We are plagued by sensationalized pseudo-science as researchers pander to political hysterics in hopes of gaining favor and funds. It has always been so, but it seems worse than in the past. Consider this:

Elevated CO2 is considered to be a serious catalyst of global change. Its effects can be felt throughout the ecosystem, including the insect-plant food chain link. Safeguarding highly-usable crops is of great importance to many local and national economies.

Many plants have inherent enzyme-based defenses that are released during insect attack. This study found that when soybeans (Glycine max) were exposed to elevated amounts of CO2 the plants became more susceptible to attack by Japanese beetles (Popillia japonica). Furthermore, as these beetles consumed the weakened soybeans, the insect’s invasive abilities were intensified.

This sounds preposterous. Why would plants become less able to defend themselves when a major nutrient (CO2) is in ample supply? It may be that this is false.

The model explains observed CO2 responses of photosynthesis, production and LAI in four forest free air CO2 enrichment (FACE) experiments. Insensitivity of LAI except at low LAI, increase in light-use efficiency, and photosynthetic down-regulation (as a result of reduced leaf N per area) at elevated CO2 are all explained through the combined effects on a and leaf quantum efficiency.

It isn't that elevated CO2 weakens soya so much as that the balance of nutrients matters. This is sensible, and well known if not perfectly understood. Balanced fertility increases plant health and yield. An excess or a deficiency for any nutrient gives lesser results.

This is further complicated by variable plant characteristics. Some cultivars do better than others though growing conditions are identical. This is why locally adapted cultivars matter. In the wild, over time, those that do better come to dominate. Crop plants grown from commercial seed don't have this adaptive process since the seeds are produced elsewhere from plants growing in different conditions.

As CO2 concentrations change so must agronomic practice. It seems that plants will be able to use more primary and secondary nutrients as they grow more quickly in a CO2 rich environment. Other work has shown that they also use less water since they evapotranspire less as fewer stomata are needed to get enough CO2 from the air.

Some cultivars will do better than others, so seed producers as well as growers can profit from attention to these changes. Researchers could help by doing better designed experiments that yield useful information rather than sensationalized nonsense.