So what does this logo mean anyway?
The logo’s network of 192 blue lines (based on graphs of climate data)—one for each UN member state—alludes to the complexity and inclusivity of the climate question. Over 269 designs were entered. Designers Troels Faber and Jakob Wildschiødtz won DKK 100,000 (around USD $20,000) for their efforts.
The color was adjusted to a blue darker than the traditional UN blue, which I think looks far better.
P.S. COP stands for Conference of the Parties.