Higher CO2 levels may be good for plants: German scientists

[Roon]

The dangerous rise in greenhouse gases in the atmosphere may be troubling scientists and world leaders but it could prove to be a boon for plants, German researchers said Tuesday.
Increasing exposure to carbon dioxide appears to boost crop yields, Hans-Joachim Weigel of the Johann Heinrich von Thuenen Institute for rural areas, forestry and fisheries in the central city of Brunswick told AFP.

"Output increased by about 10 percent for barley, beets and wheat" when the plants were subjected to higher levels of carbon dioxide, Weigel said
http://www.breitbart.com/article.php?id=080708124018.8nen8ib9&show_article=1

[Buzz Clik]

1. That's old news though perhaps not to these scientists. There's a catch:

High CO₂ accompanied by elevated temperatures is not good for plants.

There's no silver lining.

[tridim]

2. Actually high CO2 concentrations allow plants to survive higher temperatures.

Just ask any semi-serious indoor gardener.

Of course this isn't an excuse to belch out even more C02 into the atmosphere.

[Buzz Clik]

7. Let's look at this more carefully:

Certain plants will handle increased temperatures (and the unavoidable early onset of drought) when CO₂ increases, others do poorly. It's a reflection of their plant physiology -- the C-3 plants will not do well but C-4 plants will be less affected:

Comparative responses of model C3 and C4 plants to drought in low and elevated CO2

Abstract:

Summary

Interactive effects of CO2 and water availability have been predicted to alter the competitive relationships between C3 and C4 species over geological and contemporary time scales. We tested the effects of drought and CO2 partial pressures (pCO2) ranging from values of the Pleistocene to those predicted for the future on the physiology and growth of model C3 and C4 species. We grew co-occurring Abutilon theophrasti (C3) and Amaranthus retroflexus (C4) in monoculture at 18 (Pleistocene), 27 (preindustrial), 35 (current), and 70 (future) Pa CO2 under conditions of high light and nutrient availability. After 27 days of growth, water was withheld from randomly chosen plants of each species until visible wilting occurred. Under well-watered conditions, low pCO2 that occurred during the Pleistocene was highly limiting to C3 photosynthesis and growth, and C3 plants showed increased photosynthesis and growth with increasing pCO2 between the Pleistocene and future CO2 values. Well-watered C4 plants exhibited increased photosynthesis in response to increasing pCO2, but total mass and leaf area were unaffected by pCO2. In response to drought, C3 plants dropped a large amount of leaf area and maintained relatively high leaf water potential in remaining leaves, whereas C4 plants retained greater leaf area, but at a lower leaf water potential. Furthermore, drought-treated C3 plants grown at 18 Pa CO2 retained relatively greater leaf area than C3 plants grown at higher pCO2 and exhibited a delay in the reduction of stomatal conductance that may have occurred in response to severe carbon limitations. The C4 plants grown at 70 Pa CO2 showed lower relative reductions in net photosynthesis by the end of the drought compared to plants at lower pCO2, indicating that CO2 enrichment may alleviate drought effects in C4 plants. At the Pleistocene pCO2, C3 and C4 plants showed similar relative recovery from drought for leaf area and biomass production, whereas C4 plants showed higher recovery than C3 plants at current and elevated pCO2. Based on these model systems, we conclude that C3 species may not have been at a disadvantage relative to C4 species in response to low CO2 and severe drought during the Pleistocene. Furthermore, C4 species may have an advantage over C3 species in response to increasing atmospheric CO2 and more frequent and severe droughts.

So, if you're willing to subsist mostly on C-4 plants (mostly warm season grasses such as corn), then you'll be all set.

[jdlh8894]

3. Plants thrive (wait for it)

in GREENHOUSES!!!

[Buzz Clik]

4. How often do you water your plants in the greenhouse?

More often than natural rainfall.

[jdlh8894]

6. Actually, less

Humidity works wonders.

[Buzz Clik]

8. Less? You water less at the elevated temperatures in a greenhouse than in the garden?

okey doke.

(none of this makes sense)

[Brotherjohn]

10. Yes, they have some protection from cold, and a more constant environment (warmth and humidity).

So let's crank the earth's thermostat up!! Maybe we'll "thrive" too!

The greenhouse effect wasn't called that b/c CO2 in greenhouses is what makes plants thrive. It was called that because CO2 in the atmosphere has the same effect as the greenhouse itself... the semitransparent walls, holding in heat.

[Brotherjohn]

11. Most CO2 causing the greenhouse effect is in the upper atmosphere...

... and not available to the biosphere. And even if it were, there is FAR too much CO2 in the atmosphere already for all of the earth's plant life to somehow "remediate" the situation... and it's increasing at an unprecedented rate on geologic timescales. Every forest in the world could grow like gangbusters, and all the phytoplankton in the sea could bloom, and we'd still have rising CO2, and rising temperatures. And then what if all those trees die? The CO2 is right back in the atmosphere (it's a cycle you know). Plus, there is evidence that shows trees are already growing at near capacity (i.e. can't use much more CO2 even if it were available to them). These crops grew 10% better? What percentage has atmospheric CO2 increased in the past few decades (hint: it's much greater than 10%).

So the issue of CO2 helping plants is irrelevant.

Great, some crops might do better (if CO2 were the only factor, which it is not). But then sea level is still up 10 feet and temperature is up several degrees, diseases spread on unprecedented scales, fields dry out, people starve, large areas of the earth become uninhabitable.

But hey, the corn's doing great! (when it can get water to go with the abundance of CO2)

[PVnRT]

5. Oh, great, I'm sure the knuckle-draggers around here will be talking about it

"What's the big deal with those hippies? More trees will grow that they can hug."

[Buzz Clik]

9. These studies pop up with some regularity.

And, yes, mega-brains like Limbaugh leap all over them ... and never get to the downside.

[Grinchie]

12. They have also fount that trees grow larger in response to the production of more lignin

Trees grow bigger in higher CO2 environments, sequestering more carbon.

Unfortunately, most tree's tend to break apart since they cannot support the increased mass in their limbs, thus leading to more self cleaning (Branches breaking off due to their own weight).

It can be good or bad, depending on how you look at it. More organic material in the forests, if any are able to recover where they have been destroyed.

Although the plants can adapat to increased CO2 levels, they have a hard time adapting to drought, floods, heat waves, rising sea levels, new insect predators and freak blizzards, which is the main issue we are going to be dealing with in this Global Warming era.

I have seen the world changing before my eye's in my own lifetime, and it looks pretty grim. That's why I work for nobody but myself and my wife. Life is too short to work in a system that is so oblivious to the environment, and pay taxes to those that continue to keep the masses slaves to debt.

At this point, it is clear that there is unlimited low cost energy out there for every man woman and child on earth, and all the others yet to be born, and the suppression of this technology can no longer be kept hidden by the money interests. It is my view that they would rather invoke another Dark Age in order to quash developed knowledge and start another cycle of monarchy and imperialism.

We are at the edge of a perfect storm. Genetic Pollution from GMO is destroying the diversity, and creating new issues regarding health and the evolution of life on this planet. Bee's are dying, and they still refuse to test if it is horizontal gene transfer from BT GMO Food crops. We are nothing but the civilization that came after the Dinosaurs that squandered the planet for a buck.

Save your books! You may not have computers in a few years. Think how you would learn if you did not have access to the internet.

[seasat]

13. Recent research shows that weeds outperform crops

While CO2 enrichment can support increased plant growth, the plants have to be able to adapt to the changes in temperature, precipitation levels, limiting nutrients, and competition from weeds. Recently it was pointed out in a study (and makes obvious sense) is that weeds can adapt to the climate changes and prosper while our crops may not be able to compete with them. We've bred our crops for specific qualities areas while weeds are opportunistic. One of the solutions proposed is to try and hybridize our crops with some of the favorable characteristics of these weeds.

[devilgrrl]

14. Are these the same guys that claim Toxic Sludge is good for you?

Sounds like it.

[wishlist]

15. Poison ivy and undesirable pests thrive with global warming too n/t