Issue: Contributions and pressures between the land and the atmosphere - Climate

This is an issue under the Land theme of the Data Reporting System.

Why we need to know about this issue

Release of carbon into the atmosphere from vegetation and other life forms, and from the fossilized life of earlier epochs, could lead to long-term changes of climate through the ‘greenhouse effect’, as carbon dioxide and other greenhouse gases trap excess heat in the atmosphere. The problem can be compounded by the absence of sufficient vegetation to act as carbon sinks to re-absorb the atmospheric carbon.

Changes to climate can in turn affect the land and its life through changes to patterns of drought, rainfall and flood, wind, fire and frost.

Indicators

  • LD-05 Terrestrial carbon loss rate and rate of land carbon sequestration 
    When terrestrial carbon is released into the atmosphere as carbon dioxide, either through burning, natural decay or grazing, it can contribute to changing atmospheric composition and ultimately to climate change. Rates of carbon loss and sequestration give an indication of the volumes of terrestrial carbon that are being released as atmospheric carbon and preserved as terrestrial carbon.
  • LD-24 Severe drought and wildfire correlation 
    The indicator would plot, temporally and spatially, positively and/or negatively, the correlation between severe drought and wildfire.
    Altered fire regimes are a significant pressure on the land and its biodiversity that may result from changes in climate, particularly changed drought patterns. In the shorter term, extended periods of drought or more frequent drought will increase fire risk with hotter, faster fires because the land cover is present but dry. In the longer term, as vegetation disappears altogether, the fire risk is likely to decline because there is nothing to burn.
    Ideally the indicator would also correlate location of fire and drought and control for other land cover changes or changes to the management of native vegetation.
  • A-01 Annual variation in the Southern Oscillation Index 
    A number of studies indicate that the El Niño-Southern Oscillation (ENSO) explains 30 - 40% of the year-to-year variability of Australia’s climate, particularly rainfall. The Southern Oscillation Index (SOI) is a well-established measure of this phenomenon. El Niño events are associated with below-normal rainfall and often drought over much of northern and eastern Australia. They generally occur every two to seven years and are generally followed by La Niña events, which are associated with higher rainfall. Changes in the timing of these events may be indicative of longer term changes in climate which may have significant impacts on the land.
  • A-02 Rainfall trends - annual mean rainfall 
    Australia is the driest inhabited continent on earth. Its interior has one of the lowest rainfalls in the world and about three-quarters of the land is arid or semi-arid. Rainfall trends are important from an environmental and an economic perspective. For thousands of years, Australia has experienced strong year-to-year variations in rainfall. These natural variations and any more extreme variations or changes in the normal scope of variation that may result from anthropogenic climate change are important indicators for the pressure of this change on the land.
  • A-03 Rainfall extremes - inter-annual variations in annual extreme rainfall 
    Australia is the driest inhabited continent on earth. Its interior has one of the lowest rainfalls in the world and about three-quarters of the land is arid or semi-arid. Rainfall trends are important from an environmental and an economic perspective. For thousands of years, Australia has experienced strong year-to-year variations in rainfall. These natural variations and any more extreme variations or changes in the normal scope of variation that may result from anthropogenic climate change are important indicators for the pressure of this change on the land.
  • A-04 Temperature trends - annual mean temperature anomalies 
    Trends in temperatures are an indicator of climate variability and change that in turn will have an impact on the land.
  • A-05 Temperature extremes - percentage area of extreme annual mean temperatures 
    Trends in temperatures and their spatial distribution are an indicator of climate variability and change, which in turn have an impact on the land.
  • A-41 Greenhouse - climate change projections 
    Climate change projections can assist in the analysis of climatic pressures and climate driven changes to the land and terrestrial biodiversity.
  • BD-11 Area burnt by frequency, intensity and season of burning 
    Changes in area showing up as burnt at various points in time is a direct indicator of changes in the extent of fire occurrence, and provides essential data for determining any correlation between climate change and changing fire regimes.
  • BD-15 Examples of impacts of climate variability on selected species, habitats or ecosystems 
    As there is no continent-wide method of measuring changes that can be directly attributed to climate change across all species and habitats, examples of changes that appear to be directly attributable to this cause is at present the only useful indicator of the pressure of climate change on terrestrial biodiversity.
  • AAT-12 Changes in colonies of plants on Heard Island 
    Understanding the coverage and type of vegetation on the non ice area of Heard Island provides insight into the extent of glacial retreat as a result of climate change which may have implications for biodiversity on the Australian mainland and globally.
  • AAT-14 Ice sheet mass balance and sea ice extent 
    The changes in ice sheets, sea ice and fast ice may be indicators of climate change. In addition, the Antarctic ice sheet and sea ice plays a major role in global climate through its influence on heat exchange between ocean and atmosphere, it assists the formation of Antarctic bottom water which sinks to the depths of the ocean subsequently driving global ocean circulation. This indicator therefore had implications for the impacts of climate change on the Australian continent and globally.
  • AAT-15 Glacier movement 
    Heard Island glaciers have a relatively small ice volume, so the contribution to sea-level rise through glacial melt is not a concern. However, the unique climate signal that is coming from this predominantly oceanic region is of vital importance. It indicates that the change observed elsewhere in Southern Hemisphere mid-latitudes - in New Zealand, Patagonia, Kergeulen Island, South Georgia and Bouvet Island - is widespread.
  • A-45 Greenhouse - agricultural sector carbon dioxide equivalent emissions 
    Greenhouse gas emissions from agricultural land use are a significant contributor to Australia’s total greenhouse emissions. Global greenhouse emissions are considered to be contributing to global warming.

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