LONDON — Voluntary carbon markets have shrunk for the first time in at least seven years, as companies including food giant Nestle and fashion house Gucci reduced buying and studies found several forest protection projects did not deliver promised emissions savings. …The decline is also bad news for poorer nations that stand to lose if the flow of funds from multinational companies to fund climate mitigation projects slows. …Demand for carbon credits is on track to fall in 2023, according to two of the top data providers. The number of credits used by companies fell 6% in the first half of the year. …Nestle said it would stop using carbon offsets and was seeking other routes to net zero. “We are moving away from investing in carbon offsets for our brands to invest in programmes and practices that help reduce GHG emissions in our own supply-chain and operations,” it said.