Are there any positive effects of CO₂ increase?

1.  Higher growth rates

One of the more predictable effects of increased levels of carbon dioxide (CO₂) in the atmosphere along with slightly higher temperatures is that crop growth will increase due to the increased efficiency of photosynthesis.

This is known because the greenhouse industry uses artificially elevated CO₂ concentrations and temperatures to increase the growth of horticultural crops such as ornamentals, flowers, and enhance the growth and yield of vegetable crops. While CO₂ is an atmospheric greenhouse gas, it is also a plant nutrient taken in through crop leaves and is a vital building block of photosynthesis.

Carbon dioxide concentration (ppm)

2.  Crop yield increase

Some relatively wealthy countries in temperate regions will likely see crop yields rise, mainly due to longer, warmer growing seasons. Even the excess carbon dioxide in the air that is the underlying cause of climate change can theoretically be a boon for agriculture, acting as a fertilizer when other conditions for plant growth are favourable.

3.  More sugars

An experiment showed that rice, wheat and soybeans made more sugars through photosynthesis at elevated CO₂ levels and produced about 15 percent more seeds.

4.  Less cold related deaths

Climate change will give warmer winters which probably means fewer cold-related deaths in North America and Europe.