The linked references indicates that continued global warming will likely decreases terrestrial plants ability to absorb CO2, and also to decrease the nutritional value of the plants that do grow:
Camilo Mora, Iain R. Caldwell, Jamie M. Caldwell, Micah R. Fisher, Brandon M. Genco, Steven W. Running (June 10, 2015), "Suitable Days for Plant Growth Disappear under Projected Climate Change: Potential Human and Biotic Vulnerability", PLOS, DOI: 10.1371/journal.pbio.1002167
http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002167Abstract: "Ongoing climate change can alter conditions for plant growth, in turn affecting ecological and social systems. While there have been considerable advances in understanding the physical aspects of climate change, comprehensive analyses integrating climate, biological, and social sciences are less common. Here we use climate projections under alternative mitigation scenarios to show how changes in environmental variables that limit plant growth could impact ecosystems and people. We show that although the global mean number of days above freezing will increase by up to 7% by 2100 under “business as usual” (representative concentration pathway [RCP] 8.5), suitable growing days will actually decrease globally by up to 11% when other climatic variables that limit plant growth are considered (i.e., temperature, water availability, and solar radiation). Areas in Russia, China, and Canada are projected to gain suitable plant growing days, but the rest of the world will experience losses. Notably, tropical areas could lose up to 200 suitable plant growing days per year. These changes will impact most of the world’s terrestrial ecosystems, potentially triggering climate feedbacks. Human populations will also be affected, with up to ~2,100 million of the poorest people in the world (~30% of the world’s population) highly vulnerable to changes in the supply of plant-related goods and services. These impacts will be spatially variable, indicating regions where adaptations will be necessary. Changes in suitable plant growing days are projected to be less severe under strong and moderate mitigation scenarios (i.e., RCP 2.6 and RCP 4.5), underscoring the importance of reducing emissions to avoid such disproportionate impacts on ecosystems and people."
Also see:
http://time.com/3916200/climate-change-plant-growth/Extract: "Climate change could turn forests them into carbon emitters
Add the hindering of plant growth to the long and growing list of the ways climate change may affect life on our planet. The number of days when plants can grow could decrease by 11% by 2100 assuming limited efforts to stall climate change, affecting some of the world’s poorest and most vulnerable people, according to a new study in PLOS Biology.
Climate change affects a number of variables that determine how much plants can grow. A 7% decline in the average number of freezing days will actually aid plant growth, according to the study, which relied on an analysis of satellite data and weather projections. At the same time, extreme temperatures, a decrease in water availability and changes to soil conditions will actually make it more difficult for plants to thrive. Overall, climate change is expected to stunt plant growth.
Declining plant growth would destroy forests and dramatically change the habitats that are necessary for many species to survive. And, if conditions get bad enough, forests could actually produce carbon instead of removing it from the atmosphere, exacerbating the root cause of climate change.
“Those that think climate change will benefit plants need to see the light, literally and figuratively,” said lead study author Camilo Mora, a professor at the University of Hawaii, in a statement.
The effects of climate change on plant growth will likely vary by region, with northern areas in places like Russia, China and Canada gaining growing days. But already hot tropical regions could lose as many as 200 growing days per year. In total, 3.4 billion people would live in countries that lose nearly a third of their growing days. More than 2 billion of those people live in low-income countries, according to the study.
The researchers’ findings sound pretty dire, but they acknowledge that these consequences would be the result of a worst-case scenario of sorts, one in which humans take minimal action to stem climate change. With strong or even moderate efforts, worldwide plant growth will fare much better, according to the study."
Feng, Z., Rütting, T., Pleijel, H., Wallin, G., Reich, P. B., Kammann, C. I., Newton, P. C.D., Kobayashi, K., Luo, Y. and Uddling, J. (2015), Constraints to nitrogen acquisition of terrestrial plants under elevated CO2. Global Change Biology. doi: 10.1111/gcb.12938
http://onlinelibrary.wiley.com/doi/10.1111/gcb.12938/abstractAbstract: "A key part of the uncertainty in terrestrial feedbacks on climate change is related to how and to what extent nitrogen (N) availability constrains the stimulation of terrestrial productivity by elevated CO2 (eCO2), and whether or not this constraint will become stronger over time. We explored the ecosystem-scale relationship between responses of plant productivity and N acquisition to eCO2 in free-air CO2 enrichment (FACE) experiments in grassland, cropland and forest ecosystems and found that: (i) in all three ecosystem types, this relationship was positive, linear and strong (r2 = 0.68), but exhibited a negative intercept such that plant N acquisition was decreased by 10% when eCO2 caused neutral or modest changes in productivity. As the ecosystems were markedly N limited, plants with minimal productivity responses to eCO2 likely acquired less N than ambient CO2-grown counterparts because access was decreased, and not because demand was lower. (ii) Plant N concentration was lower under eCO2, and this decrease was independent of the presence or magnitude of eCO2-induced productivity enhancement, refuting the long-held hypothesis that this effect results from growth dilution. (iii) Effects of eCO2 on productivity and N acquisition did not diminish over time, while the typical eCO2-induced decrease in plant N concentration did. Our results suggest that, at the decennial timescale covered by FACE studies, N limitation of eCO2-induced terrestrial productivity enhancement is associated with negative effects of eCO2 on plant N acquisition rather than with growth dilution of plant N or processes leading to progressive N limitation."
Also see:
http://thinkprogress.org/climate/2015/06/13/3669094/carbon-dioxide-could-mean-less-nutritious-plants/
