Ok, thanks, Mr. Fang. My homework here:

一項新的研究表明，極端天氣正在導致墨西哥和美國之間無證人員的移入和返回，這表明隨著氣候變化加劇幹旱、風暴和其他困難，更多的移民可能會冒著生命危險穿越邊境。

 

A new research shows that extreme weather is/ was causing the to-and-fro of undocumented immigrants between Mexico and United States (Or was causing the migration and return of undocumented immigrants) , indicating that more immigrants will risk their lives to cross the borders as the weather exacerbates the drought, storms and other difficulties.