Concerns about the economic impacts of achieving deep cuts in emissions are a pivotal issue in achieving the political support required for emissions reductions. We assess a widespread reference point bias in the communication of economic modelling of climate policy impacts, and find it significantly reduces public support for emissions reductions. At least one in five Americans and Australians incorrectly believe that reducing emissions would result in incomes falling from current levels – triggering loss aversion – rather than incomes rising more slowly. Avoiding this misunderstanding results in support being up to 23 percentage points higher than when impacts are presented as reductions in income from current levels. This suggests that clearly communicating that incomes continue to rise could have a larger effect on support for emissions reductions among US and Australian citizens over the next few years than increased public confidence in climate science. We conclude that improved communication of policy impacts, including that ambitious stabilisation goals are consistent with strong trend economic growth and rising incomes and employment, has a crucial role in facilitating an informed democratic response to climate change, and may be necessary for achieving a political mandate for global action.