We start with the devastating floods in Brazil. More than 10,000 people have been rescued from floods in the Southern state of Rio Grande do Sul, but conditions are deteriorating. Close to 60 people have died, with 70 others missing. Entire communities have been ordered to evacuate after the river flowing through the state capital, Porto Alegre, burst its banks. Two people were killed in an explosion at a petrol station where emergency vehicles were being refueled. One dam has collapsed and others are at risk of failing with more rain forecast. Rescuers broke through the roof of a house to rescue a mother and her baby who were stranded in the floodwaters. The extreme weather has been caused by a rare combination of hotter than average temperatures, high high humidity and strong winds. Professor Chris Turne is an Earth scientist and Pro Vice Chancellor of Research at the University of Technology in Sydney. I've been talking to him about the impact of the flooding.

It's a tragic situation. This is actually the major flooding for these poor people in Southern Brazil that suffered from over last year. And this one's the worst for 80 years. But it's very much falling into a pattern now, as you say, a combination of absolutely horrific conditions combining to create this extreme event.

And what about people always talk about the El Niño, don't they? And how much is it down to that? And how much of it is down to global warming? What's your assessment?

Well, it's those two reasons, to be honest, Lucy. I mean, the first one is the El Niño. People might be familiar It's a warmer tropical Pacific Ocean. It's one of the biggest causes of climate variability in the planet. And it's basically shifting the wind planet, the wind belts at the moment. It's something that just starts to ease off, but this is the last arrive by the looks of it. It's basically shifting the rains to the south. People might have remembered the awful drought the Amazon suffered from. But in the south, it causes flooding. But on top of this, you're absolutely right, it's global heating. It's basic physics. We're putting so much carbon pollution to the air is adding around four Hiroshima bombs of energy to the atmosphere every second. And that's every second. And because the hotter air is first year air, it can hold more water. And so that's got to go somewhere. And unfortunately, we're going to get more of these extreme events, and they're going to be dropped on people around the world, causing these devastating impacts.

This does seem particularly bad in terms of the dams that are breaking. That just shows the force of the floodwaters, doesn't it? In terms of the region's readiness for these extreme weather events, what do you think? Are they going to need a radical overhaul of the whole infrastructure?

Very much so, Lucy. I think this is something we're seeing around the world now. We're having to build more resilience into our communities, into the way we live. We can't keep concreting over everything. You'll hear a lot of people talking about sponginess of cities and landscapes where we can absorb that moisture when it's wet and then give it out, release it when it's dry. But it's something we're going to see a lot more of. People might be aware the tropical Atlantic Ocean is a lot hotter than normal at the moment. That doesn't bode well for the hurricane season in the US and the Caribbean. We're going to have to do a lot more planning It's not the new norm because this is going to get worse. We're going to have to build that resilience into our communities, but at the same time, get that carbon down. But the good news is we can do it, but we've got to stop talking about this. Otherwise, Lisa, you and I are going to be having lots more of these interviews to use and chats, and we're going to keep seeing the same thing and getting worse.

So let's get on with it. I suppose the problem is also a radical overhaul of any infrastructure project needs a huge amount of money invested in it, doesn't it? And whether there's the will or the ability to do so.

Well, that is true. But of course, they cost an awful lot, not just financially, but human damage as well to the environment and our society, the tragic loss of life by not doing anything. And time and time again, it's far cheaper and better value to build that infrastructure now, but wait for the effects and then try and build back. And we've got to build back better as well. So unfortunately, we don't have any choice. We just got to get on with it. Governments, communities, industry, we're all learning together. We've got to help each other and get on with it.

Professor Chris Turne in Sydney.