Combined with the projected phenological change of pest insects surely this is not the “very good thing” that is being touted here?

http://news.illinois.edu/news/08/0325plantdefense.html

Mary Hinge (06:14:26) : Increased CO2 can only increase plant growth if the plant has extra water, nitrogen and trace elements to support this extra growth. Availability of water throughout the growing season seems to be a problem in many parts of the world.

I can only assume that you are unaware of the studies that showed increased plant growth with higher CO2 despite no increase in water. The plants are more efficient in water use with more CO2. More CO2 mitigates drought issues for plants.

Many sources of nitrogen fixation exist, including plants that fix their own nitrogen. A red herring. Ditto trace elements. Yes, each individual soil may have some element that becomes rate limiting. So what. Most soils most of the time are not rate limited on trace minerals. If you have a problem, add some volcano dust… Trace is just another red herring.

This, IMHO, is clear evidence that most life on this planet evolved to expect 1000ppm+ and has had it for most of evolutionary history (and would want it again…)

If this was the case why is the recent era (shortly before the presence of Homo sapiens) the most biologically diverse the earth has ever been?

A rather bald assertion with nothing to back it up. That’s just a large rat hole to go explore. Does diversity matter? How to determine ‘diversity’? Does the precambrian variety of major body plans outweigh the minor species variations of today? How well does the fossil record record soft bodied critters? What was the impact of the development of sex on the rate of species creation? What is the impact of entering an interglacial on species diversity?

All very interesting questions, and all very irrelevant to this blog. So no, I will not indulge in Rat Chasing; down rat holes or otherwise.

If plants were fully satisfied with their CO2 needs at 200 ppm it would not be rate limiting. If they had had time to fully evolve toward a 200 ppm norm, they would not be rate limited on CO2. The development of C4 metabolism seems to be a partial step in that direction, so plants have been stressed ‘for a while’, but most are still C3 and even C4 is not fully adaptive.

Yes, there is an atmospheric environmental stress on plants, but that stress is too low a CO2 level; as the plants themselves testify by their growth.

BTW, if you are really interested in the problems of drought, perhaps you ought to switch ‘sides’. Drought increases dramatically during ice ages because cold air holds less water than warm air. Warmer air will bring more rains, not less. (Which, unfortunately, is why during this current couple of year cold spell California is having one heck of a drought. Though for the last week my accidental ‘prayer to the rain Gods’ has resulted in some much needed rain…)

Pessimums with poor crop growth are cold. Optimums with good plant growth are warm. Fact of history. Fact of life.

The simple fact is that plants want and need more CO2 to work at full efficiency including the efficiency with which they use water. This holds up to about 1000 to 2000 ppm CO2. That is not an accident, that is the result of directed design via evolution. It’s not gonna change ’cause you don’t like it.

That, to me, is the strongest possible argument that added CO2 is a very good thing…

You might want to take another look.

The problems are not so much the quantity of rain globally but where it does or does not fall. Increased rainfall in areas not accustomed to this as well as decreased rainfall in areas used to it WILL cause problems in food producing regions.

Can you say ‘existence proof’?

We don’t need to speculate about this with ‘ifs’. Nature has already run the experiment. Look at the Roman Optimum, the Medieval Optimum, heck, all the Optimums. During times of increased warmth, the world gets increased crop production.

Now look at all the Pessimums. Migration Era Pessimum, Iron Age Cold Epoch. etc. When the climate turns cold, crops fail and production falls. Social chaos follows.

The notion that we are doomed via crop failure if we warm up is, er, unhinged…

Rather than rant about it I offer one of the best soy debunk sites;
http://www.soyonlineservice.co.nz/

First, I have to correct my statement quoted above: That ought to have been 30% oil and 50% protein.

Terry, I agree with the things on that site! But ruminants are not humans!

I’m quite happy to feed soy meal to chickens and soy oil to my car. But don’t you dare try to feed me a soy burger! Soy has many ‘issues’ as a human food and ought to be consumed in quantities of no more than a couple of grams a day (and most of that processed like soy sauce to remove the ‘bad stuff’!)

So I think we are ‘in violent agreement’ on soy as human food…

BTW, most foods have some toxic issues to deal with. Red Kidney beans will make you very sick or even kill you if not cooked at boiling (learned each year around christmas with new slow cookers and old chili recipes… ) Onions are lethal to many animals (dogs, cats) by hemolysis, but not to humans (why? don’t ask why…). Green potato skins (and the potato under them) have solanine toxin in them. Rhubarb leaves, parsnip tops, etc.

Plants don’t really want to be eaten!

So the ‘problems’ with soy are not unique. And the solutions are largely the same. Eat less than a toxic dose. Find a process that removes the toxin (boil kidney beans, chop rhubarb leaves off the stems). Feed the plant to an animal that can eat it, then eat the animal (acorns to goats). Eat only the non-toxic parts (parsnip roots are great, but wear a chem suit when harvesting, the tops give rashes…)

Because of this I see no reason to ‘ban’ soy beans; just use them wisely like all the other ‘toxic’ plants we depend on… That a whole industry is thriving on doing exactly the opposite,… well, yes, you are right, and they ought to stop it.

http://en.wikipedia.org/wiki/Allelopathy

Plants make a bunch of ‘chemical weapons’ to kill off intruder species. That’s why the lawn dies under the walnut tree. There is a whole art to ‘companion planting’ to find which plants ignore each others attacks… (Be careful where you plant sunflowers… and don’t plant peas and onions together..)

However, there are still lots and lots of genetic code, expressed as traits or long silenced, that are just there, and continue on, riding on the coattails of genes nearby that improve species survival in the current environment. Gene coding is a chaotic system for most of it, and a selective process for some of it.

Absolutely! My favorite example of this is the experiments that have shown birds still have the genes for teeth. They are just back in the ‘tool chest’ portion and not in the ‘active’ portion…

Transplant ‘gum’ tissue to a different part of the bird embryo and it makes teeth…

I can only assume that you are unaware of the studies that showed increased plant growth with higher CO2 despite no increase in water. The plants are more efficient in water use with more CO2. More CO2 mitigates drought issues for plants.

Many sources of nitrogen fixation exist, including plants that fix their own nitrogen. A red herring. Ditto trace elements. Yes, each individual soil may have some element that becomes rate limiting. So what. Most soils most of the time are not rate limited on trace minerals. If you have a problem, add some volcano dust… Trace is just another red herring.

This, IMHO, is clear evidence that most life on this planet evolved to expect 1000ppm+ and has had it for most of evolutionary history (and would want it again…)

If this was the case why is the recent era (shortly before the presence of Homo sapiens) the most biologically diverse the earth has ever been?

You might want to take another look.

Jeff Alberts (12:19:57) :
Has happened before, will happen again, regardless of whether humans even exist.

The big problems occur when these rapid changing events happen when over 6,000,000,000 people live on the planet.

Mary Hinge (11:26:24) :

The problems are not so much the quantity of rain globally but where it does or does not fall. Increased rainfall in areas not accustomed to this as well as decreased rainfall in areas used to it WILL cause problems in food producing regions. You seem to think that rainfall is pretty evenly distributed?

Has happened before, will happen again, regardless of whether humans even exist.

Smokey (09:32:37) :
OK, try this ‘if’ on for size:
If the planet warms, evaporation increases.
If evaporation increases, precipitation [rain] increases.
If rain increases, droughts decrease.

The problems are not so much the quantity of rain globally but where it does or does not fall. Increased rainfall in areas not accustomed to this as well as decreased rainfall in areas used to it WILL cause problems in food producing regions. You seem to think that rainfall is pretty evenly distributed?

If the planet warms, evaporation increases.

If evaporation increases, precipitation [rain] increases.

If rain increases, droughts decrease.

Unless, of course, down is up, black is white, evil is good, a warmer climate decreases evaporation, and global warming causes global cooling.

Smokey (06:11:15) :
It appears that your belief is that AGW will cause more droughts everywhere, and will cause droughts which will negate any benefits from increased atmospheric CO2.

My actual belief in itself won’t cause an increased probability of droughts in many prime agricultural areas, but the effects of AGW will.

Since the amount of rainfall is more or less constant globally, that particular scare tactic fails. If one area experiences drought conditions, then another marginal area will get additional rainfall, which will result in better growing conditions in that area if CO2 is abundant.

Sorry Smokey but that is a ridiculous statement. If agricultural areas experience drought conditions then that certainly reduces any benefits of additional CO2, especially if the marginal areas consist of mountains, forest or oceans. A small change in rainfall in some areas will undoubtally have major effects either regionally or even globally.

What will it take for you to understand that “climate change” is composed of changing local weather patterns around the globe? An epiphany?

Errr, of course climate change is composed of changing local weather patterns, that’s why it’s called ‘change’. The important factor is the rate of change and how fast we and the rest of life on Earth can adapt to this.

At some point the scales will fall from your eyes. If not, everyone will realize that your beliefs are based on a politically based AGW agenda, rather than on a desire to understand the true reason for global warming, which is a natural result of the planet’s emergence from the last Ice Age.

I do not belong to any political party not do I have any interest in the politics of global warming discussions. I care about this planet and the people and life that inhabits it. It is obvious to anyone that reads the literature and other data we have available that there are major climatic changes happening, it is also obvious that your own theory is flawed in that you haven’t described a particular method nor an explanation for the very rapid rise in the last 100 years.

Maybe I’m the crazy one,

At last a grain of truth from you ;-)

….but I think there is hope for you. If rising CO2 levels do not result in rising global temperatures, and if CO2 triggers plant growth, then the conclusion is obvious to even the most casual observer: higher levels of CO2 are beneficial to life. Therefore demonizing CO2 is anti-life.

Lots of ‘ifs’ in that statement. CO2 will/has result(ed) in an increase in global temperatures, try that scale remover yourself!

Increased CO2 can only increase plant growth if the plant has extra water, nitrogen and trace elements to support this extra growth. Availability of water throughout the growing season seems to be a problem in many parts of the world. Rapid climate shifts and increasing temperature extremes as predicted by AGW would increase this problem and more than negate any benifits of extra co2.

It appears that your belief is that AGW will cause more droughts everywhere, and will cause droughts which will negate any benefits from increased atmospheric CO2.

Since the amount of rainfall is more or less constant globally, that particular scare tactic fails. If one area experiences drought conditions, then another marginal area will get additional rainfall, which will result in better growing conditions in that area if CO2 is abundant.

What will it take for you to understand that “climate change” is composed of changing local weather patterns around the globe? An epiphany?

At some point the scales will fall from your eyes. If not, everyone will realize that your beliefs are based on a politically based AGW agenda, rather than on a desire to understand the true reason for global warming, which is a natural result of the planet’s emergence from the last Ice Age.

Maybe I’m the crazy one, but I think there is hope for you. If rising CO2 levels do not result in rising global temperatures, and if CO2 triggers plant growth, then the conclusion is obvious to even the most casual observer: higher levels of CO2 are beneficial to life. Therefore demonizing CO2 is anti-life.

Syl (15:52:35) :
You missed the point that it is not necessary to wait for evolutionary changes for plants to adapt. It’s already built in. As is the ability for humans to choose what to plant where and when.

You, I and every member of the human race has the genes for a prehensile tail ‘built in’. It does’t mean that it will switch on readily (which is good news for tailors)! The ‘switches’ that turn on or off the genes have also evolved so that the organism is adapted to the current conditions. Like the genes for the tail, these will not switch on or off readily so it becomes immaterial that the genes ‘built in’ arestill around somewhere. The plants that were around during the higher CO2 levels of the early Carboniferous are very different to the plants alive today (with the usual odd exception that always happens with biology!)