Support materials only that illustrate some possible contexts for exploring Science as a Human Endeavour concepts in relation to Science Understanding content.
A range of evidence has been put forward by organisations such as the Australian Academy of Science and NASA in support of recent climate change occurring as a result of human activities (ACSES092). Remote sensing technologies and ice core analysis have provided data which is interpreted using climate models and computer simulations (ACSES091). Changes in near-surface air temperatures indicate that temperatures have increased in recent decades and are continuing to do so at an increasing rate. These data are corroborated by satellite observations of Earth’s surface and lower atmosphere temperatures, and measurements of the heat absorbed by the oceans. In addition, data indicate widespread melting of mountain glaciers and ice caps, retreat of ice sheets, sea level rise, increases in average water vapour content in the atmosphere and a shift in weather systems. Analysis of gas concentrations in the atmosphere and ice cores indicates that greenhouse gas levels have increased as a result of emissions from human activities over the twentieth century, and the majority of scientists believe that these atmospheric changes are linked to global temperature increases. Although there is disagreement about the magnitude of human-induced climate change, and some scientists contend that it has no significant role, most agree that these data indicate human activity is responsible for the majority of measured global warming (ACSES092).
Long range climate predictions are derived from computer models and geological analogues. Computer models incorporate a range of factors, and are tested by their ability to simulate present climate at global and continental scales (ACSES091). Analogues from geological time and recent centuries are used to study how the climate has responded to increased greenhouse gases in the past. Both approaches indicate that, in the absence of changes in any other factors, a continued increase in greenhouse gas concentrations should result in continued global warming and associated climatic changes. Predictions at a regional scale are less reliable than global predictions, owing to changes in atmospheric circulation and other regional factors, but it is likely that changes in surface and ocean temperature will lead to changes in the distribution of some species of plants and animals, with flow on effects for ecosystems (ACSES097). The United Nations Kyoto Protocol and the establishment of the Intergovernmental Panel on Climate Change aim to secure global commitment to a significant reduction in greenhouse gas emissions over the next decades, with the aim of significantly reducing long-term global warming (ACSES096).
Climate change science involves a range of uncertainties, which mean that the scientific community cannot predict future warming precisely, or detail exactly how climate change will affect particular regions. Models improve as the scientific community collects, shares and analyses more data, but even though models can be improved, they will always struggle to make reliable predictions for systems in which small changes can have large effects (ACSES095). However, although scientific models cannot predict the exact trajectory of change, they do provide significant evidence that climate change is occurring and that future global warming is likely. Decisions about actions to mitigate this effect depend on the perception of risk by individuals, communities, governments and international agencies and reflect their social, economic and ethical values (ACSES093).