Mangroves, Storm Walls and Other Ways to Protect Coasts from Climate Change | Dave Sivaprasad | TED

So 40 percent of the world’s population live near the coast.

So you’ve got sea level rise, intense storms

and, by some estimates,

half a billion to a billion people will be adversely affected

by what's going to happen in the coast.

But that's not the only problem.

It's a bit more complicated than that.

It's not just storms are increasing,

sea level rise is going to flood these areas.

You have secondary issues,

such as acidification that's going to damage coral reefs

and natural systems.

You have changing wind patterns because ocean temperatures are increasing

and storms are getting more intense and also more unpredictable.

And on top of that, you've got increased rainfall

and flooding that is happening deeper in the coast

in coastal communities.

This is a big problem.

And it's a personal problem for me as well.

I'm from Singapore, an island state in Southeast Asia.

Many coastal communities.

I worry about what's going to happen to my region,

how it's going to impact my family.

I've got three boys that, you know, have grown up along the coast.

And with that, I've spent the last two years

helping countries and coastal communities build resilience against climate change.

What's the challenge?

The challenge is no two coasts are alike.

They are highly diverse, physically diverse.

They have different distributions of populations.

And they are socioeconomically different

in terms of the communities that live there.

Now, there are many solutions to protect the coast.

You have seawalls, storm barriers.

We can restore mangroves.

And this can protect the coast.

The challenge is not so much the solutions.

The challenge is actually what's the right mix of solutions

that fits the local context

and delivers the highest socioeconomic return.

Now, let me illustrate this with an example.

I worked with a government in Southeast Asia,

a country with a large population, diverse set of islands,

many coastal communities, spread across.

And one region in particular faced a complex interplay of challenges.

Rising sea levels that were causing permanent flooding.

Increasing storms that were damaging the coast.

A large proportion of vulnerable people, in poverty, living in low-lying areas.

On top of that, land subsidence had made matters worse.

So we worked with the government to model the impact of climate change

over the coming decades

to answer questions like:

Which parts of the coast will be flooded?

Which populations will be impacted?

Where would schools, hospitals, critical infrastructure be damaged?

How would this impact crops, water systems?

What would be the impact on natural ecosystems

that are important to this country.

And importantly, what this did was that it combined climate science

with data analytics,

with local context,

and linked it to socioeconomic impact.

Now, to give an example, one particular community faced the risk

of 100,000 people potentially being displaced

because of increasing sea levels.

Eight percent of the economy

and almost half of the region's wetland reserves

were at risk of being damaged.

Now, in addition, with this insight

the government was able to better understand the knock-on effects

that this would have on public health, on food security,

on forced migration.

So a lot of issues.

So what do you do about that?

I mean, this massive exposure and no clear answers in what you do,

and in a developing economy such as this,

massive trade-offs that you need to manage in terms of where you deploy resources.

So ...

Initially this region was looking at building seawalls,

having early warning systems, storm barriers in place

that required a fair bit of capital and investment.

In fact, what we found was that a mix of solutions were needed.

So that included mangrove restoration in selected areas as natural defense

and only in certain parts of the coast

investing to build storm barriers and seawalls.

Now with that, the region could consider --

with the same amount of resources, maximizing lives saved,

livelihoods protected and ecosystem safeguarded.

And on top of this, the cost of inaction, of not doing anything,

also meant massive negative impact for the private sector.

So private enterprises would have had billions of dollars of losses

with manufacturing, with critical infrastructure,

with commercial real estate being damaged.

Now, having a visibility on this,

the government could then engage the private sector

on codeveloping and cofunding solutions

that benefitted both private enterprise

and the local community.

Now, this is not a problem only in Southeast Asia.

A city in West Africa, for example, had similar challenges

but compounded with very dense populations along the coast,

severe land subsidence

and drainage challenges

that were exacerbated by poor solid waste management

in some parts of the city.

Now by integrating climate science data analytics to local context

and tightly linking this to socioeconomic impact,

the government was able to manage the trade-offs

on how you would balance the deployment of resources

to things such as:

Do I build more drainage infrastructure?

Do I relocate some populations to other parts?

Do I build storm barriers?

What's the right mix?

Now as you can see, this is a challenging and complex problem.

And when you look at it,

the challenge is every coast that you look at is different.

Right? They're socioeconomically, physically different.

And the most pressing challenges are often in developing countries

where they have limited capacity to adapt

and they have big trade-offs to manage.

On top of this, there are many technical solutions

and natural solutions out there.

You can protect the coast with mangrove restoration,

seawalls, storm barriers.

You can accommodate by flood-proofing buildings,

building drainage.

You can relocate people and critical infrastructure.

The challenge is not so much what are these solutions,

rather what's the right mix of solutions for any given context.

So by combining climate science, data analytics,

to local considerations, tightly to socioeconomic outcomes,

decision makers can really balance the trade-offs

and take the right actions over time

to be able to maximize lives saved,

livelihoods protected and natural ecosystems saved.

So with that ...

we could protect more people along the coast

and optimize the outcomes.

Thank you.

(Applause)