Final answer:
Enhanced CO₂ levels potentially decrease agricultural productivity in Canada by increasing weed tolerance and biomass, necessitating greater chemical usage for control. Climate change also impacts soil carbon sequestration and global food systems, leading to broader socio-economic issues.
Step-by-step explanation:
Decreased productivity from enhanced CO₂ is indeed considered to be a potential climate change impact on Canadian agriculture.
Research has shown that while certain weeds like Canada Thistle may show increased tolerance and biomass production under elevated CO₂ levels, this can lead to increased dosages and frequency of chemical control to maintain regulation of their population. Additionally, climate change impacts are not limited to control efficacy but extend to broader concerns on global food systems. Soil degradation from overgrazing, erosion, and excessive tilling reduces soil carbon sequestration capabilities, exacerbating climate change. A changing climate severely affects crop yield, potentially triggering a series of socio-economic issues like poverty, hunger, and conflict, thereby indicating a dire need for adaptation in the agriculture industry to mitigate and adjust to these challenges.