World Refugee Day is here, and Twitter is full of reactions. With #WorldRefugeeDay trending, tweets vary from ones on the Syrian refugee crisis to President Donald Trump’s hard stance against refugees.

As the Natural Resources Defense Council points out though, climate change will only worsen the situation:

In 2016, Major General Munir Muniruzzaman, the chairman of the Global Military Advisory Council on Climate Change told The Guardian that climate change will cause a refugee crisis of an “unimaginable scale.”

And he’s got a point: Since 2008, an average of 22.5 million people have been displaced each year by climate or weather-related events worldwide, according to a 2015 study from the Internal Displacement Monitoring Centre, which monitors displacement globally. By 2050, that number can be anywhere from 50 million to 350 million.

And this displacement is just beginning.

In the United States, climate change won’t produce as many refugees as parts of the Global South, but it will see some. As The New York Times reported in March 2016, Louisiana has already seen the country’s first. Indigenous people living in the state’s Isle de Jean Charles have been allocated governmental funds to move now that climate change is sinking their home. The same goes for some Alaska Natives.

No coastal community is safe from rising waters and proximity to climate change-driven natural disasters like hurricanes. Even non-coastal communities will see disasters like wildfires and droughts make their homes uninhabitable, at worst, and unpleasant, at least.

New Zealand has shown that climate change might be reason enough to allow migrants entry into a country. In 2014, the government granted a Polynesian family of four residency after they filed for refugee status in 2012. The family’s attorney argued that climate change would rob the family of a “safe and fulfilling life,” per court documents, if the government sent them back now that the parents’ visas had expired.

Under Trump, who both doesn’t believe in climate change or letting refugees into the U.S., it’s unlikely America would take a similar stance.