Check out my website on this issue at: https://globalwarmingeducationfoundation.wordpress.com/
As for colder weather being disproof of global warming take a good look at the temperatures on Goddard Institute maps in the last winter month:
GISS temperature anomaly map for February of 2015. Temperature bar is in degrees Celsius.
Less than 2% of the Earth's surface was colder than average. Also check out the intensity of the warmest color at the lower bar at 15.5 degrees Fahrenheit above normal (8.6 Celsius). Global warming is concentrated in the Arctic regions.
People tend to think that what happens in their backyards must be happening all over.