In Australia, there is a growing realisation among exporters that they cannot rely on China to keep buying large quantities of iron ore, infant milk formula and other commodities. Dwindling confidence in China’s outlook is prompting investors to short the Australian dollar, erasing more than US3¢ in value this month. “The risks around the Chinese outlook and its longer-term growth mean Australia cannot rely on the China/commodity boom indefinitely driving national income,” AMP Capital’s chief economist Shane Oliver said this week. His warning was echoed in messages from Australian companies this week. David Bortolussi, a2 Milk’s chief executive, said on…