
Forests
play a key role in capturing, storing and sequestering carbon
from the atmosphere, a role that will likely become increasingly important
in avoiding the worst of climate change. Yet we continue to decimate forests,
woodlands and grasslands.
Northern
Australia is home to the largest savannah on earth, containing enormous carbon
stores and influencing both local
and global climate. Despite its inherent value as a carbon store, there has
been discussion
around whether these northern regions might be opened up to become Australia’s
new food bowl, putting those extensive carbon stories in jeopardy.
Cheaper
Than Techno-Solutions
In
Vietnam, 12,000 hectares of mangroves have been planted at a cost of US$1.1
million, but saving the US$7.3 million per year that would have been spent on maintaining
dykes.
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Planting
mangroves in the Philippines to restore forests. Trees
ForTheFuture/Flickr, CC
BY
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In
Louisiana, the destruction of Hurricane Katrina in 2005 led to an examination
of how coastal salt marshes might have reduced some of the wave energy in the
hurricane-associated storm surges.
Data
have now confirmed
that salt marshes would have significantly reduced the impact of those surges,
and stabilized the shoreline against further insult, at far less cost than engineered
coastal defences. With this data in hand, discussions are now beginning
around how to restore the Louisiana salt marshes to insulate against future
extreme weather events.
US
foreign aid in Papua New Guinea has also encouraged the restoration and
protection of mangroves for the same reason.
Instead
of turning cattle to graze on native grasslands and savannah during times of
drought, farmers struggling to sustain livestock in marginal areas could
instead be funded to farm carbon and biodiversity by restoring or preserving
these ecosystems. This might involve reducing the number of cattle, or in some
cases even removing cattle entirely. Australia is very well-informed about the carbon
value of its many and varied ecosystems, but is yet to fully put that
knowledge into practice.
The
cost of adapting to climate change using largely technological solutions has
been put at a staggering US$70-100
billion per year. This is small change compared to current global energy
subsidies estimated
by the International Monetary Fund for 2015 at US$5.3 trillion per year.
Protecting
ecosystems reduces the risk to people and infrastructure, as well as the degree
of climate change: a win-win.
There is no doubt that
technological solutions have a role to play in climate adaptation but not at
the expense of intact functioning ecosystems. It is time to set a policy agenda
that actively rewards those countries, industries and entrepreneurs who develop
ecosystem-sensitive adaptation strategies.
Tara Martin, Principal
Research Scientist, CSIRO (Left); James Watson, Associate professor, The University of
Queensland (Right)
Originally published in THE CONVERSATION
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