DR SARAH PERKINS-KIRKPATRICK, RESEARCH FELLOW, UNSW CLIMATE CHANGE RESEARCH CENTRE: I think this one, it's one of my favourites.

KERRY BREWSTER: Four climate scientists at different stages in their lives and careers reveal the burden of knowing what predicted climate changes will bring.

PROF. KATRIN MEISSNER, DIRECTOR, UNSW CLIMATE CHANGE RESEARCH CENTRE: I think for years I was really living in two different worlds. I was a scientist at work who was just objectively looking at numbers, and, um, then over years starting to be more and more worried about my own life, but I separated it completely from my private life.

I think that was a little bit of a self-protection.

'

'That doesn't really work that well anymore. In the past few years, I carry this knowledge with me wherever I am.

That looks beautiful, Kaitlin! That looks amazing. Look at this.

My name is Katrin Meissner, I'm the director of the Climate Change Research Centre of the University of New South Wales.

I have been working in this field for the last 20 years and I have been mapping lots of concerning trends in that time.

Many people do not really understand how big a threat climate change is to humanity.

The changes that we see right now are much faster than anything we have seen in the climate history and that concerns me because it means that ecosystems might not be able to adapt.

It's going to be dramatic. It's going to be very dramatic.

SARAH PERKINS-KIRKPATRICK: I think one day in the last heatwave I measured 45 degrees outside in the shade in our front patio, and it was 39 on the inside. I was sleeping with wet towels on my legs to keep cool.

I'm Sarah Perkins-Kirkpatrick and I'm a research fellow at the University of New South Wales and when I look at is heatwaves, so how they have changed, why they have changed, what their changes will be in the future, how we measure them and the role of climate change behind the heatwaves.

I had conversations with my husband as these heatwaves were occurring in summer, going, "Are we doing the right thing? Is it right to bring kids into this world?" with me knowing how bad it's going to be.

There is so much wrong with climate change and there are so many impacts that we're already looked into that I can't change, that no-one can really change. It's going to be bad and it's almost why would you inflict that on someone?

JUSTIN OOGERS, PHD STUDENT, UNIVERSITY OF MELBOURNE: Okay, so that's where it's going to go.

My name is Justin Oogers, I'm doing a PhD at the University of Melbourne just looking at urban micro climate as it is now and looking at how we can improve it into the future.

We need to be able to plan our cities better, we need to be able to design them better, keeping in mind what's coming, keeping in mind these temperatures that are getting into the 50s in Melbourne, and often I can't believe that I'm saying that, but the computer models, all the research is telling us, this is what's coming.

Yeah, it's tragic. Whenever I talk to my wife about heatwaves, she gets scared of them and unfortunately I can't really give her any good news.

I have been married for about five years. Yes, we want children, but we're quite concerned about it, even scared of it.

Our parents both want us to have children and there's lot of joy that comes with having children, but at the same time, knowing what's coming with climate change, we have actually just been putting it off.

PROFESSOR DAVE GRIGGS, DIRECTOR, MONASH SUSTAINABLE DEVELOPMENT INSTITUTE: You can say you don't believe in gravity but the apple is still going to hit you on the head. You can say you don't believe in climate change but it's not going to stop it getting it hotter.

I think Australia is the most vulnerable developed country in the world to climate change.

My name is Professor David Griggs, I work at the Monash Sustainable Institute at Monash University.

My background is as a climate scientist and atmospheric physicist. In the past I had been the head of the intergovernmental panel on climate change, science working group secretariat. I have been director of the Hadley Centre for Climate Change which is the UK government research centre into climate change and I've been the vice-chair of the World Climate Research Programme.

I think we're heading into a future with a considerably greater warming than two degrees and when the world doesn't do something about it, that brings a whole range of emotions into play.

I mean, depression is what is clearly something, you know, you get days when you're down because you just, what you know and what you can see coming is not good.

For people living in Australia, it means that a lot of people will suffer and a lot of people will die.

The problem is nobody's death certificate will say this person died of climate change. It will say they will die of heat stress, or cardiac arrest or they died in a bushfire.

SARAH PERKINS-KIRKPATRICK: Climate scientists are under a lot of scrutiny. We get ridiculed a lot by certain people for being alarmists, by going too much into detail. Where in actual fact we're actually probably reservists and are very conservative in our estimates and make sure we're so sure of the numbers before we actually get them out there.

I don't like to scare people, but the future is not looking very good.

DAVE GRIGGS: I'm fortunate in that I live in Melbourne at the moment and Melbourne is one of the more climate adapted cities in Australia.

If I was living in Darwin or Brisbane, I would be seriously thinking about moving.

One of the important things about climate change when you think of it in the context of sustainable development...

KERRY BREWSTER: Among climate scientists the conversation is turning to their personal plans.

DAVE GRIGGS: We'll talk about where we're planning to retire to or where we're planning to move to, how we're planning to, you know, safeguard our families from, in the future.

And the consensus seems to be Tasmania. Tassie because it's the furthest south, it's the coolest.

SARAH PERKINS-KIRKPATRICK: We have thrown up the idea, you know, the potential if the opportunity came up is moving to Canberra. It's a city, it's got good infrastructure, it's got good employment opportunities.

Yes, it gets warm there and yes, it's a dry climate but the temperature doesn't get as hot as Sydney. Their night-time temperatures are a lot cooler and you can cope with extreme heat much better if you got cooler night-time temperatures to sleep.

JUSTIN OOGERS: For me and my wife, anywhere, maybe forced to move further south, and I'm sure that there's a lot of other people that are probably thinking the same thing.

My grandpa decided to move down to the coolest part of Australia. He's living on a boat south of Hobart and he's trying to drag me down to Tasmania. He's saying, "The University of Tasmania is down here. Should come down here", and I have often said to him I'd think about it.

My wife, she is a lot more keen to do it.

KATRIN MEISSNER: I find it really hard to decide on one particular region saying this one is going to be safe and we are just going to lock this one in.

I don't think there will be any safe places. I am, the impacts are going to be big.

So my approach is to be as mobile, as flexible as possible to be able to adapt to whatever is going to happen. My children are bilingual and we're working on a third language.

Both children have three passports, and they actually have the freedom to be able to study and work even in the European Union, or in Canada or in Australia.

KERRY BREWSTER: After scoping New Zealand and Tasmania, Professor Griggs has settled on his native England as a climate change retreat.

DAVE GRIGGS: London is over here on the right-hand side. So we're down here in the south-west with Devon and Cornwall.

This is the house. Just a traditional old English farm house built around 1800. That's my vegetable patch so that's where I can grow my own food.

I have certainly taken a look at this and looked at the climate projections and said yeah, that's going to be good for the next sort of 100 years or so.

When, some new fact comes in that makes me fearful, I think, well, at least, you know, I have done what I can to protect my family.

I can't protect them from changes in the global economy. I can't protect them from, you know, mass migrations, I can't protect them from, you know, some of the impacts that they are going to be, no matter where I move to and no matter where I buy my house, but I can do what I can.