Australia's Prime Minister on Thursday denied his climate policies had caused unprecedented bushfires ravaging the country and insisted his government was doing enough to tackle global warming.As blazes that have scorched swathes of countryside continued to spread and the country's largest city was cloaked in hazardous smoke, conservative leader Scott Morrison defended his climate record, saying Australia was "doing our bit".His comments came after weeks spent refusing to speak about the link between climate change and amid deadly fires described by the emergency services as unprecedented in number and scale for the early bushfire season."The suggestion that any way shape or form that Australia - accounting for 1.3% of the world's emissions... are impacting directly on specific fire events, whether it is here or anywhere else in the world, that doesn't bear up to credible scientific evidence," he told ABC radio.As more people in the southeast of the country were told to evacuate their homes and schoolchildren in Sydney were again forced to play indoors, Morrison dismissed mounting calls for action.Australia, he said, was "doing our bit as part of the response to climate change" and sought to frame the issue as a global concern.Scientists, former fire chiefs and residents touched by bushfires have all drawn the link between this season's more intense fires and climate change.Drought, unseasonably hot, dry and windy conditions have fuelled the unprecedented blazes. Scientists believe many of those factors are made worse by rising global temperatures.On Thursday bushfires burned across every region of Australia with residents in Victoria warned to leave high-risk areas and officials in New South Wales reporting more than 600 homes have been destroyed in recent weeks.Morrison is facing calls to cut greenhouse gas emissions and rapidly transition to renewable energy - a sensitive debate in light of Australia's lucrative mining industry.Australia has committed to globally agreed climate targets to help limit warming, but its emissions continue to rise and targets are only being met with the use of some creative carbon accounting - using credits gained in past decades.While Australia's burning of fossil fuels accounts for only a fraction of global emissions, coal dug up Down Under and burned around the world makes the country a major emissions exporter.'Code red'Devastating fires along the country's east coast have claimed six lives since mid-October.Now the fire danger has moved into states further south, with a so-called "Code Red" - the highest possible fire risk in Victoria - being declared in the state's northwest for the first time in a decade."What that means is that if we see fires in those areas they will be fast-moving, they will be unpredictable, they will be uncontrollable," emergency management commissioner Andrew Crisp said.Country Fire Authority chief Steve Warrington told people living in rural areas to leave for the safety of cities."We are saying, 'do not be there, do not be there when a fire occurs, because you will not survive if you are there'," he said. "There is a good chance if a fire occurs that your home will be destroyed."The fire danger was also elevated to "severe" in the island state of Tasmania off mainland Australia's southeastern coast, where a total fire ban was declared.For the second time in three days, smoke from bushfires blanketed Sydney, Australia's biggest city and an area that is home to more than five million people, sending air quality plummeting to hazardous levels.In South Australia, the state capital Adelaide was also shrouded in bushfire smoke and residents were being told to stay indoors for health reasons.More than 110 fires are still burning in worst-hit New South Wales and neighbouring Queensland, while in South Australia more than 40 fires broke out during catastrophic fire conditions on Wednesday. The country is bracing for challenging fire conditions to continue throughout the Southern Hemisphere summer.