Actually, CO2 does cause measurable warming. The warming effect is not huge, and not worrisome, but it is not zero, and it is large enough to be measurable.

There really is no question about the fact that the Earth's average temperature has warmed slightly, as CO2 levels have risen, over the last six decades. The magnitude of that change is debatable: different "global" composite temperature indices vary in their measured trend by approximately a factor of two. But none of them show zero trend.

The "climate sensitivity" of the Earth's temperatures to changes in CO2 level can be estimated by careful comparison of measured temperatures to measured CO2 levels. Here's an example on my web site, showing how that can be done:

https://sealevel.info/sensitivity.html

Climate change is a highly politicized issue, so, as is the case for any politicized issue, if you want to understand it you need to seek out balanced information. If you want to learn about the SCIENCE of climate change, instead of political spin, here's a list of resources which can help:

https://tinyurl.com/learnmore4

It has:

● accurate introductory climatology information

● in-depth science from BOTH skeptics & alarmists

● links to balanced debates between experts on BOTH sides

● information about climate impacts

● links to the best blogs on BOTH sides of the issue

Conservatives stand for honesty, integrity, morality, and steely-eyed realism. We hold our opinions because we are confident that they are correct, we have the confidence in them to encourage free and open debate, and if our opinions are shown to be wrong we gratefully accept the correction of our errors.

Modern liberalism (not to be confused with classical liberalism) is the opposite. It is characterized by dishonesty and immorality (both typically excused with the platitude that "everybody does it"), self-delusion, and a reflexive resort to censorship and worse. ("Inside every progressive is a totalitarian screaming to get out." -David Horowitz)

You see that in the climate debates, where leftists (climate activists) have repeatedly been caught manipulating, withholding, exaggerating, or even fabricating evidence, flouting the law, blackballing skeptics, and censoring contrary viewpoints, to promote the CAGW scare. The major blogs, publications, and institutions which climate activists control are ruthlessly censored, to suppress dissent.

In stark contrast, the most prominent conservative (climate realist) blogs and institutions actively encourage open discussion and dissent. That's why, for example, WUWT is so obviously and strikingly superior to any of the leftists' climate blogs.

Unfortunately, some people who call themselves "conservative" don't act like it. I'm tired of self-identified conservatives, like Michael Shannon, raging about Republicans' lack of conservatism, while they, themselves, behave like liberals.

If Mr. Shannon were really a conservative, he wouldn't censor his blog, to suppress expression of opinions different from his own. Unfortunately, that's exactly what he does. That's why you don't see the following comment in the comments section, on this article:

· ‍‍‍‍‍‍ ‍‍

Your comment is awaiting moderation.

1.If conservatives can’t win Republican primaries, they certainly cannot hope to win as third-party candidates running against both Republicans and Democrats.

2.If so-called “conservatives” don’t care about anything but money, they’re no more conservative than the country clubbers whose Republican identity is based entirely on their desire for low taxes.

There’s something very, very wrong with a 785-word rant accusing Republicans of being “morally corrupt,” which talks almost exclusively about… money. In 785 words you devoted a grand total of three words to a passing mention of moral issues.

One in four American babies die by “choice,” but you never mentioned it.

The courts have spent the last eighty years brazenly lying to impose progressive agendas, and trampling the nation’s fifty-one constitutions in the process, yet now, for the first time in eight decades, honest jurors might actually have a slender majority on the SCOTUS, but you never mentioned it.

The American family is in tatters, with 39.6% of babies born out of wedlock in 2018, but you used the word “family” just once, and never mentioned illegitimacy.

The academy has been mostly taken over by far-left crackpots and atheists, who do everything in their power to crush all dissent, who enforce values antithetical to Christian morality, and who have created entire disciplines dedicated to promoting leftist lunacy, but you never mentioned it.

Academics expose corruption in Grievance Studies

Etcetera, etcetera, etcetera

The misallocation of federal monies is a real problem, but it is far from the only problem, it is far from our most important problem, and it is only peripherally a moral issue. If you’re going to editorialize about moral corruption, you should talk about morality, not just money.

That's not the only upside.

Elevated CO2 levels make plants healthier and more productive. That's why commercial greenhouses use CO2 generators to raise daytime CO2 levels, typically to about 1500 ppmv. That's far higher than we could ever hope to drive outdoor CO2 levels by burning fossil fuels.

Rising CO2 levels have increased global agricultural yields by about 20%. Without that improvement, mankind could approximately make up the difference by planting more land. If all the world's tropical and temperate rainforests were put to agricultural use, that would just about make up the difference.

However, rising CO2 levels also make plants more water-efficient and drought-resistant, by improving stomatal conductance relative to transpiration. That's one of the reasons that droughts are now less damaging to crops, and one of the causes for the sharp decline in drought-triggered famines.

Here are a couple of references:

● http://tinyurl.com/CO2droughtstress

● http://www.ncbi.nlm.nih.gov/pubmed/26929390

This is disinformation. It denies a full century of consistent results, from thousands of scientific studies. eCO2 is extremely beneficial for the vast majority of crops. For most crops, the benefits of additional CO2 do not begin to diminish until levels exceed 1200 ppmv, which is far above what they could ever reach due to fossil fuel use. So, practically speaking, there is no "tipping point" beyond which rising CO2 levels cease to be beneficial.

Rice is a C3 plant. Like all C3 crops it benefits dramatically from eCO2:

Here's a FACE (Free Air CO2 Enrichment) study of rice. They compared 380 ppmv CO2 to 550 ppmv CO2, and found a 30% grain yield improvement.

A great university like OSU should be embarrassed to have its name associated with the level of misinformation in this article.

This is utter nonsense.

Agronomists have conducted thousands of studies of the effects of varying CO2 levels on crops. Many of those studies also tested the effects of other changes, such as temperature, moisture & nutrient levels. The results are irrefutable: the vast majority of plants benefit tremendously from eCO2, to levels far above what they can ever reach due to burning fossil fuels.

These plants evolved when CO2 levels were much higher than now, and they don't need any "time to adapt" to the conditions that they are already best suited for.

This is also the exact opposite of the truth. eCO2 is especially beneficial to crops in hot and arid conditions. For instance, here’s a paper about how eCO2 benefits wheat, especially in hot, dry conditions:

Fitzgerald, G. J. et al (2016). Elevated atmospheric [CO2] can dramatically increase wheat yields in semi-arid environments and buffer against heat waves. Glob Change Biol, 22: 2269-2284. doi:10.1111/gcb.13263

This is the opposite of the truth. By making plants faster-growing and healthier, eCO2 helps them withstand adverse conditions, like droughts, and insects. For instance, this paper reports that higher CO2 levels improve the ability of pine trees to resist damage from pine bark beetles:

K.A. Novick et al (2012)). Increased resin flow in mature pine trees growing under elevated CO2 and moderate soil fertility. Tree Physiology, Vol. 32, Issue 6, June 2012, pp. 752–763. doi:10.1093/treephys/tpr133

Actually, most studies have found that eCO2 increases, rather than decreases, antioxidants in food crops.

This is a red herring. Inadequate fixed nitrogen reduces protein production relative to carbohydrate production in crops, because proteins contain nitrogen and carbohydrates don't. However, legumes like alfalfa and soybeans fix their own nitrogen from the air, and the benefits of eCO2 for legumes are especially large.

Here's a video which compares legume seedlings grown at two different CO2 concentration levels:

https://www.youtube.com/watch?v=P2qVNK6zFgE

Most crops grown for their protein content are legumes, so eCO2 is actually net beneficial for supplying protein.

That is untrue.

Vitamin C levels are not adversely affected by elevated CO2. In fact, most studies have found that eCO2 increases vitamin C and antioxidant levels in crops.

If soil is deficient in "micro-nutrients" like iron and zinc, then more productive crops may have lower levels of those nutrients—but not lower total amounts.

However, dietary shortages of both of those micro-nutrients are easily resolved through fertilization or very inexpensive nutritional supplementation. In the case of iron, it can be as simple as cooking in cast-iron pots.

It is possible to contrive growing conditions in which something other than CO2 limits plant growth and health, or in which a shortage of some soil nutrient causes better crop yields to be accompanied by reduced levels of some micro-nutrient, but such contrived conditions are easily avoided through normal fertilization practices.

Under real-world conditions, additional CO2 is dramatically beneficial for agriculture, to levels far beyond what we can ever hope to reach in the outdoor atmosphere, and the nutrient value of crops grown with extra CO2 is not significantly different from other crops.

In 1850 CO2 levels averaged about 285 ppmv (0.0285%). By 2018 CO2 levels had risen to about 408.5 ppmv, a 43.3% increase. That's nowhere near "nearly double."

This is the enormously misleading "nutrient scare."

That the nutrient scare is nonsense should be obvious if you consider that food grown in greenhouses at 1500 ppmv CO2 is every bit as nutritious as food grown outdoors at ambient CO2 levels (which currently average about 411 ppmv).

If elevating CO2 by nearly 1100 ppmv doesn't cause crops to be less nutritious, then elevating CO2 by a small fraction of that won't, either.

The nutrient scare is an attempt to put a negative "spin" on an enormous benefit of elevated CO2 (eCO2): that it improves crop yields.

Faster-growing, more productive crops require more nutrients per acre, though not more nutrients per unit of output. Inadequate nitrogen fertilization reduces protein production relative to carbohydrate production, because proteins contain nitrogen and carbohydrates don't. Likewise, low levels of iron or zinc in soils will result in lower levels of those minerals in some crops. These facts are well-known, and unremarkable.

So, it is possible, by flouting well-established best agricultural practices, to contrive circumstances under which eCO2, or any other factor that improves crop yields, reduces levels of protein or micronutrients in crops.

Farmers know that the more productive crops are, the more nutrients they need, and competent farmers fertilize accordingly. (Or, for nitrogen, they may plant nitrogen-fixing legumes — which, fortunately, benefit greatly from extra CO2.)

If you don’t fertilize according to the needs of your crops, the negative consequences may include reductions in protein and/or micronutrient levels in the resulting crops. The cause of such reductions is not higher CO2 levels, the cause is poor agricultural practices.

Mathematician Irakli Loladze and Dr. Samuel Myers are the two most prominent promoters of the nutrition scare, and Dr. Loladze admitted to me that food grown in greenhouses with dramatically elevated CO2 levels is as nutritious as food grown outdoors at low CO2 levels, because adequate fertilization mitigates the potential problem.

3000 ppmv (µmol/mol) CO2 is absurdly high. Ambient outdoor CO2 levels are unlikely to ever reach even 800 ppmv, from burning fossil fuels. Even commercial greenhouses which use CO2 generators to enhance CO2 levels and crop productivity, rarely use CO2 levels above about 1600 ppmv. So testing with levels at 3000 ppmv, while interesting, provides no practical insights.

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This is the enormously misleading "nutrient scare."

The absurdity of the nutrient scare nonsense should be obvious if you think about a simple fact: food grown in greenhouses at 1500 ppmv CO2 is every bit as nutritious as food grown outdoors at ambient CO2 levels (which currently average about 411 ppmv).

If elevating CO2 by nearly 1100 ppmv doesn't cause crops to be less nutritious, then elevating CO2 by only 140 ppmv wouldn't, either.

(However, the article's claim that CO2 levels will reach 550 ppmv by mid-century is also false. They're on track to reach only about 490-500 ppmv by 2050.)

The nutrient scare is an attempt to put a negative "spin" on an enormous benefit of eCO2: that it improves crop yields.

Faster-growing, more productive crops require more nutrients per acre, though not more nutrients per unit of output. Inadequate nitrogen fertilization reduces protein production relative to carbohydrate production, because proteins contain nitrogen and carbohydrates don't. Likewise, low levels of iron or zinc in soils will result in lower levels of those minerals in some crops. These facts are well-known, and unremarkable.

So, it is possible, by flouting well-established best agricultural practices, to contrive circumstances under which eCO2, or any other factor that improves crop yields, reduces levels of protein or micronutrients in crops.

Farmers know that the more productive crops are, the more nutrients they need, and competent farmers fertilize accordingly. (Or, for nitrogen, they may plant nitrogen-fixing legumes — which, fortunately, benefit greatly from extra CO2.)

If you don’t fertilize according to the needs of your crops, the negative consequences may include reductions in protein and/or micronutrient levels in the resulting crops. The cause of such reductions is not higher CO2 levels, the cause is poor agricultural practices.

Dr. Myers and mathematician Irakli Loladze are the two most prominent promoters of the nutrition scare, and Dr. Loladze admitted to me that food grown in greenhouses with dramatically elevated CO2 levels is as nutritious as food grown outdoors at low CO2 levels, because adequate fertilization mitigates the potential problem.

The most important part of this sentence is the caveat: “after the gas reaches a certain level”.

Do you wonder what that “certain level” is?

Either Dr. Moore didn’t tell the journalist, or Dr. Moore told her but she omitted it from the article.

The answer is that, for most plants, it’s well over 1200 ppmv. Commercial greenhouses often use CO2 generators to keep daytime CO2 levels around 1500 ppmv, because it makes the plants much healthier, faster-growing, and more productive.

Compare that to outdoor levels, which currently average only about 411 ppmv, and will probably never exceed 700 ppmv.

In other words, the “saturation” effect, beyond which the benefits of extra CO2 diminish, is utterly irrelevant except in greenhouses, because it is far, far above what we can ever hope to see outdoors.

Most studies find much larger benefits that that, even with adequate water.

Under dry conditions the benefits of eCO2 are even more dramatic.

This is nonsense. Manmade climate change is not worsening droughts, or other stressors of crops. Instead, higher CO2 levels are mitigating damage from such stressors, by improving plant resilience to them.

The result is a measurable "greening" of the Earth, especially in arid regions.

This is misleading, because it is only true for some crops, and only if they are grown without adequate fertilization, which most farmers know better than to do.

What's more, it is entirely untrue for legumes, like beans, peas, clover, and alfalfa, because those crops fix their own nitrogen, from the air. Either Dr. Norby didn’t know that, or else the reporter misquoted him.

This is misleading, because most of the research in this field has been conducted, not “in labs,” but outdoors, using OTC (open-top container—best!) and FACE (Free Air CO2 Enrichment) methodologies. What's more, many of the thousands of studies of plant response to eCO2 have studied it in combination with a wide variety of other factors.

The results are unambiguous: only in unusual, contrived circumstances is eCO2 not beneficial. In the real world, eCO2 is highly beneficial for most plants under most circumstances.

I am sure that Dr. Norby knows these things. I can only guess at how they came to be omitted from the article.

The reporter who wrote this article did not actually “ask the experts.”

The experts on this topic are agronomists. They’ve conducted thousands of studies of the effects of varying CO2 levels on crops. Many of those studies also tested the effects of other changes, such as temperature, moisture & nutrient levels.

But this journalist didn’t consult any agronomists. The experts she interviewed are expert mostly in other fields.

There are no plausible negative effects on crops from manmade climate change which are comparable in magnitude to the large benefits of higher CO2 levels.

Elevated CO2 (eCO2) does have a warming effect, but the modest warming occurs disproportionately at chilly high latitudes), where it is clearly beneficial, rather than harmful.

Moreover, even where it isn't beneficial, the expected warming, of at most 1 to 2°C compared to current temperatures, will be easily compensated for by farmers, for most crops, by simply adjusting planting dates by a few days:

It is well-known that eCO2 increases yields for all major crops, but that's not the only benefit. eCO2 also reduces damage from droughts, by making crops more water-efficient and drought-resistant. That makes eCO2 especially valuable for mitigating drought-driven famine.

That is a very, very big deal. Throughout human history, famine has been one of the great scourges of mankind, the "third horsemen of the apocalypse," comparable to war and disease.

An estimated 3.7% of world population died in the global drought & famine of 1876-78. Compare that to the 2.7% of world population who died in WWII, and the 2.0% who died in 1918 flu pandemic, and you can understand how devastating famines used to be.

But famines are rare, now, and eCO2 is one of the reasons.

"Science Publishing Group," which published the International Journal of Atmospheric and Oceanic Sciences, is a known predatory publisher, not a respectable source.