 My name is Dr Christine Hosking. I work at the University of Queensland in the Global Change Institute. And my research interests are around the impacts of climate change on wildlife, ecosystems and food security. So my research into koalas started several years ago when I was interested in whether climate change might be affecting koalas, particularly into the future under future climate change projections. So koalas have been in Australia for at least 30 million years according to the fossil records, so for my PhD research I felt it was important to understand the past before starting to look to the future under climate change. Australia has had many different climates over the millennia and the fossil records were fascinating. We've had many different species and genera of koala and they've been very widely distributed. They've been living throughout central Australia at Lake Air which is now desert western Australia. All sorts of areas far north, Queensland, areas where they no longer occur. So this little guy is actually the last member of a once far more diverse family tree. So this species, phascularctus sonaris, is actually the only last living species of koala. So it's terribly important that we preserve them because once this species of koala is gone, they're all gone forever. And then I did some modelling initially at the last glacial maximum about 18,000 years ago to discover I wonder where koalas might have been under a different climatic situation and then it was much colder and much drier. And I found that koalas would have contracted to a very small area in southeast Queensland, northern New South Wales. That would have been certainly their core range. And then of course about 15 million years ago when Australia started to dry out and eucalypt trees that they now each became more predominant through the landscape, they expanded outwards in their range again. So that was sort of the background for my research. I thought a bit like climate change modelling. You need to understand the past to really understand the future properly. So that was the first thing I did and then from there I developed climate projections for the range of koalas now and what future climate predictions might mean to where they can occur. And I also modelled their food trees. I chose five of their favourite food trees from throughout the current range of the koala which is Queensland, New South Wales, Australian Capital Territory, Victoria and South Australia. So I developed models for some of their key food tree species and had a look at where climate change might also affect the distribution of their food resources as well as the koalas themselves. Koalas now are unlike in those past millennia when Australia was actually a much better vegetated warmer and wetter climate and in Central Australia, Lake Air used to be covered in forest and there are many koala fossils in there for instance in Central Australia, but of course it dried out. So now koalas tend to occur mostly along the eastern Australian coastline. They have always occurred in land as well but this is where climate change impacts according to my modelling are really going to be felt. So what's happening is the koalas range is contracting from the inland more arid western zones particularly in Queensland and New South Wales, eastwards and this is where we have a real problem where east meets west because of course the eastern coastline is where most Australians live and where the development and urbanisation is occurring. So there's a combination of threats now acting synergistically on koalas. Climate change is very much pushing koalas eastwards towards urbanising centres. So what we're getting almost is a real impact from increased weather extremes to the west of their range. So long, long periods of drought and heat wave and the koala just can't thermoregulate adequately but the trees are also being affected by those droughts and heat waves. So the trees are drying out so the koala is not getting the nutrition that they intend because of course that's what they're completely dependent on. They have a very limited diet and then of course, so their food resource is getting affected as well but their climate envelope that I've modelled suggests that anything over about 37 degrees stresses them and of course now in Australia we're experiencing a week of days in the 40s so those prolonged extremes in climate are really affecting the koala. A 60% decline after a heat wave was documented in the Mulga lands of Queensland and then more recently there's been another 80% decline in the western regions. That's over a 10 year period during a 10 year drought so my predictions of these contractions are actually being validated by underground observations now. 80% is catastrophic, it's completely catastrophic and then in the urban strip we're experiencing similar declines of 60-70% from other impacts on the eastern edge and this is from dog attacks and car hits and just that loss and fragmentation of their habitat roads, rails and then predation so the koala is really getting hit from all directions now. So in heat waves and droughts the adaptation measures for koalas are not great, they're not a very mobile species so for instance if their climate envelope had 300km eastwards a koala can't just think I'll just hop over 300km so they're not that mobile a male may travel up to 20km maximum if he's leaving his home range and leaving his mother and wants to create his own territory but a female koala if she has adequate habitat will often only move 4 or 5km even smaller home range if the conditions are favourable for her so to expect a koala to move hundreds of kilometers under such rapid climate changes we're experiencing now is impossible so this is why we're getting real population crashes in those areas adaptation measures some adaptation measures that they do is they'll find trees that are more shady so sometimes a non food tree but if it's got a good canopy of shade they'll tend to go higher in the tree and seek shade but nonetheless they have their limitations so this thermal regulation will kick in and eventually they will just fall from the tree and not be able to cope and die of heat stress and dehydration another adaptation measure will they already adapt in a way by sleeping a lot through the day to try and stay cool and become more active at night but that's about it under different emissions scenarios I did most of my modelling on the business as usual scenario because as we are now aware that is actually where we are tracking so the business as usual is high population growth and everything high energy from fossil fuel requirements from people so I based most of my modelling on the worst case scenario because that is where we are now tracking as simple as that so those sort of drastic and as I said where research is being done those pessimistic scenarios appear to be eventuating with these population declines of 80 plus percent of koalas in the western edges of that range where the heat waves and droughts are particularly bad under a lesser if you wanted to go backwards to a kinder scenario say if by 2050 we have managed to stay below 2 degrees of warming for instance which appears unlikely at the moment if we did well for a start how many koalas will be left by 2050 that's a big question but the kinder of less extreme scenarios those effects would just be less pronounced so perhaps there would be a little more in the western areas of their range particularly habitat that might stay viable for koalas but the food trees are modelled are also going to be affected similarly so even if the koala manages to hang in some of these areas where it's going to be hotter and drier the question is will their food trees still be there as well so that's where the modelling work I did will hopefully help influence conservation planning decisions so if land managers want to look at an area for instance under the carbon farming initiative that the Australian Government is very actively pursuing at the moment looking at areas to rehabilitate so perhaps looking at areas that potentially could be set aside for carbon sequestration it would be nice to plant it for koalas planted out with their food trees and help guide them on which food trees are likely to be viable in those areas that they're looking at my projections into the future go from the current climate to 2030 and then 2050 and then 2070 so they're going out as far as 2070 and the mapping indicates very clearly these contractions eastwards that you can see if we look at the southern states where the koala is not federally listed as vulnerable at the moment because there appear to be abundant koalas in those states for all sorts of other reasons historical reasons in terms of koalas being culled for the fur trade back in the early 1900s so some koalas were put on islands down in Victoria and South Australia because they were literally being shot in the hundreds of thousands and they'd become virtually extinct on the mainland in the southern states so some koalas were put on islands but they have bred in big numbers and they did have suitable habitat so it became unsustainable for them to stay on the islands they've eaten themselves out of house and home so they're now being translocated back to the mainland but that is fraught with problems because on the mainland particularly in the southern states of Australia again the same problems are there habitat loss, fragmentation wildfires, bushfires which are catastrophic for koalas and in fact one area a few years ago in Victoria there was a bushland national park called Framingham and it had several hundred koalas living on it that had been translocated back from islands it was good habitat they were doing well and then a bushfire came through and took them all out and of course they had no issue dispersed too because it was an island on a mainland ocean of urbanisation and farmland so even down south although the federal government has not yet recognised that they are in deep trouble there as well there are many of the same threats climate change is also impacting down in the southern states of Australia very much with the increased bushfires increased heat waves my predictions don't specifically address bushfire risk but when you have the prolonged droughts and heat waves one consequence will be bushfires and in fact the black Saturday bushfires in Victoria several years ago we're a very good example of that Victoria experienced I think 5 or 6 days over 45 degrees and during that time on the internet people were posting what they thought were bizarre sightings of koalas wild koalas they didn't even know occurred in their area were coming in and taking water out of the dog's drinking bowl licking hunger thirstily out of a tap, out of a garden tap and other koalas literally lying beside a swimming pool nearly dead just trying to get to moisture and it was sort of a pretty spooky because a few days after all those photographs went up on the internet was almost if we'd listen to the koalas we might have seen what was happening because then the bushfires broke out several days after that so that was a classic example of the koalas showing us hey whether conditions are so extreme and so catastrophic we're all dying and bang black Saturday fires happened and of course many many koalas and other wildlife that Australian native wildlife that lives in the same habitat as koalas were completely destroyed in those fires so at the moment the future for koalas looks pretty grim this fellow's mother was killed by a dog we have to address controlling dogs in areas where in urban areas where koalas are still occurring we need to obviously mitigate our CO2 emissions and bring climate change under control and that's for many species of course not just koalas it's very difficult because in the eastern areas of Australia with so much urban development so many people living here it's very hard to know how an animal like this can possibly cohabitate with roads and cars and people and just loss of these leaves and he's very fussy he's evolved to be a real specialist on certain species of this leaf this obviously being one of them and when these trees go he has no way to adapt to that he'll get down off the tree he'll try and move and then get skittled maybe by car or taken by dog so the urban dilemma is a real issue the western dilemma at the moment due to climate change is a real issue my personal recommendations are to be proactively setting aside corridors large corridors for koalas and of course they need large areas of continual habitat at least 100 hectares and the more the better that connect without roads and urbanization being in the way and Australia is lucky if we move a little inland so if we look at there's a great dividing range and some areas of hinterland and hills that are lush and attract rainfall and are cooler that are often just to the west of the coastal strip and a lot of these areas are still very viable for koala and other wildlife conservation and I would love to see decision makers setting those aside and proactively conserving them for koalas wildlife and of course the ecosystem services all those things that keeping those ecosystems provide to human beings as well so the story of this particular koala here he is with a wildlife carer wildlife carers look after native animals that have been orphaned usually due to their mothers being killed by a car or a dog and they come into care from a very young age and simply would not survive on their own we don't know how many of them of course never get to carers and of course they just die where they are but guys like this one were lucky and got found because the mother was being radio tracked because she was living in an area which is being urbanized and developed so the koalas in there are being monitored to see the impacts of this new development on them so they found the mother and she had been dead for about 24 hours so there are some wonderful koala carers and other wildlife carers around Queensland and around Australia who take these animals in for basically they give their time and the expenses are out of their own pocket and they dedicate themselves to the job of bringing these animals up to a stage where they can be released hopefully into a good area of habitat so they are being given a second chance to start life basically so this koala is only a year old it's got quite a bit of maturing to do yet and he will be released hopefully into some good habitat and there are many koalas and other native animals in the hands of carers and I don't know how any of these animals would go without these wonderful wildlife carers there are some carers who band together and develop a group and have a website and they of course will always welcome donations from a formal structure set up for instance by the government to help them the local government in Queensland has recently released a round of funding applications specifically targeting wildlife carers so they can go to all the effort of applying for the money it's a bit of a shame that they have to do all that though with their time being so stretched many sleepless nights especially when this little one was younger and getting up in the night to feed him as well but at the moment that's really all they get is they can occasionally apply for some funding from an official source and get some money to help supplement what they do during the Black Saturday fires there was a lot of publicity surrounding the plight of the native wildlife and some people including myself managed to get the word and that's really through the social networks and the word got out that the carers were in desperate need because so many burnt and shard and injured animals were coming into care and the carers couldn't cope so people were donating their old sheets and blankets and towels and some cash but generally it's not a very formal structure the main challenges for koala carers are burnout it's very tiring and it's pretty thankless and it never ends sadly it never ends the steady stream of koalas like this one coming into care in fact we get a bit concerned when we'll see a certain geographic area where suddenly the koalas aren't coming into the wildlife hospitals and then being passed onto carers and that's pretty much usually a sign that the koalas are all gone from that area so you tend to get a peak of incidents from an area that might be suddenly being developed a lot or out west that could be a mine for instance has been built and so suddenly what used to be a country road is taking very large volumes of mining traffic so we also have cases of where koala populations have declined drastically from traffic increased traffic on a road that used to be fairly quiet so it can happen for different reasons away from the coast as well but sleepless nights carers have to put up with a lot of ongoing fatigue they're pretty much fatigued all the time so it really is for the love of it and knowing that you're giving these animals a second chance the carers often need caring and they often need a holiday and I don't think they take them very often carer groups tend to be quite loosely aggregated and quite broadly dispersed around the place some of the larger carer groups have formed websites someone can go on their website and express interest in becoming a carer they then have to go through a training process which is only a couple of workshops because you can't just think I love that cute furry thing I want to look after it in fact ignorance can be very dangerous so they must be trained properly and that can be organised through some of the larger carer organisations it would be lovely to have more volunteers as wildlife carers because there is a turnover because they do get exhausted or perhaps they'll have a family of their own or they may move for whatever reason so we always need more wildlife carers and there can never be enough wildlife carers it would be wonderful to see more people perhaps who love animals who love energy into domestic pets for instance it would be lovely if they express that love through native wildlife that's been here for millions of years and often like the koala occurs nowhere else on the planet one of the reasons why koalas are so fussy with leaf is because eucalyptus leaf has large amounts of toxins it's not at all palatable so a koala needs to seek out a tree that does have some nutrients such as nitrogen as well as the toxins and the reason they are so sleepy is because it takes pretty much all their energy to simply digest all the toxins in this leaf they tend to have trees that are their very favourites what I call their Swiss chocolate species and these vary regionally so down in Victoria it will be a different favourite chocolate to a tree further in up north in New South Wales or in Queensland in Queensland in the more western areas it might be River Red Gum they really favour and that tree grows along water courses and in drainage lines so it puts down deep roots and of course this is why that tree is also being impacted by climate change the rivers dry up and so on if we come out to the coast there are trees such as tallowoods eucalyptus microchorius in the Queensland area that they seems to be their very favourite and forest red gum if we move further south into Victoria Managum is a very popular tree and so there are some of the species that I did model to see how those trees would be also impacted by climate change and the results varied according to the tree species but a lot of the trees also do contract a lot eastwards back to those urban areas again often you'll see a koala at the bottom of a tree and he'll be sniffing and it's actually deciding whether that leaf might be good leaf and the nutrients and toxin balance comes of course from rainfall moisture and also from the soil so soil is a really important thing and that is one of the other issues that we tend to farm and develop areas that are on really good soil so that good soil happens to also be where the best food trees for the koalas are so they've also lost out there so now they're often forced into secondary what we call secondary habitat so it's not perfect trees the carer has sourced this leaf especially grown trees for koalas so this is why he's loving it so much but in general a koala you might see six trees in a very small area and you might think why are all the koalas just in that one tree and it's because that is the best tree in terms of that balance of nutrients and toxins and this is why it's a problem if they're in an island situation whether it's an ocean island or a mainland island why it's difficult because they'll all be gravitating to their best chocolate trees and they will ignore other trees so they will defoliate they will just literally overbrow certain trees are the best ones for them so in the old days of course before humans came along to Australia a couple of hundred years ago there was continuous habitat and a koala could meander around find the best trees the soil hadn't been degraded the best soils in the best areas with the best trees were available for them modelling at the last glacial maximum even though the koalas range probably did contract of course when the weather conditions improved the koala was able to simply expand his range again because we weren't in the way and that's what's changed now so I've done some modelling on the potential effects of future climate change on agriculture using several case study commodities in Australia and eastern Australia so looking at grazing and the widespread throughout the whole country and cropping and avocado production and I ran models projecting to 2035 based on a lot of interviews with farmers and industry to look at and extension offices so people experts in the field to determine what would be the best climatic and other environmental variables to put into my models so you know and avocados prefer certain climatic factors very important for avocado growing at certain times so you need to know what they are so after doing that and getting feedback saying they didn't really want to know about 2080 they'd prefer to know more in their foreseeable future was a bit more tangible for them I modelled these three commodities both under the current climate at 2025 and 2035 and the impacts are around at this time I used two different global climate models so one was a pessimistic business as usual model under that sort of scenario but you know predicting a hotter dry future the other model is predicted a warmer still hotter and dry but not as extreme so a bit warmer and wetter than the extreme because I thought for this industry it was important to show them a couple of options not just the real doomsday one and farmers are brilliant at climate change adaptation already I learned they have been doing adaptation measures for years improving their technology growing different types of crops even buying multiple properties so that if it's dry in one area their farm 50 kilometres away might have had rain so they cover their base all sorts of adaptation strategies they've been doing for many years so they have to be very sensitive to that not come in and say I've sat behind a computer and run models and I can tell you so with this range of scenarios and outcomes it still does appear under both climate models that I used that these three commodities will certainly be affected by climate change and that varies very much regionally though because particularly for rainfall the rainfall predictions are less reliable than the temperature predictions and they're very much more regionally spaced so whereas overall we know it's going to be warmer we don't know so much about rain some areas will be much drier some areas will get monsoonal rain still and they'll be okay so this all went into the model and as a result there was a lot of spatial variation in the predictions but overall I found a significant decline in all those three commodities under future climate change so hopefully this work will be a bit of a decision support tool for them so that they can look at perhaps this area, this northwestern part of our agricultural cropping zone for instance in northern Queensland is definitely going to be seriously affected by climate change but we can at least still focus our cropping in other regions which appear to be okay even under future climate change so again was just helping with decision support these models aren't silver bullets but overall the message was definitely substantial impacts from climate change so under business as usual avocado for instance will decline by 88% between now and at 2035 so it will become much more contracted on little coastal pockets than it is now down in Victoria there's an area called Sunrasia where according to both models it'll pretty much disappear from there which is a bit inland in Victoria and it'll really shrink down to the coast cropping will by between now 2035 will decline by I don't have the figures it's in excess of 50% under the pessimistic scenario and about 25% under even the kind of global climate model and grazing grazing will be not quite so impacted because it's so widely the models almost weren't as reliable for grazing because grazing is so widely it's all over Australia so it's a little bit harder for the model to tease things out of that but grazing will definitely shift and it'll contract in some areas some areas will improve where there is still rainfall predicted to occur it's all going to shift and in many places it's going to contract dramatically the interesting thing about going out and talking to farmers rather than just doing the modeling was to find out that they're already doing these adaptation measures and one example for instance is tomatoes used to grow in the Lockhear Valley west of Brisbane and they have disappeared the farmers aren't growing tomatoes at all they've moved down to the granite belt where it's cooler and wetter that's already happened in real time without us even knowing without the average person knowing so yeah it's going to have a big effect on farmers and many of them are already and a lot of them are already mixing their types of cropping and having a plan B crop because they're learning that plan A crop is actually failing now there is an argument with farming and cropping for instance that increasing CO2 helps plant growth but it's a little bit more complicated than that and although some crops will benefit from that it may be offset for instance by the fact that there's drought and no rain so it's a balance and flooding extreme weather events may well neutralise those benefits of increased CO2 models are only models and they're not silver bullets so they're not building in a lot of these subtle things like human adaptation improvement in technology and extreme events and so on but what we do know from the climate models is that these extreme events are going to happen more often and they are really already impacting all sorts of farming in Australia in a very big way I got into this area of research originally because I was actually talking to a person who runs a koala conservation organisation and I met her socially and we got talking and she said I would love to fund some research if you're thinking of doing a PhD I'd love to talk to you about funding but it hadn't necessarily been about koalas in the beginning there was going to be something to do with ecology and wildlife but I happened to meet this person and she heads a large koala conservation organisation so that's what steered me that way what's interesting me the most in terms of in my area of interest would have to be the impacts of human encroachment to native ecosystems and the bigger effect of what that means for ecosystem services that underpin our quality of life as humans so I suppose it interests me that to find out more about what we can do in the face of population growth climate change and an increasingly populated world we've managed to balance feeding the world and accommodating humans while still holding on to our precious ecosystems that are really fundamental to everything I think these days scientists are getting a lot better about communicating their science to the general public social media helps a lot publications like The Conversation that are freely available to everyone online and they're written by scientists more and more scientists are understanding that they've got to use those sorts of avenues now to reach the general public and I think scientists have to continue to talk with policy makers and government even if at times that's hard to keep pushing and trying to open those doors with koalas I've certainly had a lot of success communicating with government over the plight of the koala and it's been successful so it's encouraging and I think scientists just need to realise they have to talk in general language sometimes to communicate their messages people who don't accept the science of climate change are very challenging and require a lot of diplomacy and I think most people who like me who've tried to convince people who don't believe in climate change really don't get very far and my feeling is that it's almost more a case of some sort of positive reinforcement so to approach it differently rather than lecture people which really does alienate you almost instantly is to just talk about things around climate change like you live on the river and what a beautiful spot and it'd be nice to keep that water flowing wouldn't it be sad if we lose our koalas because of these wretched droughts so a more indirect approach can engage people rather than just saying I'm telling you this is how it is because that fails. I have seen arguments sometimes where critics have not wanted to acknowledge the science but have tried to say you're just making that all up because you want funding for your next round of research but certainly in my experience it's never about that it's about the love of what you're doing and the real your own inner values and beliefs that make you want to really passionate about informing the broader population about this problem or trying to solve a problem that you know really is important and meaningful and I think the funding is secondary and sometimes of course your institution will need funding to help support you to do that because research costs money and that's fine but I don't think it's a driving force I think it's all about answering really important questions that to you are meaningful and that's always the first priority. Humans are causing a rapid escalation in climate change through greenhouse gas emissions and through burning fossil fuels and we need our decision makers at the big end of town a bit like Obama and the Chinese leader recently did to really grab it and take real action it's like the Cirque du Soleil behind you at the moment this was the whole point of not having the koalas in it I think they're doing it out of the shot anyway out there