Leaves falling in autumn

Climate change is real and I used to think that once we loose winter, the trees would have leaves all year round which would reduce the amount of CO2 in the atmosphere quicker.

My assumption was based on the fact that trees looses their leaves due to cold temperature but that is not the case. Leaves die out due to the shorter days which mean that even if our winters would be warm, our trees would not have leaves. See below:

"Despite the traditional belief, weather plays no role. The trees possess an inner clock which is triggered by the length of the daylight. The shrinking daylight in autumn activates it, and the trees will lose their leaves even in the warmest falls."
-Softpedia

For more, check out this site:
http://news.softpedia.com/news/Why-Do-Leaves-Fall-Off-in-Autumn-45440.shtml