Examples of the disrespect for, and not just misunderstanding of, science are everywhere. It’s not just those who ignore climate science (alas, at our peril). Here, the author is commenting on how people often disrespect or misrepresent science. "Peril" is a synonym for "doom," "danger," or "risk." "At our peril" is actually more commonly stated as "to our peril," which means the same thing. In this sentence, the author is stating that those who ignore climate science are causing a negative impact on society, because they don't believe the facts. They are continuing to pollute and harm the environment, and encourage others to do so, because they do not believe this will cause climate change. Therefore, they are putting us in "peril," or danger.

At our peril (to be in peril) = at risk of danger, death or other extreme situation. The adjective 'perilous' = something dangerous.