What happens if we don’t act to climate change?
THIS year Australians have suffered through one of the worst droughts in living memory, bushfires and a heatwave that saw hundreds of flying foxes "boiled alive".
It also saw the publication of one of the most comprehensive reviews of climate science which delivered a "wildly alarming" report about where the world was headed.
Yet Australia still does not have a climate change or energy policy.
This week there was an extraordinary act of rebellion from NSW Liberal Energy Minister Don Harwin, who used an opinion piece in the Australian Financial Review to accuse the Morrison Government of being "out of touch" on climate and energy policy.
Perhaps some of the doom and gloom from recent reports into the world's changing climate is finally starting to filter through?
Climate change is certainly being taken seriously by many Australians, with the Climate of the Nation report this year showing the number of Australians concerned about it had reached a five-year high.
The report produced by The Australia Institute found 73 per cent of 1756 Australians surveyed were concerned about climate change, up from 66 per cent in 2017.
But Federal Energy Minister Angus Taylor has hit back at pressure from Mr Harwin and other states and territories who want higher emissions reduction targets, suggesting they need to "get back to reality".
So what is the reality on climate change? Here are some facts.
AUSTRALIA HAS WARMED BY 1 DEGREE
On Thursday a new report was released that confirmed Australia had already warmed by 1C since records were first kept in 1910, according to the State of the Climate, a joint analysis released by Australia's Bureau of Meteorology and CSIRO.
As well as a spike in the number of extreme heat days, oceans around Australia seem to be warning and this is contributing to a rise in sea levels, CSIRO director of the Climate Science Centre Helen Cleugh said.
The report confirms the findings of the "wildly alarming" Intergovernmental Panel on Climate Change (IPCC) report, which also noted the world had warmed by 1C.
WE'RE ON TRACK FOR 3 DEGREES
The IPCC report has been hugely influential because it looked at 6000 peer-reviewed studies and involved 91 authors and review editors from 40 countries.
It found current pledges made by countries around the world - including Australia's target to reduce emissions by 26 to 28 per cent on 2005 levels by 2030 - would see temperatures rise by 3C by the end of the century.
Scientists and climate activists have called on countries to ratchet up their carbon-cutting pledges as soon as possible.
Actions taken in the next 12 years until 2030 will be critical in order to have a chance of keeping global warming to 1.5C.
Temperatures are likely to rise by 1.5C between 2030 and 2052 if they continue to increase at the current rate.
WE'LL LOSE THE GREAT BARRIER REEF
The future is bleak for one of Australia's biggest tourist attractions, which is estimated to be worth $56 billion to the country.
The IPCC report found that if the Earth warmed by 1.5C, most of the world's coral reefs would be lost in the next 30 years, although some would survive.
Half the world's coral reefs could be saved if warming was limited to 1.2C.
"This is worth fighting for," coral reef expert and Australian Marine Conservation Society (AMCS) adviser Dr Scott Heron said.
If there was 2C warming, virtually all the world's reefs would be gone from 2050 onwards.
A Deloitte Access Economics report found Australia's Great Barrier Reef currently supported 64,000 full-time jobs.
EXTREME HEAT, LESS RAINFALL
The fire season is now months longer than it used to be in some areas, Bureau of Meteorology climate monitoring manager Karl Braganza said.
The State of the Climate report released this week indicates Australia should get used to horrific bushfire seasons that rage at greater intensities and for much longer periods of time.
There'll be more potentially catastrophic "fire weather" based on hot daytime temperatures, wind speed, humidity and the state of the fuel.
The combination of reduced rainfall - down 20 per cent since 1970 - and higher temperatures will see extended periods of drought become more common, the CSIRO's Helen Cleugh said.
It's not just people who will be impacted by more frequent extreme weather events, in January this year, hundreds of baby flying foxes were "boiled alive" when temperatures soared to 47.3C in Sydney's west.
SEA LEVEL RISE
The IPCC said sea levels were expected to rise by 0.26m to 0.77m by 2100 (compared to 1986-2005) if there is global warming of 1.5C.
It will be 0.1m higher if temperatures rise by 2C and an extra 10 million more people would be exposed to climate risks at this higher level of warming.
Maps on Coastal Risk Australia show the impact of a 0.74m rise in sea levels, with large areas of Bryon Bay, Cairns and Port Douglas underwater. Parts of Melbourne's Southbank precinct would be submerged along with Sydney's Woolloomooloo and the eastern suburbs.
EXTREME MEASURES NECESSARY
It's possible for the world to keep warming to 1.5C but extreme measures will be necessary.
Around the world the use of coal to generate electricity would virtually have to be eliminated by 2050 as part of all the scenarios the IPCC modelled.
This would also need to be combined with other measures such as carbon dioxide removal, changes to agriculture and forestry land use, as well as bioenergy with carbon capture and storage.
Carbon emissions would need to be cut by 45 per cent from 2010 levels by 2030. This would allow carbon emissions to reach "net zero" by around 2050.
If temperatures were allowed to rise above 1.5C it would take a lot more effort to bring this back down by 2100. Techniques to remove carbon from the air would probably have to be used and their effectiveness have been unproven at large scale. Some of them may carry significant risks for sustainable development, the report notes.
A separate report on The Economics Of 1.5C Climate Change found the world needed to act now if it didn't want to turn to risky or expensive measures to block out sunlight.
New "climate engineering" technology may eventually be necessary and this could include "solar radiation management" which involves deflecting sunlight to reduce warming.
Methods include stratospheric aerosol injections, marine cloud brightening, space mirrors and painting roofs white.
Aerosol injections involve spraying aerosols into the stratosphere so that the particles block and reflect the sun's rays, to bring temperatures down.
Marine cloud brightening works in a similar way and involves seeding clouds with a fine spray of saltwater to encourage micro-droplets to form. These micro-droplets scatter incoming radiation and make clouds last longer.
WHAT AUSTRALIA IS DOING
Despite warnings that coal-fired electricity would have to be phased out by 2050 to keep warming to 1.5C, the Morrison Government still wants taxpayers to back new coal projects as part of its Underwriting New Generation Investments program.
Meanwhile businesses and other organisations are calling for the Government to adopt a climate change policy after former prime minister Malcolm Turnbull's National Energy Guarantee was dumped.
Australia's greenhouse gas emissions have climbed 1.3 per cent to their highest levels in eight years, although Prime Minister Scott Morrison says the country will meet its Paris emissions reduction target.
Figures released on Friday showed Australia wasn't on track to meet its 2030 emissions target it will use an accounting trick to play catch-up.
The United Nations Emissions Gap Report published in November also showed Australia was not on track to meet its Paris target.
"There has been no improvement in Australia's climate policy since 2017 and emission levels for 2030 are projected to be well above the NDC (nationally determined contributions) target," the report noted.
"The latest projection published by the Government shows that emissions would remain at high levels rather than reducing in line with the 2030 target."
This week Mr Harwin tried to get state and territory energy ministers across Australia to discuss putting a roadmap towards net zero emissions by 2050 into a national energy policy at a meeting in Adelaide.
But Federal Energy Minister Angus Taylor refused to add it to the Council of Australian Governments agenda.
"We should be talking about getting prices down, keeping the lights on, making sure we're keeping manufacturers in business … not talking about higher targets when we know we're doing well," Mr Taylor said.
"It's time that those in those Labor states and others who are arguing for these crazy targets, reckless targets, get back to reality, talk to some real people, and get on with the job of doing the real work."
Labor has said it would not support new coal projects and has a 45 per cent emissions reduction target by 2030 and 50 per cent renewable energy target.
It looks like it will be up to the Australian people to decide what they want.