Climate Change Research at RSES
Introduction to climate change research
Understanding climate change is one of the most critical scientific goals of our time. This is a complex issue, highly political and will affect not only us but generations to come. Climate change can be separated into several components: quantifying and understanding how the Earth is currently changing (increasing global temperatures and sea levels, melting of ice caps), understanding the forces driving these changes (greenhouse gas emissions vs natural climate variation), predicting future climate scenarios and assessing the likelihood of their eventuality. The issues tackled at RSES using a wide diversity of methods including:
- determining past histories of climate change and sea level variations;
- understanding natural modes of climate variability;
- investigation of climate processes;
- assessing mass balance changes of polar ice sheets
- studying variations in Australia's water resources
Research topics
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Changes in mass can be detected from space-gravity missions and provide key information on how polar ice caps are responding to present-day temperature changes and how continental water resources are varying. Under a warming climate scenario, increased precipitation is predicted for low-latitude zones while mid-latitude regions such as southeastern Australia will become drier. |
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Radiocarbon is produced in the stratosphere by the collision of nitrogen atoms with thermal neutrons produced naturally by cosmic rays or artificially by atmospheric nuclear bomb testing. Atomic 14C is rapidly oxidized to 14CO2 in the atmosphere and enters plants and animals via photosynthesis and the food chain. When an organism dies the 14C decays back to Nitrogen 14. The half-life (the time it takes for half of the carbon-14 to decay) is 5730 years. After about 10 half-lives there is essentially no carbon-14 left in a sample. This results in a limit of this technique of 50-60,000 years, after which other radiometric techniques have to be used to age a sample. |
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The dynamics of the global ocean depends on the forcing from climate and the physical processes which occur in the ocean. Studies into Ocean Dynamics concentrate on determining the role of physical processes through both laboratory experiments and numerical modelling. Examples include flow through straits such as the Indonesian Throughflow, the East Australian Current and the Antarctic Circumpolar Current in the Southern Ocean. These studies ultimately feed into models of the earth's climate and ecosystem. |
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Cosmogenic nuclides (He-3, Be-10, Ne-21, Al-26, Cl-36) have emerged as the most significant new tool for dating landscape features, and form the basis for a rapidly growing and exciting new field of geochronology. Cosmogenic nuclides can be used to date glacial and volcanic landscapes, as well as meteorite craters, fault displacements, landslides and to determine erosion rates. |
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Ocean-atmosphere interactions in the tropical Indo-Pacific Warm Pool are fundamental drivers of the global meridional Hadley and zonal Walker circulations. Recent research indicates that changes in sea surface temperatures and atmospheric convection in this region play important roles in modulating global climate on interannual, decadal, millennial, and even glacial-interglacial time-scales. Knowing the natural bounds of past ocean-atmosphere variability in the Warm Pool region will enhance our ability to predict the climate in the future. |
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Sea level is a major key to understanding the climate system because it varies with the volume of the icecaps and thermal expansion of the oceans. Modelling historic sea levels holds the key to understanding present and future variations. Evidence from coral terraces at Huon Peninsula, Papua New Guinea show sea level rises of 9-16 m accompanied Heinrich events (30-65 ka). Present-day estimates from satellite altimetry show ~3 mm/yr increase while tide gauge records suggest an acceleration in the 20th Century. |