Combustion of biomass, peat, coal, oil and natural gas releases CO₂. Draining peat and forest fires increase carbon flux to the atmosphere.
There were widespread and intense wildfires in Southeast Australia during the summer season from November 2019 to January 2020. Estimates have been made of carbon dioxide emissions from these fires based on satellite monitoring data. The bar chart shows estimates made by five different research programmes: GFED, GFAS, QFED, FEER and FINN.
The table shows other statistics for comparison.
2019-2020 constrained by satellite. Nature (597), pp. 366-369. https://doi.org/10.1038/s41586-021-03712-y.]
The highest estimate of emitted from wildfires in Southeast Australia between November 2019 and January 2020 is 820 Tg , from the FEER research programme. State the lowest estimate.
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Using the data in the table, comment on the magnitude of the wildfires in Southeast Australia from November 2019 to January 2020.
In addition to carbon dioxide, carbon monoxide and other gases, the wildfires emitted smoke. Smoke is an aerosol of solid particles and liquid droplets suspended in air. The complex mixture of chemicals in this aerosol includes black carbon (soot) and compounds of nitrogen, phosphorus and iron. This aerosol absorbs light, allowing its optical density and movement to be assessed by satellite monitoring.
Much of the smoke from the wildfires in Southeast Australia in 2019-2020 was carried eastwards across the South Pacific Ocean. The study area shown in the map was affected by the smoke.
Australian wildfires. Nature (597), pp. 370-375. https://doi.org/10.1038/s41586-021-03805-8.]
The graph shows the optical density of the air and the chlorophyll concentrations of the water in this study area. The concentration of chlorophyll is proportional to the density of phytoplankton (photosynthetic bacteria and algae) in the water.
Daily measures of aerosol optical density (AOD)
8-day mean chlorophyll concentration in 2019-2020
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