Reserve Bank governor Philip Lowe says Australian business are feeling the "heavy weight of uncertainty", but should still be optimistic because of the buffers built into the economy.

In a speech in Melbourne on Tuesday, Dr Lowe cited a long list of uncertainties facing businesses, including the Chinese economy, technological change, the local and global political environments, high household debt, and the prospects for the “extraordinary global monetary expansion” that’s held interest rates near zero for long periods…