If you want to see a good indicator of change in a system, look to the perimeters of that system over time. Scientists have been doing that with respect to core samples and geological factors at the poles for the past 40 odd years, and the finding is that the North Pole is changing with voracious rapidity.
A few colossal and scary facts (I appreciate they are, in most respects, impossible to adequately internalise, but humour me):
1,000,000 : The amount in square kilometers of global sea ice lost since satellite records began
50% : the decrease in Arctic sea ice since the start of submarine measurements in 1958
5-6 degrees celsius : The increase in winter temperature over the Arctic sea ice since 1950
If these aren’t good indicators of a need for a radical change in our lifestyles then I don’t know what is. All this strange weather we are having is dramatically influenced by weather patterns over the Arctic so if you ain’t sure that the problems of the Arctic are your problems, it might be worth rethinking.