Rising atmospheric carbon dioxide concentrations [CO₂] will cause a multitude of physiological and nutritional changes to rice, one of the most important food crops in the world. Here I review these changes, focusing on the expected decreases in grain nutritional quality and identify stimulation of the Strategy II iron uptake pathway as a promising strategy to increase iron and zinc concentrations in rice grain under ambient and elevated [CO₂]. These results may be applicable to other Strategy II crops such as maize, wheat and barley.

Future atmospheric carbon dioxide levels are likely to double in concentration, affecting agricultural crops, herbivorous insects and the possible progression of various plant diseases. The abundance of insects significantly changed under elevated CO₂ in our study, whereas plant characteristics (phenology, aboveground biomass, foliar nitrogen and carbon contents) and development of fungal plant pathogens did not.

Future food supply from legume crops, such as soybean, will depend on how rising atmospheric carbon dioxide concentrations and drought alter the formation of root nodules in which atmospheric nitrogen is captured. Soybean grown under drought and elevated carbon dioxide produced two to three times more nodules, but that nevertheless overall nitrogen capture by the plants decreased. This was caused by development of nodules in the driest soil layers, and indicates that soybean will be more negatively impacted by global environmental change than previously thought.

Wheat may have different responses to future climates in Australia. Grain yield and biomass under elevated CO₂ increased when the temperature was 2°C higher than the ambient, regardless of irrigation or terminal drought, but not when temperatures were >2°C higher than the ambient. The interaction of elevated CO₂ × temperature × drought should be considered in the new generation of studies on crop adaptation to future climates in Australia.

Elevated CO₂ increases wheat yields, but the variability in response suggests that some lines might respond better than others. We specifically chose lines that we know differ in various adaptive traits, some which might have limited the reponse to elevated CO₂, and found that all lines responded in the same manner. This suggests that the current breeding effort for drought tolerance will not reduce the response to elevated CO₂.

Optimisation of plant responses to increasing CO₂ is a key strategy to achieve future food security. Identification of the leaf level traits that can capture the CO₂ response will be easily adopted for the future wheat breeding programs. This work demonstrates the genetic capacity to adjust the leaf level traits, such as leaf mass per area and leaf nitrogen status to capture the CO₂ response.

Cassava is a staple for over 850 million people, but it is toxic unless properly processed. A monotonous cassava diet often coincides with outbreaks of diseases such as konzo, especially during droughts. The concentration of cyanogenic glucosides in young tubers was 4-fold higher when plants were water stressed, but was lower following re-watering. We conclude that any expansion of cassava into new areas must be accompanied by knowledge of appropriate methods for detoxification, especially in areas increasing in aridity due to climate change.

Seedlings of Eucalyptus saligna Sm. were grown under three CO₂ concentrations (280, 400 or 640 μL L^–1) and two air temperatures (current or current + 4°C). Total plant N uptake scaled with total water use and root biomass across all treatments, suggesting that reductions in tissue N concentration may be attributed to changes in root N uptake by mass flow due to altered transpiration rates.