Thursday, 30 January 2020

Australia's 2019-20 bushfire season expected to increase total global atmospheric greenhouse gases by est. 2 per cent this year


According to NOAA Climate.govThe global average atmospheric carbon dioxide in 2018 was 407.4 parts per million (ppm for short), with a range of uncertainty of plus or minus 0.1 ppm. Carbon dioxide levels today are higher than at any point in at least the past 800,000 years.

With the ability of Australia's east coast forests to act as carbon sinks severely impacted by bushfires and air pollutants released by these fires to date circumnavigating the earth, it was to be expected that the amount of carbon dioxide parts per million in the atmosphere will rise sharply in 2020.

UK Met Office, media release, 24 January 2020:

A forecast of the atmospheric concentration of carbon-dioxide shows that 2020 will witness one of the largest annual rises in concentration since measurements began at Mauna Loa, in Hawaii, 1958.

During the year the atmospheric concentration of CO₂ is expected to peak above 417 parts per million in May, while the average for the year is forecast to be 414.2 ± 0.6ppm. This annual average represents a 2.74 ± 0.57 ppm rise on the average for 2019. While human-caused emissions cause the CO₂ rise in concentration, impacts of weather patterns on global ecosystems are predicted to increase the rise by 10% this year. Emissions from the recent Australian bushfires contribute up to one-fifth of this increase.

Professor Richard Betts MBE, of the Met Office Hadley Centre and University of Exeter, said: “Although the series of annual levels of CO₂ have always seen a year-on-year increase since 1958, driven by fossil fuel burning and deforestation, the rate of rise isn’t perfectly even because there are fluctuations in the response of ecosystem carbon sinks, especially tropical forests. Overall these are expected to be weaker than normal for a second year running.”

Weather patterns linked to year-by-year swings in Pacific Ocean temperatures are known to affect the uptake of carbon-dioxide by land ecosystems. In years with a warmer tropical Pacific, many regions become warmer and drier, which limits the ability of plants to grow and absorb CO₂ and increases the risk of wildfires which release further emissions. Along with other weather patterns and human-induced climate change, this has contributed to the recent hot, dry weather in Australia, which played a key role in the severity of the bushfires.

Professor Betts added: “The success of our previous forecasts has shown that the year-to-year variability in the rate of rise of CO₂ in the atmosphere is affected more by the strength of ecosystem carbon sinks and sources than year-to-year changes in human-induced emissions. Nevertheless, the anthropogenic emissions are still the overall driver of the long-term rise in concentrations.”

The CO₂ concentrations at Mauna Loa are measured by the Scripps Institution for Oceanography at UC San Diego and the National Oceanographic and Atmospheric Administration (NOAA). Fire emissions are monitored by the Global Fire Emissions Database (GFED).

The 2020 CO₂ forecast is available here.

As far as I can tell, it is likely that before 2020 draws to an end the atmosphere above the Australian land mass and coastal waters will probably contain at least est. 406.138 to 411 parts per million of carbon dioxide.

A carbon dioxide concentration of 400 parts per million is considered unsafe - a danger warning - and Morrison Government denialist-based climate change policy is making sure that we are now well and truly exceeding that figure.

The average surface temperatures over the Australian continent and its surrounding oceans have increased by nearly 1°C since the beginning of the 20th century.

This global rise saw land surface temperature in the NSW Northern rivers region rise by somewhere between 1°C and 1.4°C by 2014, with most of that warming occurring since 1950.

How hot will this region become in 2020?

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