Check out this answer from Consensus:
Rising atmospheric CO2 has the potential to spur plant growth and benefit future food production, but the extent of these benefits is subject to significant variability and uncertainty. Continued research and adaptive agricultural practices will be essential to harness the positive effects of elevated CO2 while mitigating its challenges.
The increasing concentration of atmospheric carbon dioxide (CO2) is a significant aspect of climate change that has profound implications for plant growth and agricultural productivity. This article explores whether rising CO2 levels will spur plant growth and benefit future food production, drawing on findings from recent research.
CO2 and Plant Growth
Elevated CO2 levels can enhance photosynthesis and reduce plant water use, potentially increasing crop yields. Studies have shown that CO2 enrichment generally stimulates plant growth and yield across various scales, from biochemical processes to agro-ecosystems6 8. For instance, a meta-analysis of free-air CO2 enrichment (FACE) experiments confirmed that elevated CO2 increases light-saturated carbon uptake, diurnal carbon assimilation, growth, and above-ground production3.
Crop-Specific Responses
Different crops respond variably to elevated CO2. For example, wheat yields have been shown to increase by 26% under elevated CO2, primarily due to an increase in grain number4. Similarly, vegetables exhibit a 34% yield increase under elevated CO2, although the response varies among different types of vegetables5. However, the response is not uniform across all crops; C4 species, for instance, show little response compared to C3 species3.
Regional Disparities
The beneficial effects of rising CO2 on crop water productivity (CWP) are not uniformly distributed across regions. Research indicates that arid regions may experience more significant increases in CWP, potentially mitigating global yield losses and reducing agricultural water use2. This regional variability underscores the importance of considering local growing conditions when assessing the impact of elevated CO2 on food production.
Limitations and Challenges
Despite the potential benefits, there are limitations and challenges associated with elevated CO2. For instance, the non-linear response of wheat yield to CO2 suggests that yield stimulation levels off at higher CO2 concentrations4. Additionally, elevated CO2 can inhibit nitrate assimilation in shoots while enhancing it in roots, which may affect overall plant productivity and food security7. Moreover, long-term experiments have shown that the initial positive response to elevated CO2 may diminish over time, complicating predictions for future crop production10.
Implications for Future Food Production
The implications of rising CO2 for future food production are complex. While elevated CO2 can enhance crop yields and water-use efficiency, the extent of these benefits is influenced by various factors, including crop type, regional conditions, and long-term environmental changes. Therefore, strategies to ensure future food security must consider these variables and incorporate adaptive measures to optimize the benefits of elevated CO21 6.
Will rising CO2 spur plant growth and therefore benefit future food production?
Christopher Skinner has answered Unlikely
An expert from University of Michigan in Climatology, Atmospheric Science
The statement oversimplifies what we know about CO2 and its effects on vegetation. To project how plant growth will respond to rising CO2, we need to consider the direct and indirect effects of CO2 on plants. When both effects are considered, it is clear that the negative impacts of rising CO2 on plants will outweigh the positive impacts in many regions of the world.
The direct effect of rising CO2 on vegetation does enhance photosynthesis in many plant types. This effect is referred to as CO2 fertilization. Eventually, the CO2 fertilization effect saturates because of other growth-limiting factors (e.g. nitrogen, phosphorus, water, etc.). Farmers can reduce the negative impacts of these growth-limiting factors by increasing the application of fertilizer and irrigation. Therefore, given sufficient access to fertilizer and irrigation, we do expect that the direct effect of CO2 will lead to enhanced crop yield in a higher CO2 world (for most crops). However, crop nutritional value exhibits an inverse relationship with the atmospheric CO2 concentration during growth (i.e. plants are less nutritious when CO2 increases).
The indirect effect of rising CO2 on vegetation largely reduces plant growth. Higher CO2 increases atmospheric temperatures. Warmer temperatures increase the frequency and intensity of heat extremes such as heat waves, and enhance evaporative demand from the soil, both of which negatively impact plant growth. Rising atmospheric CO2 can also disrupt the timing of agriculturally important climate phenomena such as monsoon rain onset, reducing crop yield.
Will rising CO2 spur plant growth and therefore benefit future food production?
Dorota Komar has answered Unlikely
An expert from National Institute of Investigation and Agrary Technology and Alimentary in Plant Biology
The answer is: not really. It is true that elevated CO2 boosts photosynthesis and by that biomass production. Unfortunately, the climate change that we are now experiencing is called “global warming” not without a reason. Global warming means that the temperatures will rise and there will be precipitation shift. As a result it will be warmer, it will rain more in some places and less in others. Plants will need to fight with drought and heat.
At the beginning scientists thought the negative effect of increased temperature will be balanced by elevated CO2 atmospheric concentration. However, later works revealed that the effect of elevated CO2 will not be sufficient. (READ: Long et al.: Food for Thought: Lower-Than-Expected Crop Yield Stimulation with Rising CO2 Concentrations. Science 30 Jun 2006).
There is still quite a discussion what will be an exact outcome. Depending on the simulation, the situation change a bit (READ: Abigail et al.: Plant responses to increasing CO2 reduce estimates of climate impacts on drought severity. PNAS September 6, 2016 – for the recent prediction of the strenght of the CO2 balancing effect. READ: Rosenzweig and Parry: Potential impact of climate change on world food supply. Nature 13 January 1994; Mora et al.: Suitable Days for Plant Growth Disappear under Projected Climate Change: Potential Human and Biotic Vulnerability. PLOS 10 June 2015 to see the projections).
But the outcome everyone agrees with is:
- the effect of elevated CO2 will not be enough to balance production looses caused by the climate change
- while in countries like Canada or Russia, plant production will be boosted (now there is cold and the conditions are too hard for most of the crops), in most, including countries that nowadays base mostly on plant production (Africa, South America), plant productivity will be decreased
- adaptation in breeding process and type of crops will be needed, especially in temperate climate zone
Will rising CO2 spur plant growth and therefore benefit future food production?
Alexander Cheesman has answered Unlikely
An expert from James Cook University in Climatology, Biology, Plant Ecology
Multiple experiments looking at the impacts of increased CO2 concentrations suggest that the answer is much more complicated than represented by Congressman Lamar Smith. Although in the short term there may be a direct benefit to elevated CO2, this is often offset by a progressive nutrient limitation (e.g Nitrogen) and/or acclimation in photosynthesis and leaf architecture of plants. There may certainly be some benefits in requiring less water to grow the same quantity of food under elevated CO2 – however the ‘quality’ of that food may be limited by nutrient availability. Similarly the prevalence of much higher temperatures and potential catastrophic droughts in a high CO2 world make it far from clear how farming production will be impacted.
Will rising CO2 spur plant growth and therefore benefit future food production?
Jianwei Li has answered Likely
An expert from Tennessee State University in Environmental Science, Soil Science, Biogeography
The positive effect may be ephemeral and will be eventually limited by other nutrients such as nitrogen and phosphorus, which are unfortunately very common limiting factors for plant growth.
Will rising CO2 spur plant growth and therefore benefit future food production?
Johan Uddling has answered Extremely Unlikely
An expert from University of Gothenburg in Plant Biology, Ecology, Environmental Science
The first part is correct; increased CO2 stimulates photosynthesis and growth. The second part is wrong; food quality declines in higher CO2. The nutritional quality in terms of concentrations of protein and nutrient elements such as iron and zinc is significantly decreased in plants grown under increased CO2 concentrations (those projected for later during this century).
Will rising CO2 spur plant growth and therefore benefit future food production?
Mary Heskel has answered Extremely Unlikely
An expert from Macalester College in Plant Ecology, Ecophysiology, Ecology
Under CO2 fertilization experiments, where CO2 is added to the air above plant canopies, there is often an increase in photosynthesis and growth in the short term. However, longer term observations show a declining effect over time, often due to limiting nutrients, such as nitrogen and phosphorus. A higher-CO2 world will also likely be warmer, and have more high temperature events and droughts; these combined effects will likely effectively counter the potential fertilization effect that CO2 has on photosynthesis. Additionally, recent studies have shown that high CO2 environments may spur growth of some plant organs (leaves), but not all (fruits); and elevated CO2 can cause declines in nutritional content of food (as see in this meta-analysis: https://www.nature.com/articles/nature13179).
Will rising CO2 spur plant growth and therefore benefit future food production?
Ruediger Grote has answered Likely
An expert from Karlsruhe Institute of Technology in Plant Ecology, Forestry Sciences
CO2 is indeed a resource for plants and is therefore applied in greenhouses to increase growth and fruit production since decades. However, in the field, effects on plants have been less clear with observations showing higher, lower or no growth response at all. If growth responses are positive, the effect seems to decline with time (Körner 2006). Thus, the general theory today is that positive growth responses depend on the availability of other resources such as water and nitrogen (e.g. Long et al. 2006, Terrer et al. 2018). The problem is that rising CO2 is connected to the greenhouse-effect, which results in warming and is likely to increase the probability for drought stress – leading to regionally very differentiated results (e.g. Schlenker et al 2006).
Körner, C., 2006. Plant CO2 responses: an issue of definition, time and resource supply. New Phytol. 172, 393-411.
Long, S.P., Ainsworth, E.A., Leakey, A.D.B., Nösberger, J., Ort, D.R., 2006. Food for Thought: Lower-Than-Expected Crop Yield Stimulation with Rising CO2 Concentrations. Science 312, 1918-1921.
Terrer, C., Vicca, S., Stocker, B.D., Hungate, B.A., Phillips, R.P., Reich, P.B., Finzi, A.C., Prentice, I.C., 2018. Ecosystem responses to elevated CO2 governed by plant–soil interactions and the cost of nitrogen acquisition. New Phytol. 217, 507-522.
Schlenker, W., Hanemann, W.M., Fisher, A.C., 2006. The Impact of Global Warming on U.S. Agriculture: An Econometric Analysis of Optimal Growing Conditions. The Review of Economics and Statistics 88, 113-125.