The DIFFERENCE between the temperature of the equator (warm) and the temperature of the arctic (cold) creates the Jet Stream, the slightly undulating winds that move our weather from west to east.
Professor Francis explains that as we heat our planet due to global warming, the arctic heats up faster than the equator. Because the DIFFERENCE between the arctic temp and the equator temp is less, and we get two results: (1) the Jet Stream is slower, and, (2) the Jet Stream undulates more, it is WAVIER. Bad weather will tend to stay around longer. We may be more vulnerable to hurricanes in NYC.
Check out her short video (5 min) here: CLICK.