In rhetoric or logical argumentation, a slippery slope fallacy is according to Ian B. Johnson:

The Slippery Slope also might well be called the “Appeal to Fear.” It shows a proposition to be unacceptable by first stating that acceptance of the proposition will lead to an unacceptable result, then stating that the unacceptable result will in turn lead to an even more unacceptable result. The chain may continue through several steps and will lead to an end result that is very clearly unacceptable. The real problem with the slippery slope is that none of the steps in the chain need to be proven for the argument to persuade most partisans who are looking for a reason to be persuaded; instead, each step merely needs to sound reasonable in isolation.

Now consider this headline from LiveScience.com:  Antartic Meltdown would Flood Washington, D. C. Well not before all the penguins and polar bears die of heat exhaustion, and all the people on the planet are going to be fried by that time not to mention the dolphins which will be boiled to death:  “if you had hot water poured on you, you would flee, wouldn’t you?”

This blog suggests there’s nothing to worry about, but I don’t have the time to work out the math.