Hundreds of scientists told President Trump on Thursday to leave a United Nations climate agreement, arguing that carbon dioxide was "environmentally helpful" and not a "pollutant."

Massachusetts Institute of Technology climate researcher Dr. Richard Lindzen led the group of 300 scientists who sent the letter to Trump on Thursday. Leaving the United Nations Convention on Climate Change would hamper the United States' cooperation with the 2015 Paris Climate Agreement, according to the Washington Examiner.

The scientists are arguing against the view that carbon dioxide polluted the atmosphere, saying it helps "crops and other plants that nourish all life."

"There is clear evidence that increased atmospheric carbon dioxide is environmentally helpful to food crops and other plants that nourish all life. It is plant food, not poison," the letter reads.

The letter also criticizes previous government actions to address climate change as scientifically unjustified.

"Since 2009, the U.S. and other governments have undertaken actions with respect to global climate that are not scientifically justified and that already have, and will continue to cause serious social and economic harm — with no environmental benefits," the scientists wrote.

UPDATE February 25, 3:10 P.M.: This post was updated to correct the name of Dr. Richard Lindzen. The original version incorrectly referred to him as Dr. Mark Lindzen.