Located at the mouth of the Bay of Bengal,

this coastal village was built on top of the Meghna River delta.

Deltas are a kind of landmass formed when sediment carried by rivers

is deposited where that river meets a larger body of water.

River deltas are incredibly fertile ecosystems

capable of supporting abundant agriculture and marine life.

However, their borders gradually change as rivers bring more sediment in

and storms wash sediment away.

The residents of Mohammadpur are well accustomed to managing

the ebbs and flows of this ever-shifting landscape.

But lately, an abundance of intense cyclones have caused frequent flooding

that impedes farming and fishing.

These floods also erode the coastline,

allowing later storms to wipe away land altogether.

Since 2000, the Meghna River has overtaken the coastline by 2.5 kilometers,

forcing many villagers to move inland or to nearby cities.

Mohammadpur isn't the only place where erratic weather is impacting people's mobility.

Repeated typhoons in the Philippines have displaced thousands from their homes.

In Fiji, the government is already moving many coastal villages inland

to get ahead of predicted land loss.

And in the United States, melting permafrost is causing chunks of the Alaskan coastline to erode.

In some ways, this is nothing new.

Humanity has always adapted to changing weather

and moved to regions that best support cultural lifestyles and livelihoods.

However, scientists agree that this rise in extreme weather

is a by-product of Earth's rapidly changing climate.

Global warming increases the frequency and intensity of storms, flooding and drought,

while also melting polar ice caps and raising sea levels.

These factors are changing the environment much faster than they have in the past.

Even for communities with the resources to take action,

the variable pace and nature of these changes makes them difficult to adapt to.

And the vulnerable populations most impacted by climate change

are often those least responsible.

Many facing climate mobility live in farming and fishing communities

in countries that generate dramatically fewer emissions than their larger counterparts.

Bangladesh is one such country.

The nation has a unique combination of low-lying geography

and heavily populated coastal regions.

Most of these vulnerable coastal families, like those in Mohammadpur,

don't want to abandon their homes and livelihoods.

And for others, leaving Bangladesh isn't financially practical.

So to stay with their communities,

many have moved a few meters inland and built more resilient homes on higher ground or elevated stilts.

Others have tried to buy land on newly emerging islands in the delta,

while some have sent family members to find work in nearby cities.

A handful of individuals might even cross international borders,

if they have family, friends, or work connections on the other side.

But many of the residents who've left are eager to return home.

Unfortunately, it's unclear when weather extremes will die down,

and the government has repeatedly delayed projects to build concrete embankments that would prevent further erosion.

In other parts of the world, people couldn't move inland even if they wanted to.

The low-lying Pacific Island nations of Kiribati and Tuvalu

are only 811 square kilometers and 26 square kilometers, respectively;

so migration would mean moving to a different country altogether.

Instead, their governments and citizens have united

in physically, legally, and politically fortifying their countries.

Island residents are planting coastal mangrove forests,

and building up low-lying areas of land with dredged sand

to shield themselves against storms and rising sea levels.

And the islands' governments have repeatedly lobbied on the global stage

for countries with the highest emissions to reduce pollution and take responsibility for climate change.

The challenges facing each coastal community are unique,

and the diversity of the people's experiences can make climate mobility a difficult phenomenon to measure and define.

But as new communities are endangered by extreme weather,

it's more important than ever to listen to those on the front lines of this crisis.