Every day brings a new report on some obscure impact of climate change by 2050. Today's headline is almost comical, "Chipotle Warns It Might Stop Serving Guacamole If Climate Change Gets Worse". Along the same lines, a typical example of a news story about the impact of global warming is the claim that "climate change may cause major lizard extinctions by 2050". The cacophony of claims about all the catastrophic events that may occur by 2050 become little more than white noise to climate change deniers and skeptics.
Here is the climate change impact that most resonates with climate change skeptics. "The sea level is rising by 1/10" per year".
It may be that the sea level rise of 1/10 inch per year is such a slow trend and is so lacking in shock value that it is not much of a headline generator. However, it's easy to understand and fairly linear. It's also one of the most worrisome aspects of the millions of metric tons of greenhouse emissions gases being emitted annually.
Here is another tactic to take with global warming skeptics. Make a wager that 2015 will be the warmest in recorded history. If James Hansen is correct, you have a good chance of winning the wager, and it refutes the denialism that has been fomented due to the decade long pause in the increase in global surface temperatures
And for those living in areas of the U.S. that have suffered through a brutally cold winter, suggest they visit this site that shows the global temperature departure from average. The maps on this site visually show that while some geographies are unusually cold, they are more than compensated by areas that are unusually warm.
Global warming deniers may try to refute the fact that the seas are rising. Of course, many of the same folks will tell you that dinosaur fossils were put here to test our faith. However, I'll take the word of NASA scientists that confirm that the sea level is rising. If the folks at NASA are good enough at math that they can put a man on the moon, I trust their capability to measure the rising sea level