Biodiversity
This vast library of millions of different species and billions of genetically distinct populations is what is biotic diversity or biodiversity. Any assessment of the number of species on this planet is only guess work. It is estimated that there are between 8 million and 10 million different species on this planet. Of these only 1.5 million have been identified. About 90 percent of the named species occur on land and are identified from the temperate region of North America, Europe, Russia and Australia. May be, because this is where most scientists are located. Indian biodiversity is rich. With just two percent of the world’s landmass, it has about 5 % of living resources, one third of which are land bound. It has been designated as one of the 12 mega diversity states in the world. The living resources include 45,000 species of plants, about 370 mammals, 1200 birds, 60,000 insects, 180 amphibians, 1700 fishes and 400 reptiles. India has more than 75 % of the 425 families of flowering plants found all over the world and has a very large network of 497 sanctuaries and89 national parks.

Green waste is biodegradable waste, usually from gardens and parks, and includes grass, hedge trimmings, leaves and tree trunks. It can be used to produce energy in biomass power stations and receives a renewable energy subsidy in Germany. It can also be recycled as compost, which reduces the extraction of peat – an important sink for CO2. However, composting does not receive financial support in Germany. The EU is currently developing policy to encourage composting and develop standards for composting across the EU1.

The research compared the environmental benefits of energy recovery from green waste and of recycling green waste using 81 samples. It analysed the CO2 balance of each system by estimating the release and savings of CO2 at the different stages of the process chain. For energy recovery this included the transport, shredding, incineration and the CO2 saved from the renewable energy produced. For recycling this included stages such as transport, composting and CO2 saved by replacing peat. Four different types of green waste were considered that differed in their amount of wood, herbaceous/grassy material and soil.

The results demonstrated that waste with a high percentage of wood produced the most CO2 savings for both composting and energy recovery whilst those with only herbaceous and soil components produced the least savings. The CO2 savings from energy recovery varied from 126 to 1040kg of CO2 saved per tonne of green waste, depending on the type of waste and its composition. The CO2 savings from recycling varied from 259 to 1193kg of CO2 per tonne of green waste, again depending on the type of waste. This indicates that the environmental gains, in terms of CO2 savings, were similar for both energy recovery and recycling of green waste.

Notably, green waste with a high percentage of herbaceous/grassy content and soil content had twice the CO2 savings from recycling as from energy recovery. This is probably because this type of waste has low heating values, due to high water and ash content, and is therefore better for composting purposes.

The researchers suggested that energy recovery and recycling of green waste should be judged as complementary systems. It is unlikely that one method on its own will achieve the desired reduction in CO2 levels and a combination is more likely to lead to a significant decrease in greenhouse gas emissions. As such they recommend that recycling of green waste be awarded equivalent financial support as the use of green waste to produce renewable energy.

One of WaterAid’s projects in India has found a novel approach to tackle this dilemma and generate income. Their solution lies with worms.

The community living in the Kalmanthai slum in Tiruchirapalli has worked hard to rehabilitate and build communal sanitation blocks for men, women and children.

They have also established water supply projects and credit schemes which they manage themselves.

The slum is adjacent to a wholesale banana market where truckloads of fruit, leaves and stems arrive every day. Discarded produce litters the area. With no proper disposal systems the community groups realised they would have to manage this and the other waste in the slum to ensure they had a clean environment to live in. WaterAid’s partner, Gramalaya, suggested the community ran a pilot vermiculture project.

Vermiculture uses worms in a controlled environment to do what they are best at- converting organic waste into nutrient-rich compost in nature’s way of recycling.

Members of the community groups underwent training and initiated a small-scale trial project investing Rs.2,200 (£29) they had raised from the sanitation blocks. They bought 4,000 red worms, Eisenia foetida, commonly known as the red wiggler or manure worm, which are best suited to composting.

Encouraged by the initial results the community then set up a larger scheme. An area of land by the communal toilet blocks was set aside with a small shed and composting arrangements for the worms.

Now in every 45 day cycle, for an investment of Rs.500, nearly one tonne of compost is produced. The compost is packed in bags and sold for Rs.5 per kilogramme, making nearly Rs.3000 per cycle.

The success has spread to other slum communities and individual households, which are now also carrying out vermiculture projects. The original project now even breeds and sells worms to those wishing to follow its example. But vermiculture isn’t only a solution in urban areas; another of WaterAid’s partners in India, REEDS, is now implementing a large-scale vermiculture project with rural farming communities in Andra Pradesh.

This scheme shows a highly successful and profitable way of waste disposal that provides communities with employment and funds to carry out their own future development work. As the members of the community proudly claim the scheme is ‘generating wealth from waste’.