Where is logos used in Rachel Carson's "The Obligation to Endure"?

When any speaker or writer presents an argument, the speaker uses three elements to appeal to their audience: ethos, pathos, and logos. A speaker uses ethos when they establish themselves as a credible source of information; a speaker uses pathos when they engage the emotions of their audience; a speaker uses logos when they use facts, data, or logic to persuade their audience.

In "The Obligation to Endure," Carson uses logos in a variety of...

When any speaker or writer presents an argument, the speaker uses three elements to appeal to their audience: ethos, pathos, and logos. A speaker uses ethos when they establish themselves as a credible source of information; a speaker uses pathos when they engage the emotions of their audience; a speaker uses logos when they use facts, data, or logic to persuade their audience.

In "The Obligation to Endure," Carson uses logos in a variety of ways. Primarily, she tracks the historical and ecological evidence in America for the last two centuries to explain why, as a nation, the US is so dependent on DDT. She uses specific, concrete details ("The United States Office of Plant Induction alone has introduced almost 200,000 species") as well as expert opinion, such as quotes from Connecticut entomologist Neely Turner.

It is important to remember that ethos, pathos, and logos all work together. When Carson uses logos, she is also appealing to pathos (by shocking us with the damage caused by DDT) and developing her ethos (by proving that she is knowledgeable on the subject).