By Susanna Twidale LONDON (Reuters) – The use of cheap carbon offsets by companies to meet net zero targets could curb their efforts to cut emissions and slow the delivery of climate goals, Britain’s climate change advisers said on Thursday. Many UK listed companies such as Shell have set net zero emission targets, saying they would need to buy or generate carbon credits to offset residual greenhouse gases. Offset credits, based on projects for planting trees or switching to less polluting fuels, currently trade in an unregulated, voluntary market with many different standards and approaches. …