A Review of Biochar for Sustainable Soil Health

A Review of Biochar for Sustainable Soil Health

A recent article published in Pedosphere in October (Lone et al. 2015) gives a great summary review of the relationship between biochar and soil sustainability.  The article can be downloaded here.   The following is a summary of points made in the article. Continue reading A Review of Biochar for Sustainable Soil Health

Mining waste reaches Brazilian coast

Mining waste reaches Brazilian coast two weeks after BHP dam collapse

An aerial view of the Rio Doce at an area where the river joins the sea, on the coast of Espírito Santo in Regência village. Photograph: Ricardo Moraes/Reuters Source: http://www.theguardian.com/world/2015/nov/23/brazil-dam-collapse-mining-waste-reaches-ocean-rio-doce

Here is an update on a post I did earlier this week related to mining risk.  The Guardian has posted video of the tailing material from the mine in the Brazilian state of Espírito Santo reaching the coast.  According to projections from Brazil’s environment ministry, the waste is projected to spread along 5.5-mile (9km) stretch of the coastline, threatening the Comboios nature reserve, one of the only regular nesting sites for the endangered leatherback turtle.

If you need a review of your mine waste management strategies, or help with remediation and reclamation of mine waste and water, email me at andrewharley@ascensionsoil.com.

If you have thoughts around this issue, please comment below.

How mining risk is perceived and a couple of observations

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Citing an article in Journal of Environmental Psychology, an article in the Washington Post discussed how environmental risks are viewed.  Surveying 220 residents in a lead-zinc mining area located in Fenghuang County of China, Zheng et al,(2015) found that:

  • The degree of risk perception of villagers living around the mining site correlated inversely with their degree of involvement in mining risk, referred to as the ‘‘involvement’’ version of the psychological typhoon eye effect;
  • Perceived benefit and perceived harm provided a satisfactory explanation for this ‘‘involvement’’ version of the psychological typhoon eye effect; and
  • Risk perception was negatively related to support for the relevant policy which we viewed as constituting a sort of voting behavior.

People who are more directly involved with the mining process — and, thus, more susceptible to its risks — were less concerned.  Those who stand to benefit more from the mines themselves (for instance, by working and earning money from them) are more likely to perceive their dangers as being lower, and the more the perceived benefit from the mining, the less perceived risk. Conversely, people who saw less benefit perceived greater risk.

The day after this article was published, a tailing storage dam failed at the Samarco Mineração SA mine in Brazil’s mineral-rich state of Minas Gerais impacting drinking water, biodiversity and ecosystems.  In this instance, I was outraged as the devastation.  Now, I had never been involved in this project or even been to Brazil, so why the outrage?  When the Gold King Spill on the Animas River Colorado, occurred in my back yard (relatively speaking) and in an area that I have worked previously and know well, I barley blinked.  It’s only 3 million gallons I rationalized, the river can handle it, and by the time it reaches the Colorado River it will be diluted away.  So why didn’t I care? As a geochemist, understanding the reactions that occur as well as the site specific conditions of the Animas, and other receiving waters (San Juan and Colorado River), I ran the quick model in my head and wasn’t phased – sure the photos were impressive, but at the end of the day, the status of the Animas would return quickly.

The Brazilian dam failure, however ran a different story – 50 million cubic meters (13,208 million gallons) of sludge that has now travelled 500km (300 miles) to the Atlantic Ocean.  The hope is that the ocean will dilute the sludge – someone has done the same calculation that I have but on a bigger scale.  However, there is still a degree of hope and no clear disaster planning.  Somewhere between 3 million and 13,000 million gallons, I became outraged.  So where is the cutoff?  It began making me think about my own perception of risk in the mining sector.  Indeed, a lot of my work is to evaluate how much impact can the environment take before it becomes significant, and in the Brazilian case, this environment could not react until it reached the sea where, hopefully, it will all go away.  Not exactly a strong environmental management strategy.

Naomi Klein in her TED Talk Addicted to Risk discusses the hubris of assuming that engineering can overcome nature.  Part of the thinking pertains to the fact that nature is resilient, therefore we can abuse it.   I have seen it repeatedly during feasibility studies where any environmental concerns are “engineered away” if not just completely ignored – not in all cases, but more times than not.  In some regards, the findings of Zheng et al. (2015) explain my observations, with the proponents of projects who financially benefit by getting the projects funded or permitted, minimize the risks during the feasibility or permitting phase.   They are actively involved and as such the risks seem minimal.  Meanwhile, communities near the proposed projects, with no reward, resist these projects as being high risk.  With this dynamic, it is getting harder to get projects into production.

I also see this as a function of time.  Issues such as acid drainage, water treatment, waste rock management, tailings failure or pit lake development are so far down the road, they are seemed trivial during the mine planning stage.  Getting into cash is of greater concern than worrying about water treatment into perpetuity.  During the economic analysis component of the feasibility analysis, remediation and reclamation activities, coming at the end of the mine life cycle, disappear into the realm of Net Present Value.  Most of the original project planners will also be long gone by the time that these problems appear.  A planner’s focus is to get the project into operation, not closure – as such these risks appear minimal.

With commodity prices down and projects being cancelled or put into care and maintenance, we have an opportunity to re-evaluate how we look at these projects.  Looking at the findings of Zheng et al. (2015), as well as the impacts form recent major releases in Brazil, Colorado and Canada, not to mention historical issues associated with mining, I am becoming more intrigued by suggestions by Naomi Klein in This Changes Everything on how we develop resource projects in the future:

  • Communities should be given greater tools and powers to design the projects that work best for them.
  • Old political habits and structures must be re-invented to reflect new realities as well as past failures.
  • Application of stewardship – taking from the earth but also taking care that regeneration and future life continue.
  • Resistance to high-risk extreme extraction is a desire for a deeper form of democracy, one that provides communities with real control over the resources that are most critical to collective survival – the health of the water, soil and air. What is democracy if it doesn’t encompass the capacity to decide, collectively, to protect something that no one can live without?
  • Development of small-scale mining where activities are controlled by the people who live where the extraction is taking place and who have a stake in the on-going health and productivity of the land.

This was a bit of a rant, and for the record, I am for mining and resource extraction.  We just need to re-think how we are doing it.  I am currently working on several projects developing low impact processing to extract value from mining waste.  If this is of interest to you, or you want to discuss your number one environmental geochemistry struggle, email me at andrewharley@ascensionsoil.com.

If you got value out of this post please comment and share with your network.


Zheng, R., et al. (2015). “The more involved in lead-zinc mining risk the less frightened: A psychological typhoon eye perspective.” Journal of Environmental Psychology 44: 126-134.

Updating Soil Carbon Models to Include the Effect of Soil Erosion

Soil is considered a major store of soil containing more than three times the organic carbon in the atmosphere (Lal, 2003).  Land surface models only account for the effects of net primary production and heterotrophic respiration (King et al., 1997).  An article published this week in Nature Climate Change (Chappell et al., 2015) has proposed that SOC flux should include losses (and gains) due to soil erosion (and deposition).  Looking at several long-term experimental plots in Australia, and estimating net soil erosion using three approaches, the results were incorporated into RothC (a model for the turnover of organic carbon in topsoil) to estimate net C flux with and without soil erosion.  Using this approach, the model showed a consistent under-estimate of net C flux in the presence of soil erosion.

When this approach was adopted across the long-term plots in Australia, Continue reading Updating Soil Carbon Models to Include the Effect of Soil Erosion

Bringing Soils to Life