05/05/2017 03:59 EDT | Updated 05/05/2017 04:16 EDT

Rising Tides Will Create The World's Next Refugee Crisis

As human-caused climate change continues to warm the planet, sea levels will rise, storms will grow stronger, floods more violent and draughts harsher. All of this puts some of the world's most vulnerable people at greater risk.

By Craig and Marc Kielburger

As the Brooklyn streets went dark and flooded with water, pummeled by the onslaught of Hurricane Sandy, Lizbeth Lucero watched her mother pace the apartment -- and pray.

In the weeks that followed, her family went without power or heat. Another 760,000 were forced from their homes.

A flooded Brooklyn Battery park Tunnel Oct. 30, 2012 as New Yorkers clean up the morning after Hurricane Sandy's landfall. (Photo: Timothy A. Clary/AFP/Getty Images)

Churches provided blankets for cold nights while Lizbeth's family ate hot dogs and Salvadorian pupusas donated by food trucks. Still without power at home, she returned to school and a teacher offered her a warm shower in the school's basement.

Lizbeth turned it down, ashamed at needing help.

We were reminded of Lizbeth's story, and of those displaced from their homes or forced to flee their country as climate refugees, this Earth Day.

Mass displacements will soon be the new normal.

Hundreds of thousands of scientists and environmental advocates filled the streets in over 600 cities, with rallies taking place on every continent -- even Antarctica. Bill Nye told thousands gathered in the pouring rain in Washington, D.C., "We are marching today to remind people everywhere of the significance of science."

The earth needs protection -- that was a central theme of the rallies -- but so do its people. Experts say climate change poses the greatest security threat and mass displacements will soon be the new normal.

Demonstrators march to the U.S. Capitol during the March for Science in Washington, D.C., April 22, 2017. (Photo: Aaron P. Bernstein/Reuters)

As human-caused climate change continues to warm the planet, sea levels will rise, storms will grow stronger, floods more violent and draughts harsher. All of this puts some of the world's most vulnerable people at greater risk.

They are the human face of global warming.

On Earth Day, amid calls to reign in carbon emissions, end deforestation and protect coral reefs, we heard another conversation. Awareness was raised for Tuvalu, the Polynesian island at risk of disappearing into bloated waters, and action demanded for the 200,000 Bangladeshis who lose their homes each year from river erosion.

A young man wades through floodwaters as Funafuti, Tuvalu is inundated during one of the highest tides. (Photo: Ashley Cooper/Corbis via Getty Images)

The problem is complex, as are the solutions. But as with most climate issues, prevention is best. Reforestation, re-habilitating degraded land, and desalination of low coastal areas will ensure that at-risk communities are more resilient to change.

Once disaster strikes, another necessary step is legal recognition for the people fleeing devastation brought on by climate change.

The United Nations Refugee Convention only extends to members of persecuted groups. People driven from their homes by rising ocean tides or creeping deserts don't qualify for legal protection, which means many country's doors remain closed and safe asylum is out of reach. Some estimates say climate refugees and internally displaced people will number 50 million by 2020 and 150 million by 2050.

Bill Nye speaks during a press conference before a global climate march outside New York City Hall on Nov. 29, 2015. (Photo: Kena Betancur/Getty Images)

After Hurricane Sandy, Lizbeth poured herself into climate action. She marshalled her community to join the 300,000 strong People's Climate March in Manhattan in 2014. And she became a leader in the Red Hook Initiative to help build a resilient and healthy community.

The helplessness she felt during the hurricane was Lizbeth's spark. It was part of what drove her to become the first person in her family of Mexican immigrants to graduate high school.

Now studying development sociology at Cornell, she carries that spark with her, a glimmer of hope that vulnerable people will not be forgotten.

Craig and Marc Kielburger are the co-founders of the WE movement, which includes WE Charity, ME to WE Social Enterprise and WE Day.

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