The ferocity, reach and duration of fires that have devastated Australian communities, bush and rural landscapes this summer should not just sound the alarm for a climate emergency, because the situation is much more serious.

And Australia is "ground zero" for what is in reality a "climate crisis".

That's the stark warning Professor Mark Howden will give during his keynote address at the annual Climate Update at The Australian National University (ANU) on Wednesday. He and other speakers will also outline ways humanity can prevent the worst scenarios from occurring, and find solutions for surviving and thriving in a hotter world.

"There's been much commentary that we're facing a climate emergency, but I call it a climate crisis," said Professor Howden, Director of the ANU Climate Change Institute.

"An emergency is an unexpected situation requiring immediate action. However, the situation we find ourselves in has been entirely predictable and the ongoing impacts of climate change and need for informed and just responses will last for centuries.

"Many of the solutions we need are available, affordable and scalable, but they usually need a supportive policy environment to help them get adopted. The urgency of effective action is growing by the day.

"We have understood the causes of climate change, and we've been warned about its impacts for decades. As we've seen this summer, the impacts are now impossible to ignore."

Last year was Australia's hottest and driest on record, with the hottest day and hottest December, Professor Howden said.

"All of the fires, smoke, heat stress, floods and other climate disruptions we have experienced in the last year have occurred at just one degree Celsius above pre-Industrial global temperatures, Professor Howden said.

"The world could warm by as much as five degrees Celsius by the end of the century, if we continue the current trend of increasing our carbon emissions globally. This will have catastrophic effects on many of the things we value."

In a constantly changing environment such as this, there's no such thing as a 'new normal', Professor Howden said. 

"We have to be prepared for conditions to continue to change in unexpected ways."

Professor Howden said Australia and the rest of the world need to reach net zero emissions by 2050, to meet the Paris target of limiting global heating to well-below two degrees Celsius.

"If we start working towards this target now, it will reduce the costs, risks and challenges. If we put it off then the costs and risks will increasingly be borne by future generations," he said.

"Australia is at ground zero for this very visible climate crisis, but there's still hope. This is an opportunity for us to emerge as a global leader on this challenge.

"By developing new, low-emission industries and effectively adapting to ongoing climate changes, Australia could address climate change and turbo-charge the economy."

Associate Professor Carolyn Hendriks, from the ANU Crawford School of Public Policy, will talk at the Climate Update about inspiring and practical action on climate change by communities.

"Different groups and communities are responding to climate change in incredibly innovative ways," she said.  

"Many of these grassroots initiatives involve citizens self-organising to address a particular climate challenge in practical ways.

"They are establishing community energy farms, creating low-emission food cooperatives, assembling care packages for victims of climate disasters and rescuing and nursing wildlife from bushfire-affected areas. 

"These positive examples offer important lessons in how to respond collectively, practically and nimbly to climate challenges. Any government serious about working with communities on climate change needs to find constructive ways to enable and empower these community champions."

ANU Climate Update 2020 will bring together experts on climate science, disaster relief, health, social psychology and community engagement.