Tony Abbott is “living in the 18th century” when it comes to tackling climate change, Labor has said, after the release of a new report warning that Australia’s temperatures could rise substantially in coming decades.

Modelling by the national science agency the CSIRO and the Bureau of Meteorology has predicted average temperatures in Australia could rise by more than 5C by 2090.

It warned that the “business-as-usual” approach of burning fossil fuels will contribute to soaring global temperatures.

Labor’s climate change spokesman, Mark Butler, criticised Abbott for focusing on the issue of knighthoods which he said “doesn’t reflect national priorities”.

“Instead of indulging his strange personal fascination with the British royals … Tony Abbott would have been much better served spending some time on a serious climate change policy,” Butler said on Tuesday.

“But we know Tony Abbott still lives in the 18th century and refuses to join the rest of us to face this challenge.”

The Greens leader, Christine Milne, said potential changes in climate will derail plans for Australia’s future.

“Australia’s future is grim in the climate sense,” Milne said in Hobart on Tuesday. “All the projections they [the government] want to talk about – about the economic growth, about food and agribusiness – will come crashing down unless we get serious about global warming.”

The Climate Institute has urged the government to invest more in decarbonisation and improve environmental resilience.

The head of the institute, John Connor, said: “This new data reinforces earlier analysis for Treasury that showed large chunks of the Australian economy will be whacked by global warming.”

“Under scenarios of unchecked or part-checked pollution, sectors like agriculture, health, and ecosystems are hit well beyond their ability to adapt.”

“This shows starkly how deep pollution reductions and decarbonisation of the economy is squarely in Australia’s national interest,” Connor said. “This needs to be the guiding principle in the government’s decision this year on Australia’s post-2020 pollution reduction targets.”

The Australian Conservation Foundation warned that “some parts of Australia could become uninhabitable”.

“These projections show Australia will suffer more extreme heat and drought, having massive implications for agriculture, tourism, water supply and liveability,” Victoria McKenzie-McHarg, the foundation’s climate change program manager, said. “The number of hot days in the country is set to increase substantially.”

“It makes you wonder what it will take to get the federal government to take this issue seriously,” McKenzie-McHarg said.

“This year must become the year our government starts to play a constructive role in the global effort to tackle climate change.”

A spokesman for Ian Macfarlane, the industry minister, said: “The Australian government is committed to tackling climate change and is delivering strong, effective and practical action through its direct action plan and $2.55 bn emissions reduction fund.

“Unlike Labor, the Coalition is tackling climate change without a painful carbon tax that hurts Australian pensioners, families and businesses.”