Moving from renewable to nuclear energy could also put Australia on the global pathway to a 2.6C temperature rise, it found, potentially causing economic and environmental harm.
The authority issued the findings of its analysis on Monday, which compared forecasts from Australia's Energy Market Operator and modelling on Australia's potential nuclear reactor rollout by Frontier Economics.
The report, which was welcomed by environmental groups, comes amid heated debate over Australia's energy future before the next federal election that is due to be held before May 17.
While the Labor government has pledged to pursue renewable energy projects to meet a 43 per cent emissions cut by 2030, the Coalition announced plans to build seven nuclear power plants across Australia if it won government.
But the report into the impact of a switch to nuclear power found the move would add two billion more tonnes of carbon emissions to the environment by 2050, including one billion tonnes produced by the electricity sector alone.
Moving to nuclear energy would also mean Australia would miss its legislated 2030 target of cutting emissions by 43 per cent and producing 82 per cent zero-emissions energy as it would not meet the goal until 2042.
Nuclear power would deliver an emissions reduction of 37 per cent by 2030 and 39 per cent by 2035, the analysis said, compared to 42 per cent and 50 per cent for the current renewable energy plans outlined by the market operator.
The findings proved only one pathway would deliver rapid emission cuts, Climate Change Authority chair Matt Kean said.
"Having examined the emissions impacts of these two pathways, the Climate Change Authority's view is that staying Australia's current course is the only viable option," Mr Kean said.
"Prioritising nuclear at this time would be inconsistent with Australia's national emissions reduction priorities and commitments."
The analysis also found pursuing nuclear energy would put Australia on a path to a 2.6C rise in temperature, which was expected to result in social, environmental and economic harm.
Both energy transitions were expected to deliver challenges, however, and the authority noted under the renewable energy pathway "the deployment of low-emissions infrastructure will need to accelerate" to meet targets.
Environment and energy groups welcomed the report's warnings, with Climate Council chief executive Amanda McKenzie saying the figures showed pursuing nuclear energy could delay Australia's progress by years.
"We need proven solutions like renewable power backed by big batteries that cut pollution now, not a reckless delay that locks us into climate catastrophe," she said.
Australians for Affordable Energy spokesperson Jo Dodds said the report answered questions about nuclear energy but more remained about its cost to build and its cost to household budgets.
"We need to have a serious talk about our energy choices," she said.
The Coalition plans to build nuclear plants at Mount Piper and Liddell in NSW, Loy Yang in Victoria, Tarong and Callide in Queensland, Port Augusta in South Australia, and Collie in Western Australia at an estimated cost of $331 billion over 25 years.
