Climate solution scams
Unfortunately, the world is also full of people who seem to delight in taking advantage of others. ...est in peculiari inferno, ut pro te.
Perpetual motion, overunity devices, free energy, et al.
(Editor's note: There are, we suppose, legitimate searches for a perpetual motion machines or for machines that can generate power out of nothing, thereby defying the law of thermodynamics. However most that are on the web or the youtubes are completely false, and only out to get your money.)
"Spend enough time on YouTube, and you’ll eventually find yourself in one of the many dark corners hiding within it. No, I’m not talking about the comments. In this case, I mean the many videos dedicated to free energy, overunity devices, perpetual motion machines, or anything else that violates the laws of thermodynamics by trying to get out more energy than is put in. The human race has been reaching for impossible dreams of perpetual motion and free energy for just about all of recorded history. Now it’s convenient to find them all in one place." 
- Example of an over unity scam with a response by a reviewer on quora: "Why is no one concerned about this revolutionary product we are developing that will solve climate change in less than 3 years if popularized?" Answer: This is a simple overunity scam. The sleight of hand comes in where the energy to compress the liquid nitrogen is not counted against the energy produced by his process. Sorry it will take someone else to save the world I guess.