[Music plays and image shows a computerised image of a spinning globe. Text appears: Global Climate Models]
Narrator: Global climate models, which are based on the laws of physics, enable scientists to answer a range of questions about our climate.
[Image changes to show a graph]
Like, what happens as atmospheric greenhouse gas concentrations rise?
[Text appears on screen: Climate Change. Greenhouse Gas Emissions]
Emissions of greenhouse gases, such as carbon dioxide, are a major driver of climate change.
[Image changes to show a graph and text appears: Global Warming (°C)]
This graph shows global warming observed over the 20th Century.
[Text appears on graph: Observations; Only natural changes]
If only naturally occurring factors, such as variations in the earth’s orbit, solar fluctuations and volcanic eruptions are included, climate model simulations of global temperature cannot match the observations. Add the effect of increases in greenhouse gases to natural factors and the simulated warming agrees with observations.
[Text appears on graph: Observations; Natural Factors + Greenhouse Gases]
[Image changes to show an animation]
The extent to which we can restrict future emissions of greenhouse gases is unclear, so scientists explore possible future scenarios by running the models with different levels of carbon dioxide and other greenhouse gases. The output from each simulation provides projected changes for many aspects of climate, such as temperature, rainfall, and sea level]
[Text appears on animation: Temperature; Rainfall; Sea Level]
[Image changes to show a graph and text appears: 2090 Projections – Intermediate Emissions – Temperature Rise]
Australia is likely to warm in future. Higher emissions cause greater warming.
[Image changes to show a graph and text appears: 2090 Projections – Intermediate Emissions - Winter Rainfall Change]
Winter rainfall in southern Australia is likely to decline. Most of the country is likely to experience more extreme daily rainfall.
[Image changes to show a graph and text appears: Sea Level]
Sea levels are projected to increase at a faster rate than during the last century.
[Image changes to show various icons and text appears: Government; Insurance; Infrastructure; Shopping; Agriculture]
Climate projections are being incorporated into the planning processes of governments and business.
Climate projections are helping us prepare for a climate that will be different from what we have experienced in the past.
[CSIRO logo appears with text: Projecting Climate Change]
[Australian Government logo appears with text: An Australian Government Initiative | Inspiring Australia]
Projecting Future Climate change
Monitoring greenhouse gases at Cape Grim
Cape Grim, on Tasmania’s northwest coast, is one of only three World Meteorological Organization (WMO) global super-stations for the measurement of greenhouse gases.
This year, 2016, marks the 40th anniversary of the first greenhouse gas measurements at Cape Grim. CO2 (carbon dioxide) and CFC (chlorofluorocarbon, a potent synthetic greenhouse gas responsible for the ozone hole) measurements began in 1976 and later extended to cover all major greenhouse gases. Cape Grim’s location is unique in that its exposure to the weather systems coming across the Southern Ocean mean that about 40 per cent of the time atmospheric measurements are not influenced by local sources of pollution.
Cape Grim greenhouse gas data are freely available, and are widely used to quantify global, regional and Australian emissions of greenhouse gases. They have been used in hundreds of research papers on climate change and ozone depletion, which have been cited in all five Intergovernmental Panel on Climate Change (IPCC) international assessments of climate change and in all seven United Nations Environment Programme (UNEP)/WMO international assessments of ozone depletion. Cape Grim greenhouse gas data also provide independent verification of Australia’s National Greenhouse Gas Inventory, which reports Australia’s annual emissions to the United Nations Framework Convention on Climate Change. Cape Grim air is analysed in situ, but also in CSIRO’s GASLAB in Melbourne and in a number of laboratories around the world.
CSIRO commenced collection of the Cape Grim Air Archive in 1978; this long-running collection forms a critical component of the world’s background atmospheric air samples, underpinning extensive research on global and Australian emissions of greenhouse and ozone-depleting gases.Greenhouse gases