Global warming may reduce carbon sink capacity of nothern ecosystems

Washington, Jan 3 (UNI) Warmer autumn temperatures is decreasing the duration of the net carbon uptake period (CUP), according to an international study investigating the carbon sink capacity of northern terrestrial ecosystems.

Net carbon uptake of northern ecosystems is decreasing in response to autumnal warming according to findings recently published in the journal Nature.

The carbon balance of terrestrial ecosystems is particularly sensitive to climatic changes in autumn and spring. Over the past two decades autumn temperatures in northern latitudes have risen by about 1.1 degrees Celsius with spring temperatures up by 0.8 degrees Celsius.

Many northern terrestrial ecosystems currently lose carbon dioxide (CO2) in response to autumn warming, offsetting 90 per cent of the increased carbon dioxide uptake during spring.

Using computer modeling to integrate forest canopy measurements and remote satellite data, researchers have found that while warm spring temperatures accelerate growth more than soil decomposition and enhance carbon uptake, autumn warming greatly increases soil decomposition and significantly reduces carbon uptake.

''If warming in autumn occurs at a faster rate than in spring, the ability of northern ecosystems to sequester carbon will diminish in the future,'' said Shilong Piao the lead author of the study from France.

''The potentially rapid decline in the future ability of northern terrestrial ecosystems to remove atmospheric carbon dioxide would make stabilisation of atmospheric CO2 concentrations much harder than currently predicted,'' added Philippe Ciais, a member of the research team and scientist from the Global Carbon Project.

UNI XC PD BD2023