Thank you for joining me today on this discussion around climate change and its importance to Australia and to the world. What I want to talk about now is what's happened globally in terms of global average temperature variations of the temperatures from 1850 right up to 2019. And what it shows is temperature variations are anomalies relative to that baseline. And what we also see is shown on here, global average temperatures have risen now by more than one degree, about 1.1 degrees relative to pre-industrial levels. And globally, we look and hear about global warming, which is the average of temperatures in the ocean, at the ocean surface and over the land. We know that essentially land makes up about one-third of the surface area of the globe, even if we're including Antarctica. But when we talk about global average temperatures, most people do not live on the surface of the ocean. What we should really be talking about in terms of climate change is the global land average temperature. That's what's shown here in these graphs. And the increases from essentially minus 0.5 degrees Celsius up to more than 1, nearly 1.3 degrees Celsius. In other words, a warming of 1.8 degrees, land average temperature. The conclusion from this is that since the pre-industrial period, the warming of land, average overall land surfaces is about double. And if we look at Australian temperature increases, the pattern of change in time is a little bit later or slower than the global average warming. In Australia, we did not get any pronounced warming until after 1950. And then there's been a very rapid warming of more than 1.5 degrees from about here on this scale minus 0.5 degrees to above one. In other words, a warming of about 1.5 or 1.6 degrees in only the last 70 years. Australia is surrounded by lots of oceans. And actually the oceans have warmed up more slowly and taken, particularly in the southern ocean. It's very big. And it has lots of deep mixing. So particularly the southern ocean has warmed more slowly than the tropical oceans and more slowly than the mid-latitude oceans in the northern hemisphere, just because it's so big, well circulated by the currents traveling around Antarctica, which are essentially mixing as well as the deep ocean circulation. So the southern ocean has warmed less quickly than most other oceans in the world. What I'm going to do now is show an animation of the two different types of climate models with high emissions and lower emissions. What you see when we look at these animations is time varying year by year. And here is 2018 and 2019. The observed temperatures, remember I said, was a global warming of about 1.1 degree relative to pre-industrial. These are temperatures relative to pre-industrial. 2018, it says 1 degree in the lower emission scenario, 1.3 degrees in the high emission scenarios, and the differences here are just year to year variability. If we run it a little bit, you'll see that in a few years' time, you can actually have the lower emission scenario here in 2024 and this simulation showing great warming than the higher emission scenario. Natural year to year variability dominates the temperature changes from one year to the next until we get substantially higher emissions. Let's run it on a bit further and I'm going to let it proceed until we end up with a period like 2050. It's only after 2050 that the increases in greenhouse gas emissions start to dominate the warming and we get significantly higher warming in the higher emission scenario than the lower emission scenario. In this we can also see that actually the patterns of warming are remarkably similar in the two sets of simulations, much more warming over land than over the oceans and much more warming at high latitudes, more warming in the inland areas than on the coastal areas. So it's important to think about these patterns when we're looking at the impacts of climate change and the largest warming is over the Arctic because the Arctic Ocean is cool, by sunlight being reflected from the sea ice. And if the sea ice disappears completely there will be much more warming and that's what we expect by 2050. So let's go to the end. The 2100 simulation for the higher emission scenarios shows warming across essentially all of the land masses which is greater than 6 degrees, greater than 6 degrees over Australia in the Arctic it showing warming of 10 degrees or higher. The lower emission scenarios show some Arctic warming of the order of 6 degrees but fortunately when we look at Australia in this lower emission scenario the warming is actually only around 3 to 4 degrees. So that's much better than 6 degrees but it is still substantial. This is a summary graphic. 2015 to 2019 was the warmest 5 year period, 1.1 degrees above pre-industrial temperatures. The climate impacts are hitting sooner and harder. Unfortunately despite commitments to limit global warming we've had a 2% annual growth in carbon dioxide emissions from fossil fuels over the last 10 years. We had a record high emissions in 2019 and emissions are not expected to peak until 2030. What do we need to do to limit global warming to 2 degrees? This is actually virtually impossible to limit global warming to only 1.5 degrees. The best assessment is if we wish to limit global warming to 2 degrees or lower we need to triple our global commitments to emission reductions by 2030. Australia's commitment is 25% emission reduction with no commitment to reduce emissions by 50% or to go to zero emissions. If we want to triple emissions that means 75% emission reduction by 2030 from where we are now which is 16%. So that means in Australia 5 to 6% emission reductions every year for the next 10 years. Together with continued growth in the economy because we need the economy to provide all the employment activities that we need as well. That's a massive increase. And it's a massive increase in all developed countries around the world but the UN Framework Convention on Climate Change has this commitment that says developed countries should take the lead in combating climate change. Australia signed on to the UN Framework Convention. Australia should be accepting that Australia should be taking the lead in combating climate change. Key messages. The human influence on the climate system was clear in 2007 and it's still clear. The more we emit greenhouse gases the more global warming there'll be and the more will be the risk of severe and irreversible impacts. And we can build a more sustainable, prosperous future. But we have to make choices and the choices we have to make are between the world on the left for which global warming is limited to roughly 2 to 2.5 degrees with substantial ongoing mitigation and zero net emissions globally by 2050. Or the world on the right for which global average temperatures are of the order of 6 degrees and global land average temperatures are of the order of 10 degrees. That is a very different planet. No humans have lived on a planet like that ever. Humans haven't actually lived on a planet like that even on the left hand world. But on the right hand side the planet is very, very different. Society will very likely be destroyed. What I see around climate change are the massive positive impacts that are happening associated with, for instance, young people and the school's strike for climate and young people getting engaged in worrying about their future with climate change. And then secondly, the massive opportunities that are happened with the dramatic decline in prices for solar PV cells and wind power. It is now cheaper to power Australia from solar PV and wind power than it is to develop a new coal-fired power station. And that is the best solution is when price and science combine together to say these are things are possible. And that is why I think I still can have a positive attitude. Things will get worse and we need to address those through adaptation. But we now have the opportunities to rapidly reduce global emissions and transition to a zero carbon economy. And that is what is important for Australian society and global society.