Here is a good informative article on effects and researches, and what people can do themselves. With Links to sources included:http://shalinry.org/charcoal-agriculture-and-climate-change/2008/07/ Also, I think that it might be most useful to collect overgrowth from overnutrified waters. Growth like Water Hyacinth (Scientific name: Eichhornia crassipes), which grows as virulent "pest" in wide variety of areas, from the shores of Lake Victoria in Africa to South Indian lakes, pools and wells.  Part of that plant mass can be then sundried, and burned into charcoal (while using the charcoal making heat from burning the resulting gasses, for local community energy and heating and cooking needs), which can then be ground into fine charcoal powder. Other part of the plant mass can at the same time be left to rot in airless spaces (like large plastic bags or clay chambers) which will result in biogas starting to push out from that airless space, which can then be used just like the burnable fuel gasses that come from the charcoal making above. After this rotting process is over and no more biogas manifests... the remaining "fresf" rotten plant matter slurry can be mixed with the produced charcoal powder.And that is a Terra Preta mixture of some sorts, to be spread on top of frigid sandlands, to cause soil life within them, to turn them into more or less permanently farmable lands. This series of actions could thus take nutrients away from soiled waters thus cleaning them up slowly... and moving those nutrients into depleted lifeless sands to make them alive once more. Asides from possible local benefits, this practice could prevent many emissions of biogas (mostly methane) into air, from rotting water vegetations as they would now be rotting within gas collectors. Also, the carbon in the Terra Preta mixture seems to stay within the newly made soils... for thousands of years at least, if not forever even.While biogas and charcoal making caused gasses are burned for local use... amount of carbon dioxide results as exhaust from that. That could further be guided for gardened plants to breathe as it gives the plants benefits of withstanding more heat and turning that heat into plant growth. The less harmful carbon dioxide could be thus used at least partially... and also turned into breathable oxygen as well for some measures, as that is what the plants breathe out after breathing in carbon dioxide. In summary: Balancing the nutrients in local environments for more harmonious existence for life. Benefits for local household and communities in form of produced energy, vegetables, fruits, fiber plants, crops, from increased farming areas. Benefits for nations as their climate change emissions and "carbon footprint" can be thus reduced by rural peoples activities, thus benefitting them in international emission level agreements deals. Benefitting global climate and atmosphere, and thus all life on planet earth, by taking away green house gasses from atmosphere and tying them into ground for new living soils. Benefits for local ecosystems as well. All the technologies needed seem to be quite simple and doable by local peoples from readily available local materials.Depending on the location and it's conditions, this technique could be added to such tools as monsoon catchment farming field placement and steppe wells, and India-area technique of using a mixture of cow dung, cow urine, and raw sugar, to create organic farming fertilization mixture.