So does the polar vortex we've been hearing about disprove global warming, or was it caused by climate change?
It's important to remember the difference between regional and global weather; there can be considerable variations in local/regional weather that are not representative of global weather trends. Plus, no single pattern proves or disproves long term trends. Global climate change, or warming, has affected the Arctic most...warming it and leading to shorter 'ice' seasons with thinner ice. That has decreased the contrast in temperatures between the mid-latitudes, where we live and the Arctic...which in turn shows signs of weakening the jet stream circling the Arctic and tending to 'bottle up' the coldest air. That would allow more frequent surges of Arctic air southward. While much research remains to be done, such strong Arctic outbreaks are not at all inconsistent with observed climate change trends.