Shell, the oil and gas giant with billions of dollars invested in Australia, says a dysfunctional and enormously complicated system of regulations is putting the transition to clean energy at risk even as it readies to spend big on renewables.

Shell Australia chairwoman Cecile Wake said obstacles for gas developments and large renewables projects threatened to derail progress towards 2030 climate targets. Labor wants to cut carbon emissions by 43 per cent on 2005 levels by the end of the decade, a goal that appears increasingly unreachable.