Crops - Critical Role in Atmospheric Carbon Dioxide

Each year, the planet balances its budget. 

The carbon dioxide absorbed by plants in the spring and summer as they convert solar energy into food is released back to the atmosphere in autumn and winter, in the northern hemisphere. Levels of the greenhouse gas fall, only to rise again, as summer crops in the south take up more CO2.

But the budget has gotten bigger. Over the last five decades, the magnitude of this rise and fall has grown nearly 50 percent in the Northern Hemisphere, as the amount of the greenhouse gas taken in and released has increased. Now, new research shows that humans and their crops have a lot to do with it, highlighting the profound impact people have on the Earth’s atmosphere.

In a study published Wednesday, Nov. 19, in Nature, scientists at Boston University, the University of New Hampshire, the University of Michigan, the University of Minnesota, the University of Wisconsin-Madison and McGill University show that a steep rise in the productivity of crops grown for food accounts for as much as 25 percent of the increase in this carbon dioxide (CO2) seasonality.

It’s not that crops are adding more CO2 to the atmosphere; rather, if crops are like a sponge for CO2, the sponge has simply gotten bigger and can hold and release more of the gas.

With global food productivity expected to double over the next 50 years, the researchers say the findings should be used to improve climate models and better understand the atmospheric CO2 buffering capacity of ecosystems, particularly as climate change may continue to perturb the greenhouse gas budget.

We need to remember that plants are a critical feature in the CO2 balance.  Grow more of them!!

There is more here - [ where this info came from] - http://www.news.wisc.edu/23298

Sunflowers - an iconic crop

Biochar May Also Sequester Carbon Dioxide

'Biochar' is the name for charcoal when it is used as a soil amendment. People add charcoal to land in order to increase soil fertility and agricultural productivity.  Water holding capacity in soils is also usually increased.

In addition to these benefits, researchers are now saying that biochar has potential to mitigate climate change as it can help sequester carbon and thus cut our greenhouse gas emissions.

Sean Case, a PhD student at the US NERC's Centre for Ecology and Hydrology (CEH) and lead author of the study says: "We've shown that adding biochar suppresses CO2 emissions very significantly over several years... Previous studies have found this effect in the lab and over short periods, but this is the first time anyone has looked at bioenergy crops in the field, and at the effects of biochar over a long period."

Results of the study show that by applying biochar before planting energy crops, soil greenhouse-gas emissions can be cut by around a third.

Researchers studied a plantation of miscanthus, a perennial grass which is harvested for fuel. They monitored how much CO2, nitrous oxide and methane came from the plot's soil over two years. They also monitored soil emissions under controlled conditions in the lab.

The plots that had been treated with charcoal emitted 37% less greenhouse gases than neighbouring plots that hadn't, while in the lab the impact was 55%. Most of this came from cutting CO2 emissions, with methane playing no significant role and only a small nitrous oxide component.

"There's a lot of interest at the moment in the potential of bioenergy crops to sequester carbon in the soil, because unlike arable land these crops aren't ploughed every year so the carbon is not being regularly disturbed," says co-author Dr Jeanette Whitaker of CEH. "Biochar contains a lot of carbon in its own right, so adding it to the soil is already having an immediate sequestration effect, but our research suggests that it also reduces the CO2 emitted by soil respiration, which makes the case for using it even stronger. It's about maximising the sustainability benefits of bioenergy crops."

Whitaker explains that in the long term, it is unlikely people will use wood as biochar. Instead, biochar can be made out of anything from municipal waste to chicken manure.

Different regions will have different availability of feedstock products, with crop residuals common.

 

 

 

Capturing CO2 with Nickel

Sounds as if serendipity is alive and well..........but the concept works and is cheap and easy.  If it works well once scaled up then the implications are potentially major.......think of all the power stations around the world! 

British researchers have discovered that sea urchins use nickel particles on their exoskeletons to effectively capture CO2 and turn it into a solid form, an intriguing finding that could offer an inexpensive way to capture and store carbon from fossil fuel-fired power plants.

Scientists from Newcastle University were studying how marine organisms absorb CO2 to make shells and skeletons when they discovered that sea urchin larvae have a high concentration of nickel on their exoskeletons, which helps them absorb CO2.  When the researchers added nickel nanoparticles to CO2-saturated water, they discovered that the nickel completely removed CO2 and turned it into calcium carbonate, a chalk-like mineral.

Current efforts to capture and store carbon dioxide from power plants involve either pumping it underground or using an enzyme called carbonic anhydrase to convert it to calcium carbonate.  But both methods are expensive, and the Newcastle researchers say that using nickel to capture and store CO2 bubbled through water could be a thousand times cheaper than employing carbonic anhydrase. “

 

It seems too good to be true, but it works,” said Lidija Siller, a physicist at Newcastle.

 

The research was published in Catalysis Science & Technology.

 

 

Using Livestock to Reduce Carbon Emissions - YES!

Cows have been pilloried as the great methane producer, and as the most potent greenhouse gas emitter of all. There are a lot of cows around the world!

Recent thinking now says that it is not cows as the culprit, but rather their management, particularly when fire is included in the system, as it commonly is.

Reduce the use of fire, often used to remove excess forage, while enhancing the consumption of forage by livestock in a way that encourages regrowth eg Savory grazing system option may offer a smart option to actually reduce greenhouse gas production, even if the forage is of poorer quality at times.

It is known that higher digestibility forage does reduce methane production in the livestock gut system, although not all plants have high digestibility, particularly in the tropics. But independent of that, livestock act as the great recyclers of carbon, by consumption and manuring, rather than seeing it lost in a fire.

It is a complex argument, with more detail here -
http://qcl.farmonline.com.au/news/nationalrural/livestock/cattle/cows-conserving-carbon/2307077.aspx?storypage=0

But the essence of it is that cows might actually be useful in the soil carbon story!

About time there was some enlightened thinking, for livestock is definitely NOT going away anytime soon

Carbon Science - There is More Phytosynthesis Occurring!

It is not all doom.....recent experiments and measurements have shown that current phytosynthesis - globally - is about 25% more than has previously been calculated.

The work is based on isotopic analysis of atmospheric carbon dioxide, but essentially follows flows of oxygen and carbon dioxide in and out and through the atmosphere.

Plants take up CO2 and emit oxygen, and from that, using isotope analysis total phytosynthesis is estimated..........and it is a lot more than previously thought.

It will have considerable effect on the performance of the climate change models, but this nett phytosynthesis increase still has to be incorporated into the large and complex models used.

Read more details here in a CSIRO media release-
http://qcl.farmonline.com.au/news/nationalrural/agribusiness-and-general/general/new-leaf-turns-for-carbon-science/2308093.aspx?storypage=0

BUT.....is it possibly related to more CO2 in the atmosphere boosting plant utilisation, seen as a response to more CO2 in the atmosphere? That is not mentioned.

And there is more as well - http://www.enn.com/top_stories/article/43340 with this story also reporting an increase in plant productivity via uptake of carbon - essentially the same data as above but reported in a different way, referring to productivity of land plants. Remember, they produce oxygen!