"In a time of universal deceit telling the truth is a revolutionary act." -George Orwell

Posts Tagged ‘Soil Carbon Storage’

Say So Long To Soil: The ‘Unfolding Global Disaster’ Happening Right Under Our Feet

In Uncategorized on January 8, 2016 at 8:01 pm

Oldspeak: Old story. We’re running out of soil. Only it’s getting worse. It took us about a century and a half to destroy half of Earth’s topsoil, and in the last 40 years, we’ve exterminated another third of it.”This is catastrophic when you think that it takes about 500 years to form 2.5 cm of topsoil under normal agricultural conditions.” -Duncan Cameron.  Meanwhile, ecocidal Concentrated Animal Farming Operations (CAFOs) and large-scale industrial agricultural operations continue to gobble up land worldwide, destroying forests, poisoning water sources and eradicating habitats for untold flora and fauna at an ever-increasing pace. When you consider that we probably don’t have 500 years to replenish the lost soil, nor seemingly the inclination, this is not good. Especially given the fact that soil is a major carbon sink. Happy New Year Kids! -OSJ

Written By Natasha Gelling @ Think Progress:

With all that’s going on in the world — from record-breaking warm spells to rapidly melting ice sheets — it’s easy to ignore something so seemingly mundane as dirt. But scientists at the University of Sheffield’s Grantham Center for Sustainable Futures suggest that we ignore dirt at our own peril.

Nearly a third of the world’s arable land has been lost over the past four decades, according to a new report, released to coincide with the Paris climate talks earlier this month. Experts at the the University of Sheffield called this soil loss “an unfolding global disaster” that directly threatens the agricultural productivity of the planet.

But soil erosion isn’t just a problem for food security — which is expected to become even more pressing as the world’s population booms and land available for food production wanes. Soil erosion is also tied to the climate, as the world’s soils represent a massive carbon storage system, containing three times the amount of carbon that is currently in the atmosphere.

“If the soil carbon reserve is not managed properly, it can easily overwhelm the atmosphere,” Rattan Lal, director of the Carbon Management and Sequestration Center at Ohio State University, told ThinkProgress in April.

The University of Sheffield report places most of the blame for soil erosion on what it calls unsustainable farming practices, which require large amounts of fertilizers and tilling to boost crop yields. Switching to a more sustainable model of intensive agriculture, the report urges, can help offset soil loss.

Right now, the report found that plowed fields lose soil to erosion at a rate 10 to 100 times greater than soil formation, meaning that the Earth is currently losing valuable land faster than it can be naturally replenished. Replenishing topsoil naturally is not a quick process — it takes about 500 years to replenish just 2.5 cm of topsoil. According to the World Wildlife Fund, about half of the world’s topsoil has been lost in the last century and a half.

“Soil is lost rapidly but replaced over millennia, and this represents one of the greatest global threats to agriculture,” University of Sheffield biology professor Duncan Cameron, co-author of the report, said in a press statement. “This is catastrophic when you think that it takes about 500 years to form 2.5 cm of topsoil under normal agricultural conditions.”

Over-plowing fields constantly disturbs top soil, exposing the microbes that live within it to oxygen and releasing its stored carbon. That, in turn, impacts soil’s ability to store more carbon. It also degrades the soil’s structural integrity, impeding its ability to absorb water and act as a buffer against floods, or store water for plants. Degraded soil can wash away more easily during extreme precipitation events, causing rivers and streams to become flooded with silt and sediment, which can impact ecosystems in the water.

Degraded soil is also less fertile than non-degraded soil in terms of agricultural productivity — a worrisome reality for a planet that is expected to need to increase its agricultural production 50 percent by 2050. According to the United Nations, 95 percent of our food comes from the soil, but about one-third of the world’s soils are currently degraded. For sub-Saharan Africa, that number jumps to about two-thirds, which the Montpellier Panel — an international group working to support national and regional agricultural development and food security priorities in sub-Saharan Africa — estimates costs the region about $68 billion per year in lost productivity. If topsoil loss is not slowed or reversed, the U.N. estimates that all of the world’s topsoil could be gone within 60 years.

In order to slow or reverse the trend of soil degradation, the University of Sheffield report suggests a few tweaks to the currently agricultural model. First, they suggest a more hands-on approach to soil management with cover crops and no-till soil, both of which can help boost soil health by keeping soil microbes from being exposed to oxygen and preserving a system of roots that keeps soil more tightly packed. The report also suggests weaning the world off of synthetic fertilizers and returning to the age-old but currently-underused tradition of applying night soil — also known as human sewage — to cropland, which the report argues can help restore nitrogen and phosphorus back to the soil.

As part of the U.N. climate talks, the French government launched a program aimed at studying the best methods for restoring soil health and aiding carbon sequestration. Dubbed “4 pour 1,000,” as a nod to the idea that a .4 percent increase in soil carbon annually would offset human emissions, the program is a partnership between the French government, agricultural development bodies like CGIAR, and several developing nations. The project hopes to sequester 25 megatons of carbon while boosting farming yields by 20 percent.

“The good thing is that no one disagrees that increasing soil carbon is good for agriculture, is good for the environment, good for food security,” CGIAR CEO Frank Rijsberman told ThinkProgress during the Paris conference. “If we can do it in a stable way, it captures carbon and reduces emissions. It can be a double or triple win.”

 

Massive Stores Of Carbon In Earths Soils Higher Than Projected, More Suseptible To Warming Than Previously Thought

In Uncategorized on September 22, 2014 at 9:09 pm
tundra

Colder soils are more vulnerable to releasing extra carbon in a warmer world

Oldspeak: “Researchers found that microbes in the soil were more likely to enhance the release of CO2 in a warming world.  Soils from colder regions and those with greater amounts of carbon were seen to emit more as temperatures went up. The world’s soils hold about twice the amount of carbon as the atmosphere… The research team found that soils from boreal regions and the Arctic were impacted the most…The scientists aren’t sure about the mechanism of action involved in this process… Whatever about the mechanism, the research implies that current soil carbon and Earth system models may be underestimating the impact of warming on the huge reserves that sit in the ground…. According to Dr Karhu, this level of increase in colder regions raises concerns as more than half of the carbon that’s stored in soils in the world is found in these locations. “It means that more carbon can be released from the northern soils than is projected by the models at the moment. This is worrying because these soils have a lot of carbon.” Matt McGrath

SO. There’s That. As temperatures increase,  twice the amount of carbon that is already in the atmosphere and being increased every day by hyperconsumptive human activity will be released into the atmosphere from earths rapidly deteriorating soils. The areas of soil that are heating most drastically, the arctic and antarctic regions are the same areas where the soils are most vulnerable to heating, and where the most carbon is stored in the soils. This irreversible non-linear feedback loop is already in progress. Researchers have no idea how this action works, but know our climate models do not account for this reality. There is noting to be done. Contemplate and accept this reality. TICK, TICK, TICK, TICK, TICK, TICK, TICK.” -OSJ

By Jeff Spross  @ Think Progress:

The Earth’s soils play an important part in managing climate change by storing carbon, and thus keeping it out of the atmosphere. But research published Wednesday in Nature suggests that as global temperatures rise, the ability of soils to perform that service goes down.

The researchers tested 22 different soil samples from different points along the climatic gradient, from the Arctic all the way to the Amazon. It’s the microbes in each sample that determine how much carbon the soil stores versus how much it releases over a given time. So the researchers applied different temperature changes to each sample over a 90-day period to see how the mircobes would respond.

The question is an important one because soils and their microbes around the world store more than twice as much carbon as the atmosphere does, and release around 60 billion metric tons of that carbon into the atmosphere every year. Some of that carbon is absorbed by other parts of the planetary ecosystem — forests or the ocean, for instance — and eventually makes its way back to the microbes again before being re-released into the atmosphere.

But if temperature changes alter the microbes’ respiratory behavior, they could be releasing enormous amounts of carbon at greater rates, meaning there would be more carbon in the atmosphere at a given time. That, in turn, would exacerbate climate change.

Up until now, the general assumption has been that the microbes would probably acclimate to temperature changes: after briefly changing the way they take in and release carbon, the microbes would get used to the new temperature and settle back into their previous pattern.

But Kristiina Karhu from the University of Helsinki, the Nature study’s lead author, told the BBC that based on the researchers findings, that wasn’t what happened.

“We show that for these 22 soils, this type of acclimation of microbial respiration doesn’t really happen,” she said. “Sometimes the opposite happens, in response to long-term temperature change, the microbes enhance the short term effect of temperatures so that the sensitivity of respiration gets actually higher.”

In other words, as the temperatures went up, many of the microbes tended to release more carbon.

The effect was particularly pronounced in soils from northern climates, such as the Arctic and boreal regions. “Microbial community response increased the temperature sensitivity of respiration in high latitude soils by a factor of 1.4 compared to the instantaneous temperature response,” according to the study. As Karhu pointed out, that’s worrying because northern soils and their microbes store more carbon than soils at other latitudes.

“The soils that had this enhancing response were also soils that had a high carbon to nitrogen ratio,” Karhu said. “So it could be something in this interaction between carbon and nitrogen cycles, and there are some studies that suggest that maybe the enzymes related to nitrogen may be more temperature sensitive than the carbon related enzymes.”

It’s an example of what climate scientists call a feedback loop. Human beings pump more carbon into the atmosphere, which drives up global warming. But then that warming also changes the Earth’s natural ecosystems, so that the natural carbon cycle also begins dumping more carbon into the atmosphere than it did before, driving global temperatures up still further.

As hard as scientists work to build models to accurately project ecosystem changes and the effects of global warming, it’s a horrendously complex system — and this research suggests the models are underestimating the amount of carbon northern soils especially will release as global warming proceeds.

“Big advances have been made in recent years, and there are now models that simulate key microbial processes,” said Iain Hartley, another author of the study, told the BBC.”We have a great opportunity to really advance this subject, and improve predictions of rates of carbon dioxide release from soils under global warming, but there is still a huge amount that we need to understand better.”

The complexities abound: some forms of fungi grow more profusely in hotter temperatures, and one type of fungi in particular — ecto- and ericoid mycorrhizal (EEM) fungi, to be specific — can affect the ability of soil to store carbon. Because EEM fungi changes the decomposition process in soil, places heavy in EEM fungi end up storing carbon longer in the ground. And the difference can be dramatic, altering the amount of carbon released into the atmosphere at a given time by as much as 70 percent.