In a temperate zone, growth may be limited by extremely low temperatures and extremely low precipitation. The growth in tree rings in this area is usually complacent, so periods of drought or cold will stand out. Since the industrial revolution, there has been a well-recorded large increase in the amount of carbon dioxide.
Carbon dioxide is essential for plant growth.
As, everyone knows carbon dioxide is also a major greenhouse gas and the increased emissions may be adversely affecting the world's climate. However, the net warming effect on climate may be beneficial to plant growth. I believe that the increase in carbon dioxide emissions have had a positive effect on the growth of trees and this positive effect will negate any periods of drought or excessive coldness that might otherwise have hindered tree growth. Forest have been known be a carbon sink. Through the burning of fossil fuels and wood the amount of greenhouse gases have increased somewhat constantly since the industrial revolution.