Final answer:
Increased productivity from warmer temperatures is a potential impact of climate change on Canadian agriculture, but it's a complex issue with mixed results. Initial increases in productivity have been counteracted by droughts and the changing climate poses broader risks to agriculture beyond just temperature effects.
Step-by-step explanation:
Climate change indeed has varying impacts on agriculture, including the potential for increased productivity due to warmer temperatures. However, this effect is not uniformly positive or guaranteed. As global temperatures rise, ecosystems and habitats are altered, leading to shifts in the balance of many biomes and the organisms within them.
While warmer temperatures initially led to an increase in plant productivity in the 1980s and 1990s, the benefits are now often offset by increased frequency of droughts, reducing the growing season and increasing the risk of low productivity. Furthermore, milder winters can fail to kill pests, leading to greater infestations and subsequent damage to crops.
Rather than a straightforward increase in productivity, climate change presents a complex scenario where crop yields could be positively or negatively affected depending on a variety of factors including temperature increases, changes in precipitation patterns, the balance between photosynthesis and respiration, and environmental stressors such as drought.
The interconnected nature of the global food system means that any impact on crop yields due to climate change can have wide-ranging effects, potentially triggering cascades of issues like poverty, hunger, civil conflict, and migration. Therefore, while increased productivity might be seen in some areas or for certain periods, it is essential to recognize the broader implications of a changing climate on agriculture and prepare for adaptive measures in food production systems.