India can consider developing a robust domestic emission trading system where the private sector participates and sells retroactive, current and future credits, according to global consulting firm PricewaterhouseCoopers (PwC).Besides, there is a need for continued efforts to de-risk and encourage private sector investment in low-carbon technologies, it said in a report titled 'Shades of Green: Reflections on COP25.'The 25th Conference of the Parties (COP) -- the annual meeting of the signatories to UN Framework Convention on Climate Change (UNFCCC) -- concluded recently at in Madrid in Spain.While signatories deferred the decision on the emissions trading system, they re-emphasised the need for enhanced emission reduction targets from all countries.For India, said PwC, risks may arise owing to cancellation of tenders, import duties, land acquisition-related uncertainties. Policy interventions (for example standardisation of bid criteria) and financial instruments (for example loan ...