CO2 is good for agriculture

[Misha & Ira 113]

Agriculture (Species -- Wheat: CO2 vs. Stress of Drought) -- Summary

Atmospheric CO2 enrichment typically enhances photosynthesis and biomass production in wheat plants under normal growing conditions (see, for example, our Subject Index Summaries pertaining to Agriculture (Species - Wheat: Photosynthesis and Biomass). But what happens when environmental conditions are less than ideal? In this brief recapitulation of the results of studies for which we have produced Journal Reviews, we report on what has been learned when lack of water limits the growth of wheat.

In a study of the ecosys crop growth model, Grant et al. (1999) compared their model calculations of wheat biomass production in response to elevated CO2 at high and low soil moisture contents with observed values measured in a FACE experiment conducted on spring wheat grown at atmospheric CO2 concentrations of 350 and 500 ppm near Maricopa, Arizona, USA. They report that in that very realistic experimental study, the observed CO2-induced percentage increases in biomass were determined to be 10% in the high soil moisture regime but 18% in the low soil moisture regime.

In a subsequent FACE study conducted at the same location, Li et al. (2000) grew wheat plants at close to the same CO2 concentrations (370 and 550 ppm) under well-watered conditions and a water-stressed regime where the plants received only 50% as much irrigation water as the well-watered plants; and in this case, much as in the prior study, the CO2-enriched well-watered plants exhibited a grain weight increase of 14%, while the CO2-enriched water-stressed plants experienced a grain weight increase of 24%. At the same time, in an ancillary study of the same wheat crop, Wall (2001) observed that as the amount of moisture in the soil decreased, leaf water potentials of the CO2-enriched plants were always higher (less negative) than those of the ambiently-grown plants, as a consequence of CO2-induced improvements in both drought avoidance and drought tolerance. In fact, during the driest part of this two-year study, the CO2-enriched plants in the "dry" irrigation treatment exhibited leaf water potentials that were similar to those measured on ambiently-grown plants in the "wet" irrigation treatment. Thus, the extra 180 ppm CO2 of this study completely ameliorated the effects of water-stress in these plants under the driest conditions they encountered, as inferred by leaf water potential data. Also of interest in this regard, the study of Lin and Wang (2002) suggests that elevated levels of atmospheric CO2 may well have a greater impact on increasing drought resistance in inherently less-drought-tolerant species than they do in more-drought-tolerant species, which is to say that atmospheric CO2 enrichment may help those plants most that need help most.

Other researchers have obtained similar results. Schutz and Fangmeier (2001), for example, grew spring wheat for an entire season under well-watered and water-stressed conditions in pots located within open-top chambers maintained at atmospheric CO2 concentrations of 367 and 650 ppm, finding that the elevated CO2 stimulated yield by 40% in the well-watered treatment but by 57% in the water-stressed treatment. In like manner, Dong-Xiu et al. (2002) grew spring wheat in open-top chambers maintained at atmospheric CO2 concentrations of 350 and 700 ppm and soil moisture contents of 40 and 80% field capacity, finding that the extra CO2 of their study increased net photosynthesis by 48% in the high soil water treatment but by 97% in the low soil water treatment.

Based on results such as those described above that have been obtained from many real-world experimental studies, Reyenga et al. (2001) ran a cropping system model designed to reveal how predicted climate changes might impact wheat production in the southern part of Australia with an atmospheric CO2 concentration of 700 ppm in combination with several computer-generated scenarios of warmer temperature and reduced rainfall. They found that under most climate change scenarios, cropping range expanded northward due to the "carbon dioxide fertilization effect." In addition, the elevated CO2 increased yields by 13 to 52%, with the greater responses occurring in the drier climates.

In light of these several observations, it is clear that the ongoing rise in the air's CO2 content should have its greatest relative impact on the growth and development of wheat where a lack of sufficient soil moisture currently reduces grain yields below their genetic potential. As a result, people around the world who are forced to farm marginal lands beset by water shortages should most benefit, relatively speaking, from this phenomenon.

References

Dong-Xiu, W., Gen-Xuan, W., Yong-Fei, B., Jian-Xiong, L. and Hong-Xu, R. 2002. Response of growth and water use efficiency of spring wheat to whole season CO2 enrichment and drought. Acta Botanica Sinica 44: 1477-1483.

Grant, R.F., Wall, G.W., Kimball, B.A., Frumau, K.F.A., Pinter Jr., P.J., Hunsaker, D.J. and Lamorte, R.L. 1999. Crop water relations under different CO2 and irrigation: testing of ecosys with the free air CO2 enrichment (FACE) experiment. Agricultural and Forest Meteorology 95: 27-51.

Li, A.-G., Hou, Y.-S., Wall, G.W., Trent, A., Kimball, B.A. and Pinter Jr., P.J. 2000. Free-air CO2 enrichment and drought stress effects on grain filling rate and duration in spring wheat. Crop Science 40: 1263-1270.

Lin, J.-S and Wang, G.-X. 2002. Doubled CO2 could improve the drought tolerance better in sensitive cultivars than in tolerant cultivars in spring wheat. Plant Science 163: 627-637.

Reyenga, P.J., Howden, S.M., Meinke, H. and Hall, W.B. 2001. Global change impacts on wheat production along an environmental gradient in south Australia. Environmental International 27: 195-200.

Schutz, M. and Fangmeier, A. 2001. Growth and yield responses of spring wheat (Triticum aestivum L. cv. Minaret) to elevated CO2 and water limitation. Environmental Pollution 114: 187-194.

Wall, G.W. 2001. Elevated atmospheric CO2 alleviates drought stress in wheat. Agriculture, Ecosystems and Environment 87: 261-271.

http://www.co2science.org/subject/a/summaries/agwheatdrought.php

[one...two...tree 2,762]

Climate myths: Higher CO₂ levels will boost plant growth and food production

According to some accounts, the rise in carbon dioxide will usher in a new golden age where food production will be higher than ever before and most plants and animals will thrive as never before. If it sounds too good to be true, that's because it is.

CO₂ is the source of the carbon that plants turn into organic compounds, and it is well established that higher CO₂ levels can have a fertilising effect on many plants, boosting growth by as much as a third.

However, some plants already have mechanisms for concentrating CO₂ in their tissues, known as C₄ photosynthesis, so higher CO₂ will not boost the growth of C₄ plants.

Where water is a limiting factor, all plants could benefit. Plants lose water through the pores in leaves that let CO₂ enter. Higher CO₂ levels mean they do not need to open these pores as much, reducing water loss.

However, it is extremely difficult to generalise about the overall impact of the fertilisation effect on plant growth. Numerous groups around the world have been conducting experiments in which plots of land are supplied with enhanced CO₂, while comparable nearby plots remain at normal levels.

These experiments suggest that higher CO₂ levels could boost the yields of non-C₄ crops by around 13 per cent.

Limiting factors

However, while experiments on natural ecosystems have also found initial elevations in the rate of plant growth, these have tended to level off within a few years. In most cases this has been found to be the result of some other limiting factor, such as the availability of nitrogen or water.

The regional climate changes that higher CO₂ will bring, and their effect on these limiting factors on plant growth, such as water, also have to be taken into account. These indirect effects are likely to have a much larger impact than CO₂ fertilisation.

For instance, while higher temperatures will boost plant growth in cooler regions, in the tropics they may actually impede growth. A two-decade study of rainforest plots in Panama and Malaysia recently concluded that local temperature rises of more than 1ºC have reduced tree growth by 50 per cent (see Don't count on the trees).

Another complicating factor is ground level ozone due to air pollution, which damages plants. This is expected to rise in many regions over the coming decades and could reduce or even negate the beneficial effects of higher CO₂ (see Climate change warning over food production).

In the oceans, increased CO₂ is causing acidification of water. Recent research has shown that the expected doubling of CO₂ concentrations could inhibit the development of some calcium-shelled organisms, including phytoplankton, which are at the base of a large and complex marine ecosystem (see Ocean acidification: the other CO2 problem). That may also result in significant loss of biodiversity, possibly including important food species.

Levelling off

Some have suggested that the increase in plant growth due to CO₂ will be so great that it soaks up much of the extra CO₂ from the burning of fossil fuels, significantly slowing climate change. But higher plant growth will only lock away CO₂ if there is an accumulation of organic matter.

Studies of past climate changes suggest the land and oceans start releasing more CO₂ than they absorb as the planet warms. The latest IPCC report concludes that the terrestrial biosphere will become a source rather than a sink of carbon before the end of the century.

What's more, even if plant growth does rise overall, the direct and indirect effects of higher CO₂ levels will be disastrous for biodiversity. Between 20 to 30% of plant and animal species face extinction by the end of the century, according to the IPCC report.

As for food crops, the factors are more complex. The crops most widely used in the world for food in many cases depend on particular combinations of soil type, climate, moisture, weather patterns and the infrastructure of equipment, experience and distribution systems. If the climate warms so much that crops no longer thrive in their traditional settings, farming of some crops may be able to shift to adjacent areas, but others may not. Rich farmers and countries will be able to adapt more easily than poorer ones.

Predicting the world's overall changes in food production in response to elevated CO₂ is virtually impossible. Global production is expected to rise until the increase in local average temperatures exceeds 3°C, but then start to fall. In tropical and dry regions increases of just 1 to 2°C are expected to lead to falls in production. In marginal lands where water is the greatest constraint, which includes much of the developing world but also regions such as the western US, the losses may greatly exceed the gains.

http://www.newscient...production.html

Edited December 7, 2011 by Mister Fancypants

[Hilarious Clinton 452]

[one...two...tree 2,762]

[Misha & Ira 113]

Climate myths: Higher CO₂ levels will boost plant growth and food production

According to some accounts, the rise in carbon dioxide will usher in a new golden age where food production will be higher than ever before and most plants and animals will thrive as never before. If it sounds too good to be true, that's because it is.

CO₂ is the source of the carbon that plants turn into organic compounds, and it is well established that higher CO₂ levels can have a fertilising effect on many plants, boosting growth by as much as a third.

However, some plants already have mechanisms for concentrating CO₂ in their tissues, known as C₄ photosynthesis, so higher CO₂ will not boost the growth of C₄ plants.

Where water is a limiting factor, all plants could benefit. Plants lose water through the pores in leaves that let CO₂ enter. Higher CO₂ levels mean they do not need to open these pores as much, reducing water loss.

However, it is extremely difficult to generalise about the overall impact of the fertilisation effect on plant growth. Numerous groups around the world have been conducting experiments in which plots of land are supplied with enhanced CO₂, while comparable nearby plots remain at normal levels.

These experiments suggest that higher CO₂ levels could boost the yields of non-C₄ crops by around 13 per cent.

Limiting factors

However, while experiments on natural ecosystems have also found initial elevations in the rate of plant growth, these have tended to level off within a few years. In most cases this has been found to be the result of some other limiting factor, such as the availability of nitrogen or water.

The regional climate changes that higher CO₂ will bring, and their effect on these limiting factors on plant growth, such as water, also have to be taken into account. These indirect effects are likely to have a much larger impact than CO₂ fertilisation.

For instance, while higher temperatures will boost plant growth in cooler regions, in the tropics they may actually impede growth. A two-decade study of rainforest plots in Panama and Malaysia recently concluded that local temperature rises of more than 1ºC have reduced tree growth by 50 per cent (see Don't count on the trees).

Another complicating factor is ground level ozone due to air pollution, which damages plants. This is expected to rise in many regions over the coming decades and could reduce or even negate the beneficial effects of higher CO₂ (see Climate change warning over food production).

In the oceans, increased CO₂ is causing acidification of water. Recent research has shown that the expected doubling of CO₂ concentrations could inhibit the development of some calcium-shelled organisms, including phytoplankton, which are at the base of a large and complex marine ecosystem (see Ocean acidification: the other CO2 problem). That may also result in significant loss of biodiversity, possibly including important food species.

Levelling off

Some have suggested that the increase in plant growth due to CO₂ will be so great that it soaks up much of the extra CO₂ from the burning of fossil fuels, significantly slowing climate change. But higher plant growth will only lock away CO₂ if there is an accumulation of organic matter.

Studies of past climate changes suggest the land and oceans start releasing more CO₂ than they absorb as the planet warms. The latest IPCC report concludes that the terrestrial biosphere will become a source rather than a sink of carbon before the end of the century.

What's more, even if plant growth does rise overall, the direct and indirect effects of higher CO₂ levels will be disastrous for biodiversity. Between 20 to 30% of plant and animal species face extinction by the end of the century, according to the IPCC report.

As for food crops, the factors are more complex. The crops most widely used in the world for food in many cases depend on particular combinations of soil type, climate, moisture, weather patterns and the infrastructure of equipment, experience and distribution systems. If the climate warms so much that crops no longer thrive in their traditional settings, farming of some crops may be able to shift to adjacent areas, but others may not. Rich farmers and countries will be able to adapt more easily than poorer ones.

Predicting the world's overall changes in food production in response to elevated CO₂ is virtually impossible. Global production is expected to rise until the increase in local average temperatures exceeds 3°C, but then start to fall. In tropical and dry regions increases of just 1 to 2°C are expected to lead to falls in production. In marginal lands where water is the greatest constraint, which includes much of the developing world but also regions such as the western US, the losses may greatly exceed the gains.

http://www.newscient...production.html

The problems with your article are too many to list.....overall it is vague and speculative. It lacks an understanding of how the carbon cycle works and makes claims while on the surface may be true, adding CO2 to the ocean will acidify it, but fails to mention that as the ocean warms it tends to release it rather than sinking it. This is the main problem with all the man-made warming babble...it uses true facts to lie. The author would have you believe that warm oceans will become acidic.

You post global warming for dummies...the real reason we are warming is that we are coming out of an ice age...as the planet warms, CO2 is expected to be released from the oceans into the atmosphere...

The last sentence of the article is actually the truth...

[slim 1,530]

Gosh, it's almost as if this is a natural process the earth goes through on a pretty regular basis.

[Ban Hammer 13,508]

Gosh, it's almost as if this is a natural process the earth goes through on a pretty regular basis.

surviving liberal causes?

[slim 1,530]

surviving liberal causes?

What's funny is even in a man-made disaster the liberals go to the conservatives for help.

[one...two...tree 2,762]

The last sentence of the article is actually the truth...

This is the last sentence:

Global production is expected to rise until the increase in local average temperatures exceeds 3°C, but then start to fall. In tropical and dry regions increases of just 1 to 2°C are expected to lead to falls in production. In marginal lands where water is the greatest constraint, which includes much of the developing world but also regions such as the western US, the losses may greatly exceed the gains.

But wait, I thought you said Global Warming was made up? A left-wing concoction?

So, are you now conceding that GW is real and is happening? And to be clear, GW - meaning accelerated warming of the planet due to CO2 emissions.

[Misha & Ira 113]

No...I meant the first sentence of the last paragraph. My mistake.

By the way...in your sentence, do you notice the word 'may'? Almost anything may happen...including you stopping to believe foolishness...but that does not mean 'will'.

[one...two...tree 2,762]

No...I meant the first sentence of the last paragraph. My mistake.

By the way...in your sentence, do you notice the word 'may'? Almost anything may happen...including you stopping to believe foolishness...but that does not mean 'will'.

So you think it's foolish to accept the world-wide consensus* among the bodies of science who study the climate that CO2 emissions are adding enormous amounts of CO2 into the atmosphere, which the world's normal Carbon Cycle cannot simple get rid of, but think it's more logical to believe whatever bunk you've bought into by fringe groups? Where's the rationale in that? The only way you could make peace with such a position is to believe it's all a conspiracy, which has absolutely no logic or rationale to it.

*The scientific consensus is clearly expressed in the reports of the Intergovernmental Panel on Climate Change (IPCC). Created in 1988 by the World Meteorological Organization and the United Nations Environmental Programme, IPCC's purpose is to evaluate the state of climate science as a basis for informed policy action, primarily on the basis of peer-reviewed and published scientific literature (3). In its most recent assessment, IPCC states unequivocally that the consensus of scientific opinion is that Earth's climate is being affected by human activities: “Human activities … are modifying the concentration of atmospheric constituents … that absorb or scatter radiant energy. … [M]ost of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations” [p. 21 in (4)].

IPCC is not alone in its conclusions. In recent years, all major scientific bodies in the United States whose members' expertise bears directly on the matter have issued similar statements.

http://www.sciencemag.org/content/306/5702/1686.full

....

Once you realize just how far out denialism of the science of GW is, you'll see just how far you must take it to insist that the experts are wrong and you are magically correct.

[Misha & Ira 113]

So you think it's foolish to accept the world-wide consensus* among the bodies of science who study the climate that CO2 emissions are adding enormous amounts of CO2 into the atmosphere, which the world's normal Carbon Cycle cannot simple get rid of, but think it's more logical to believe whatever bunk you've bought into by fringe groups? Where's the rationale in that? The only way you could make peace with such a position is to believe it's all a conspiracy, which has absolutely no logic or rationale to it.

http://www.sciencemag.org/content/306/5702/1686.full

....

Once you realize just how far out denialism of the science of GW is, you'll see just how far you must take it to insist that the experts are wrong and you are magically correct.

I think you fail to realize that all this carbon was once in the carbon cycle to begin with...it has only been sequestered. All this carbon was once running around or being eaten at one point.

There was once a scientific that the earth was flat...if we had lived then....I would be arguing that with you too.

[웃 910]

How come all the climate change deniers are Republican?

The site has to be the biggest joke I've seen this year. The silver quality apple award, what a fvcking joke!

Number 8 out of 12 of the climate change denial list of bozos:

No. 8: Center for the Study of Carbon Dioxide and Global Change (A.K.A. The Idso Family)

The Idso clan is the von Trapp family of climate change denial. In 1980, paterfamilias Sherwood Idso, a self-described "bio-climatologist," published a paper in Science concluding that doubling the world's carbon dioxide concentration wouldn't change the planet's temperature all that much. In years that followed, Idso and his colleagues at Arizona State University's Office of Climatology received more than $1 million in research funding from oil, coal, and utility interests. In 1990, he coauthored a paper funded by a coal mining company, titled "Greenhouse Cooling."

In 1998, Idso's son Craig founded the Center for the Study of Carbon Dioxide and Global Change and began publishing CO₂ Science, an online digest of climate change skepticism. He subsequently earned his PhD in geography from ASU under the tutelage of climate skeptic Robert Balling, then the director of its climatology program. In the early 2000s, Idso was director of environmental science at Peabody Energy, the world's largest privately owned coal company. After Peabody laid him off, he began aggressively fundraising for the center, whose budget increased from just north of $30,000 in 2004 to more than $1 million last year. Since 2006, the center has mounted a spirited defense of carbon dioxide using everything from ancient tree-ring data to elementary-school science experiments. "cience tells us that putting more CO₂ in the air would actually be good for the planet," its website says. "Therefore, in invoking the precautionary principle one last time, our advice to policy makers who may be tempted to embrace Kyoto-type programs is simply this:Don't mess with success!"

Like his dad, Craig Idso has become a preeminent "scientific" climate change naysayer. In lieu of his father, who refuses to travel in airplanes, in June the younger Idso jetted off to the Heartland Institute's climate change conference. There he released "Climate Change Reconsidered," a 20-page report that suggested that Intergovernmental Panel on Climate Change scientists had tweaked their findings in hopes of being invited to conferences involving "hotel accommodations at exotic locations." More recently, the Idsos have marketed the report as a timely expose of "Climategate Culture."

In 1998, Keith Idso, vice president of the Center for the Study of Carbon Dioxide and a school teacher, did an experiment with his fifth-grade science class. The lesson, which demonstrates that plants need CO₂ to thrive, has been taught in other classrooms across Arizona. Sherwood Idso has praised his son's experiment for showing that cutting carbon emissions would reduce "the future benefits we could have in terms of agricultural productivity." In 1999, the speaker of the Arizona House of Representatives appointed Keith Idso to serve on the state's Advisory Council on Environmental Education.

Sherwood Idso says the coal and oil interests that have supported the Center for the Study of Carbon Dioxide have been backing off. Fundraising is "so poor that I'm not earning anything," he says. "Everything has to go to my son [Craig] to help him maintain himself and the five kids that he has now, and so we're just scraping by." But the center's 2008 tax filing shows that it entered 2009 with $445,000 in cash on hand. Last year, it paid Sherwood Idso $50,000, Craig Idso $79,000, and Craig Idso's wife, M. Anne Idso, $52,000. The center also made a $58,000 "scientific research" grant to a group called CO2 Science. Tax records reveal that CO2 Science's $75,000 budget that year mostly went toward paying Craig Idso a $45,000 salary, bringing his and his wife's total take from the family business to $182,000.

Edited December 7, 2011 by Lord Infamous

[one...two...tree 2,762]

I think you fail to realize that all this carbon was once in the carbon cycle to begin with...it has only been sequestered. All this carbon was once running around or being eaten at one point.

Um, no it wasn't. The atmosphere that we now have on Earth is far different than it was a billion years ago. Life as we know it would not exist on this planet without the delicate balance of the Carbon Cycle, which has remained relatively constant for millions of years because there were no sudden, large influxes of CO2 emitted into the atmosphere. Volcanic activity was the biggest contributor prior to the Industrial Revolution and the burning of fossil fuels.

What a lot of denialists fight against is the idea that our ecosystem is fragile. While it is true that planet Earth will go on and exist without us, life as we know it is in serious jeopardy because of human activity in the form of CO2 emissions. The denialists typically have a pro-libertarian viewpoint that we should be free to use our natural resources without any concern about sustainability and that is very ignorant and dangerous viewpoint. Our resources are finite. Our ecosystem is fragile and if we don't take measures towards a more sustainable future, our children's children and their children will be faced with a worldwide ecological disaster.

There was once a scientific that the earth was flat...if we had lived then....I would be arguing that with you too.

Dude, the modern scientific method is light years ahead of what you call 'scientific discovery' of 700 years ago. But lets assume that you still think that somehow all these modern bodies of science who study climate are simply wrong. So, we can send a satellite that studies the moons of Saturn with pinpoint accuracy, but somehow, we can't see a cause and effect relationship between CO2 emissions and the earth's temperature?

Seriously, you need to step back and realize just how farcical it is to insist the science on GW is wrong or a lie. At some point, logic hits you on the head, or leave all logic and rationale out the window.

[luckytxn 2,265]

There has never been a scientific study that CO2 is causing an acceleration of Global change that hasn't been shown to be wrong by others. This is ignored by the very people that want to believe that man is destructive to our global environment. CO2 emissions have actually been pretty stable. Here is what 300 PPM's is if done.

The CO2 was 4.0 percent a hundred years ago. If there really were a 300 PPM increase in the last hundred years then the percent of CO2 is still 4.0 percent. Now if the GW morons really wanted to scare sheep then they should have stated it in parts per billion increase. Now the testing of past CO2 levels is haphazard at best. The testing of temperature differences from hundreds of years ago is also haphazard. They only started to standardize the testing and equipment in the recent past.

Climatologists are nothing but weather people. They are making predictions. Predictions are a guess. Guesses can and often are wrong. Degreed weather forecasters can't even be guaranteed right 24 hours in advance. This makes them on the same level as fortune tellers and palm readers.

The climatologists have found a gold mine in being hired guns to scare people falsely into believing we are doomed They have a vested interest in getting the governments to hand over huge sums of money to them to give what has been proven to be faked science. Why do they fake this science? Well it is so they can show they are relevant and need more money to push the agenda. They want a huge shift in resources to fund a new industry. This green industry is proving very lucrative to wealthy people that get a ton of money thrown at them from our taxes to subsidize. The politicians get their cut by campaign contributions and being able to sit on the boards themselves or family and friends do so at a huge salary or stock that will inflate as more tax monies are shifted to their subsidization. (Gore has become very wealthy by this)

If this was a true science then there would be no need to falsify studies, delete any contrary data, making sure that only other like minded people peer review their work. No science is ever conclusive and never will be. To say that it is showing ignorance. It is an interesting hypotheses and maybe could be looked at more but there needs to be openness and an ability to absorb contrary ideas and thoughts and have a real dialogue.

Remember this.

4.0 percent. Add 300 PPM's and the percentage is still 4.0.

Edited December 7, 2011 by luckytxn