The three methods by which we can reduce the problem of waste disposal are :
(i) Adopting the $5\mathrm{R}$ approach i.e;-Reduce, Reuse, Recycle, Refuse and Repurpose.
(ii) Segregation of waste into biodegradable and non-biodegradable waste.
(iii) Conversion of waste into useful components like biogas and then using compost as a fertiliser. BAL
OR
Ecosystem refers to the interaction of all the biotic and abiotic components present in a particular area. Energy flows across the trophic levels following the $10\%$ law. Only $10\%$ of the energy available to a trophic level is passed on to the next trophic level.(i) For example $10,000\mathrm{J}$ energy is available to producer.
(ii) Then $1000\mathrm{J}$ energy will be available to primary consumer.
(iii) $100\mathrm{J}$ energy will be available to secondary consumer.
(iv) $10\mathrm{J}$ energy will be available to tertiary consumers.