A tree goes up in flames as a wildfire burns on the Northern Cheyenne Indian Reservation, Wednesday, Aug 11, 2021, near Lame Deer, Mont. The Richard Spring fire was threatening hundreds of homes as it burned across the reservation. Matthew Brown, Associated Press

So far this year, wildfires have displaced tens of thousands of people in the U.S., Canada, Greece and Turkey. Monsoons have displaced thousands in the U.S., India and Bangladesh. And massive floods have displaced over a million more in Germany, China and Myanmar.

During just one week this summer, at least 40 countries experienced extreme weather events, reported Down To Earth. Countries in Africa, Asia, Europe, North America and Oceania were all affected. The photos and videos from these disasters have looked like horror movies filled with apocalyptic scenes.

Right now — through shaky videos shot on the phones of fleeing victims — we’re watching a movie trailer for a much larger trend just around the corner: climate migration.

Just like the natural disasters that contribute to this trend, there are natural and disastrous components to climate migration. And just like the complexities surrounding natural disasters, many complexities surround climate migration.

There’s a lot we still don’t know about climate migration, but we do know that this migration is coming — fast — and it could become the largest migration of people in human history, according to The New York Times.

So let’s unpack this topic — because sooner than you think, your phone could be filming a disaster and you could be the next climate migrant.

The landscape of climate migration

Climate migrants — sometimes called climate refugees or environmental migrants — come in many forms, from many places, for many reasons, according to the United Nation’s International Organization for Migration.

“Whether it’s a large one-time event, or it’s a cumulative of events from hurricanes and flooding and wildfires or if it’s a chronic condition,” said Sabina Shaikh, director of the University of Chicago’s Program on Global Environment, per WTTW News.

“Broadly speaking ... climate refugees are people who are displaced by climate events,” Shaikh said.

Climate migrants may be displaced internally or internationally, temporarily or permanently, close to their homes or far from their homes. Their displacement may be forced or voluntary, planned or unplanned, collective or individual. The cause of their displacement could be sudden or slow, according to the U.N. International Organization for Migration.

Essentially, climate migration varies widely.

A San Francisco ‘tech bro’ choosing to move out of the wildfire smoke to a growing tech hub in Texas? Arguably a climate migrant.

A Guatemalan family moving to the capital city to find jobs after repeated crop failures? Climate migrants.

A Dutch community planning to leave the Netherlands due to slowly rising sea levels? Also climate migrants.

All of these people — while geographically, socioeconomically and ethnically diverse — demonstrate how various climate processes can lead to the same outcome: migration.

The process of climate migration

Generally, people migrate due to two types of climate events: sudden onset events and slow onset events, per the U.N. International Organization for Migration.

Sudden onset events are the simplest to explain. These events are often considered natural disasters — wildfires, floods, tropical storms and the like. Often, these events are dramatic and eye-catching.

And these extreme weather events are getting more frequent and more intense due to climate change, according to the latest and most comprehensive study from the U.N.’s Intergovernmental Panel on Climate Change.

Slow onset events are more complex to explain but equally concerning.

To provide an example commonly seen by researchers, consider a rural community where the environment hasn’t been normal recently. Droughts have worsened over the last few years, making water far too scarce and heat far too plentiful. Fires spark easily and spread quickly. Crop failures are happening more and more frequently as the land degrades.

Hunger and food scarcity loom. Competition for dwindling natural resources has begun to fuel violent conflict, reported Pass Blue, an international news agency.

“Many will dig in, suffering through heat, hunger and political chaos, but others will be forced to move on,” said Abrahm Lustgarten, an environmental reporter for ProPublica, in The New York Times.

Most of those forced to move on from rural areas won’t pack up for an international destination. Rather, they will likely follow a pattern of “stepwise” migration, Lustgarten said. First, people will leave their current rural home for a larger city nearby. Then, if conditions in the city aren’t better, they will consider crossing borders on longer, riskier journeys.

Regardless of where and when and why people begin migrating, research has repeatedly found that climate migrants will gravitate toward cities and drive urbanization, according to a recent study by One Earth.

And in cities, the natural side of climate migration collides with the disastrous side.

A team of Northwest Fire District firefighters walk a woman away from a stranded pickup truck in the Cañada del Oro Wash north of Tucson, Ariz., on Tuesday, Aug. 10, 2021. Firefighters rescued three people from one of two vehicles in the wash, swollen with runoff after an early morning downpour dumped nearly 2-inches upstream. Rick Wiley, Arizona Daily Star via Associated Press

The natural side of climate migration

Wildfires, monsoons and floods aren’t inherently disasters. Rather, each plays an important role in the natural cycle of ecosystems, reported National Geographic.

Human migration is similar. Fundamentally, the story of people moving around the world is nothing new, as one U.N. commenter noted.

“Migration can bring great opportunity not just to migrants but also to the places they go,” Lustgarten wrote for The New York Times.

Domestic migrants can benefit from the employment, education and health care offered in cities, reported the U.N. Conversely, cities can benefit from the expanded workforce to boost economic output.

Similarly, international migrants of all skill levels benefit their new countries economically over the long term, according to studies from the International Monetary Fund.

“Because of this complexity and multicausality, environmental migration should not be understood as a wholly negative or positive outcome,” said the U.N. International Organization for Migration.

But while migration can afford people better opportunities, it “can also amplify existing vulnerabilities,” the organization said.

The disastrous side of climate migration

Climate changes driving migration can compound the severity of many pre-existing issues and threaten to create a disastrous cycle.

For example, climate migrants will flock to urban areas, likely increasing populations in flood-prone areas— a preexisting environmental issue.

This will further burden the already strained resources and infrastructures of cities — a preexisting developmental issue.

Simultaneously, the influx will likely increase unemployment and housing shortages — preexisting economic issues — leading to the expansion of slums — a preexisting social issue.

Combined, the rapid and chaotic urbanization can exacerbate preexisting political issues — potentially enough to topple states and cause violent conflict.

And in a cyclic fashion, this will further drive migration for all sorts of reasons.

“Climate is rarely the main cause of migration, the studies have generally found, but it is almost always an exacerbating one,” said Lustgarten in The New York Times, noting that on a global scale, anywhere from 50 million to 300 million people will be displaced due to sudden onset or slow onset climatic conditions by 2050.

Other researchers have given even higher estimates.

In 2018, The Institute for Economics and Peace predicted that at least 1.2 billion people could be displaced by climate-related events by 2050, reported The World Economic Forum.

Based on those estimations, the wave of climate migrants could range in size from the entire population of Colombia to the entire population of the African continent, per Worldometer data.

But these data estimates are exactly that — estimates. The exact number of migrants, their migration timeline, and their migration routes all remain uncertain, according to The World Economic Forum.

Still, we can be sure of this much: It “will be the greatest wave of global migration the world has seen,” Lustgarten said.

And the next migrant could be you

About 1.71 million people in the U.S. were displaced by disasters in 2020 alone, according to the Internal Displacement Monitoring Centre. And that number is only expected to rise in coming years.

By some estimates, tens of millions of Americans may become climate migrants in the coming years, The New York Times reported. Many American climate migrants will be pushed to move due to hotter temperatures, drier lands and rising sea levels.

There will be no historical precedent — in the U.S. or in the world — for the flow of people expected in climate migration, according to a data analysis by Harvard.

So can we avoid a crisis?

The disastrous side of climate migration is not guaranteed, but neither is the natural side, according to the U.N. International Organization for Migration. So we’re left at a crossroads.

“The best outcome requires not only goodwill and the careful management of turbulent political forces; without preparation and planning, the sweeping scale of change could prove wildly destabilizing,” Lustgarten wrote for The New York Times.

To even begin planning for the greatest migration in history, we will need data — and lots of it — to understand the mosaic of movement. Standardized and shared data on internal and international displacements, on the timelines of migrants affected by slow onset process, and on trapped populations who would be climate migrants but lack resources, per the Migration Data Portal.

And when the politically charged debates inevitably rage, we must remember that “nobody wants to migrate away from home, even when an inexorable danger is inching ever closer,” Lustgarten said. “They do it when there is no longer any other choice.”