How is tree cover change calculated?

Tree cover change is calculated using data on woody cover from the National Forest and Sparse Woody dataset. The data are an annual time series in which 25 m grid cells are classified as either non-woody, sparse woody (sub-forest woody cover where crown cover is between 5-19%) or forest (woody vegetation ≥2 m tall with crown cover >20%). The phrase “tree cover” is used here to refer to areas with sparse woody or forest cover.

The Explorer calculates the percentages of forest, sparse woody and non-woody pixels in the carbon estimation areas (CEAs) (or project area where CEA data have not been released) for each year from the year the project was registered. Simple linear models are fit separately to the time-series of the forest and sparse woody percentages, with the percentage of each cover class as the response variable and year as the only independent variable. The slope of those relationships are used to classify cover trends inside the CEAs (or project area), provided there are at least three data points in the time series. Projects without three data points receive a “Not enough data” badge.

Projects are given an “Increased” trend badge if the slope of either of the fits for forest or sparse cover is greater than0.25% per year, provided the slope for the fit to the other woody cover class(i.e. sparse if the forest fit has a positive slope >0.25%) is greater than-0.05% per year.

Projects that do not qualify for an “Increased” trend badge receive a “Negligible” trend badge if the sum of the slopes from the linear models fit to the sparse and forest cover are greater than -0.25% per year. All other projects receive a ‘Decreased” trend badge.

The Timeseries tab provides graphs of the data for the three cover classes inside the CEAs (or project area), including the period from 1988 to project registration.

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Carbon Integrity Explorer

The Carbon Integrity Explorer provides information about carbon offsets projects registered under the Australian Government’s carbon offset scheme. 

Registered projects can generate Australian carbon credit units (ACCUs). Each ACCU is supposed to represent 1 tonne of real and additional abatement of greenhouse gas emissions. 

The Carbon Integrity Explorer uses government datasets to provide indicative information on whether projects are likely to be generating real and additional abatement.   

The information contained in the Explorer is indicative only and should not be relied upon as a definitive measure of the extent to which projects have, or are likely to, generate real and additional abatement. The Explorer does not:·  

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The Centre for Environment and Integrity Pty Ltd does not suggest or imply that any proponent of any project has done anything unlawful or unethical or that ACCUs issued to any project are not legitimate or valid. The indicative risk rating is an indicative measure of the abatement risk associated with relevant projects and nothing else. 

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