Kids and biochar: Charcoalab brings terra preta to the classroom

Conventional bioenergy offers a sustainable road to clean and renewable energy. But creative minds take things a step further and have found ways of making bioenergy a tad more radical by tapping its negative emissions potential. The Charcoalab is an initiative aimed at introducing kids and young students in a practical way to the benefits of adding biochar to soils - one of the techniques used to generate carbon-negative bioenergy. With the lab's charcoal kit, teachers from across the world can help their students conduct experiments on biochar in a fun way, and compare data online. The project thus offers an interesting context for lessons about climate change, the carbon cycle, agriculture, soils, and biology. Moreover, it may help in getting international recognition for the technique of storing charcoal in soils as a method for carbon sequestration.

Ordinary biofuels, nuclear energy and renewables like solar or wind power are 'carbon neutral', that is, they do not add carbon dioxide to the atmosphere. But bioenergy with carbon storage (BECS) goes a step further: not only does it not add CO2, it actually alters the carbon cycle by taking the greenhouse gas out of the atmosphere.

There are two main pathways to achieve this: a high-tech and a low-tech route. The technology intensive strategy consists of coupling biofuels and bioenergy production to 'carbon capture and storage' (CCS) techniques in which CO2 is captured from a point source and then sequestered in geological formations like depleted oil fields, unmineable coal seams or saline aquifers. The low-tech track consists of pyrolysing biomass and storing part of it directly into agricultural soils. As the charcoal is stored in an inert form, the soils become carbon sinks that can keep the compound locked up, potentially for centuries.

The technique is actually thousands of years old and sometimes called 'terra preta' (dark earth), referring to the fertile, man-made soils found in the Amazon. These dark soils were discovered by archaeologists who found them to be the key that allowed a civilization to flourish in a region in which agriculture would otherwise have been difficult (previous post). Today, they are of interest again because they could become one of the most effective ways of sequestering carbon and thus help mitigate climate change.

By adding biochar to soils, they have been shown to boost crop yields. This is due to a number of factors, amongst which are the better retention of moisture, a boost to cation exchange capacity and aggregate formation, and, in some cases, an increase in soil pH (earlier post). But researchers are still trying to find out how the old carbon-rich terra preta soils were created precisely. One way to do so, is simply by simulating the technique in modern soils and by measuring the effects of different biochar applications.

The Charcoalab now takes these experiments to the classroom in a fun and hands on way. The initiative was recently launched by Christelle Braun, Phd student in bioenergy at the Technical University of Dresden, who thought terra preta deserved attention from a wider audience. Young people can test the effectiveness of the technique with a kit that contains samples of charcoal, a set of pots with soil and seeds, and instructions on how to conduct trials. Like real agronomists, the 'certified charcoal testers', set up experiments and compare plant growth in charcoal-amended soils versus unaltered, ordinary soils.

The Charcoalab has created a database to which school children from across the world can upload their results and compare their data with those of others online. As the number of experiments grows, the global database will yield interesting scientific results:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: agriculture :: soil :: biochar :: charcoal :: terra preta :: carbon sequestration :: climate change ::

Several schools are already participating in the project, amongst them 20 institutions in New Zealand. The Charcoalab offers teachers a range of educational materials, which allows them to create and illustrate lessons on the carbon cycle, climate change, the substitution of fossil fuels, the history and principles of biochar, and much more.

Rationale
Getting international recognition for charcoal as a method for carbon sequestration has yet to be achieved, although many publications are available which indicate that the presence of charcoal in the soil (which has improved soil fertility), extends beyond 1000 years.

A key challenge is to get research institutes around the world to elaborate on these findings and push this information forward to governments to get policy, implementation and support for the application of charcoal agriculturally. Several initiatives are underway, bundled in the International Biochar Initiative (IBI). In the U.S., first steps towards legislation encouraging trials and research on biochar have been taken (more here).

Developed countries should also be encouraged to support the renewable production of charcoal in the developing world. Several categories of biomass available in poor regions could indeed be used as feedstocks for charcoal production. Positive results already exist for the agricultural application of biochar from bamboo, coconut shell and agricultural residues such as rice husks, corn stover, nut shells or cotton gin waste.

The Charcoalab thinks that if it can get children around the world to conduct the same simple pot trials with the same charcoal and submit their findings, this will result in a much faster indication of whether there is any potential negative effect of using charcoal in soil or if it is at all beneficial.

The simple submission of a pH measurement of the soil at the start and the end of the experiment, complemented with weekly measurements of the height of the plants and, if possible, with pictures showing the differences between the test and the control plants could give a clear indication on the impact of using charcoal.

The Charcoalab is a non-profit and will be financed by the use of free space for advertisement on the packages of the kits and on the website, sold to private companies or NGO's supporting the project. This could provide the opportunity for foundations and academic institutes to send a message to a mass market, not only for children, but also their parents and the wider public and through associated advertising in media channels.

In many countries, the charcoal kit would be eligible for environmental education grant funding. The kits could well be adopted and supported by government departments, with the task of promoting environmental awareness, sustainability or simply encouraging kids to pursue careers in the field of science.

Picture: children from the Matapihi school in Tauranga, New Zealand, conducting their first trial. Credit: Charcoalab.

References:
Charcoalab website.

Biopact: Research confirms biochar in soils boosts crop yields - June 01, 2007

Biopact: Towards carbon-negative bioenergy: U.S. Senator introduces biochar legislation - October 07, 2007

Biopact: Terra preta: how biofuels can become carbon-negative and save the planet - August 18, 2006

Biopact: Terra preta and the future of energy: the Secret of El Dorado - August 19, 2007