And not only that. In order for more biomass to grow due to the increased CO2 levels, the soil must provide nutrients and there must be the right amount of water.
I think you've misunderstood the research. Increased CO2 levels result in increased growth,
in the same type of soil with the same quantities of nutrients and the same amount of water.Under
water-stressed conditions, the increased plant growth due to elevated CO2 levels, is even greater, because of the lower evaporation that takes place as a result of the smaller stomata (pores) on the plants' leaves.
However, it is true that growing crops without returning to the soil all the crop residue and nutrients that are removed when the crop is harvested, will gradually result in less nutritious food.
This is one of the failings of modern agriculture where the soils are constantly tilled and the crop residue removed and used for other purposes. The soils are being gradually depleted of their carbon content, biodiversity and micro-nutrients. The farmers will tend to add only the particular fertilizers that enhance growth, which are mainly Nitrogen, Phosphorus and Potassium. The increased CO2 has no noticeable effect in the open field, because it's increasing at a rate of only one or two parts per million, per year. It's out of sight and out of mind, but its effect on increasing plant growth, although subtle on an annual basis, is continuous and adds up over the years.
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/crop-residues"Crop residues are valuable assets for sustainable management in cropping systems. Residues offer the following: (1) a physical barrier against soil erosion (wind or water), (2) a way to manage GHG emissions, (3) retention of soil moisture at the soil surface; (4) prevention of germination of weeds, (5) snow catchment, and (6) a source of photosynthesized carbon and SOM (soil organic matter). Therefore, effective distribution of crop residues and correct incorporation of them can greatly benefit not only soil biological activities but also can improve soil structure, water infiltration, and workability of the soil and protect it from soil erosion and compaction."Both are not guaranteed as a result of climate change (droughts vs increased precipitation).
Climate is always changing. Didn't you know that, Bart?
There are no guarantees regarding climate or weather. A modestly warming climate, in conjunction with a modest increase in precipitation and a modest increase in CO2 levels sounds fine to me. Whether or not we have the practical commonsense to exploit such benefits, is another issue.
Climate change deniers usually cherry-pick one specific benefit, but deliberately ignore the (more) negative effects that are almost inevitable in a closed-loop ecosystem.
There's an element of truth there; just as climate change alarmists cherry-pick the negative effects and deliberately ignore or downplay the more positive effects.
However, to be precise with our terminology, I've never met an actual 'Climate Change Denier', but I have met many 'Climate Change Alarmists', and it does seem a very obvious fact that the process of creating alarm about CO2 emissions will be much more successful if the positive effects are ignored or downplayed.
We do not live in a controlled laboratory, sheltered from the outside world, but we live as part of a large system that struggles to adapt to the unprecedented pace of change.
I get a sense that many of the scientists expressing alarm about climate change, such as Michael Mann, actually do live in controlled laboratories or offices, working on their computer models, trying to predict the future climate, and really are sheltered from the outside world. I suspect many of them also tend to suffer from OCD (Obsessive Compulsive Disorder).
People who are less sheltered from the outside world, such as farmers, tend to be far more skeptical about the effect of human emissions of greenhouse gases on the climate. Also, the scientists in disciplines which involve more connection to the outside world, such as Meteorology and Geology, tend to express more skepticism about the significance of CO2 in the current warming, presumably because the Meteorologists are more aware of the chaotic and unpredictable nature of weather and climate, and the Geologists are more aware of the history of the planet, its continually changing climate, and previous warm periods that appear to have
preceded rises in atmospheric CO2 levels.
BTW, talking about extreme weather, we are experiencing our third heatwave in 3 months time this year, temperatures have never been this high in the respective months since they were first formally recorded more than 100 years ago. The numbers of excess deaths for this run are not known yet (we have another day and a half to go before normal temperatures set in), but the National Heatplan is in effect again.
If new research were to discover that 200 years ago, or 500 or 1,000 years ago, when CO2 levels were much lower, there had been an even hotter heatwave in your part of the world, would you then change your position on the role of CO2 in the current warm period?