Navigation Links
Tropical ecosystems regulate variations in Earth's carbon dioxide levels

Rising temperatures, influenced by natural events such as El Nio, have a corresponding increase in the release of carbon dioxide from tropical forest ecosystems, according to a new study out today.

The study, published in the journal Proceedings of the National Academy of Sciences, found that a temperature anomaly of just 1C (in near surface air temperatures in the tropics) leads to a 3.5-Petagram (billion tonnes of carbon) anomaly in the annual CO2 growth rate, on average. This is the equivalent of 1/3 of the annual global emissions from the combustion of fossil fuels and deforestation together.

Importantly, the NASA Earth Exchange (NEX) study results provide scientists with a new diagnostic tool to understand the global carbon cycle as it undergoes major changes due to the influences of human activities.

NASA study co-author, CSIRO's Dr Pep Canadell, said that the study's 50-year analysis centred on temperature and rainfall patterns during El Nio years, when temperatures increase in tropical regions and rainfall decreases. An accompanying analysis assessed the effects of volcanic eruptions, which lead to decreased temperatures due to volcanic aerosols in the atmosphere.

"Our study indicates that carbon exchanges in tropical ecosystems are extremely sensitive to temperature, and they respond with the release of emissions when warmer temperatures occur".

"Many processes involved in this response are the same as what is known as the carbon-climate feedback, which it is thought will lead to an acceleration of carbon emissions from vegetation and soils and into the atmosphere under future climate change.

"The observed temperature changes are more important than changes in rainfall in influencing concentration of atmospheric CO2".

"Warming is the one thing that we know with most certainty will occur under climate change in the tropics, but there are still large uncertainties about the future precipitation in tropical regions," says Dr Canadell, who is also Executive Director of the Canberra-based Global Carbon Project.

"What we have is a strong and robust coupling between seasonal variations in atmospheric CO2 growth and tropical temperatures over the past 50 years and this provides us with a key diagnostic tool to assist in our understanding of the global carbon cycle," he said.

The team, led by Dr Weile Wang, analysed widely available data on atmospheric carbon dioxide concentration and global air temperature between 1959 and 2011.

"What we learned is that in spite of droughts, floods, volcano eruptions, El Nio and other events, the Earth system has been remarkably consistent in regulating the inter-annual variations in atmospheric carbon dioxide levels," said Dr Weile Wang, lead author of the paper.

What they found was, unlike in other parts of the planet, year-to-year changes in temperature over the tropics act in concert on both photosynthesis (absorption of carbon dioxide) and respiration (release of carbon dioxide), the two important mechanisms that naturally regulate year-to-year changes in atmospheric carbon dioxide concentrations.

"For example, a rise in temperature over the tropical regions results in a decline in photosynthesis as well as an increase in carbon losses through respiration, amplifying the temperature effect on carbon cycling" says Rama Nemani, Principal scientist for the NEX project.


Contact: Craig Macaulay
CSIRO Australia

Related biology news :

1. Palms reveal the significance of climate change for tropical biodiversity
2. The absence of elephants and rhinoceroses reduces biodiversity in tropical forests
3. Native plant restoration not enough to maintain tropical dry forests in Hawaii
4. Rodent robbers good for tropical trees
5. Have thieving rodents saved tropical trees?
6. Thieving rodents: Did they save tropical trees?
7. Tropical plankton invade Arctic waters
8. Tropical arks reach tipping point
9. Prestigious Royal Society of Tropical Medicine and Hygiene journals join Oxford University Press
10. Testosterone regulates solo song of tropical birds
11. Researchers investigate impacts of climate change on rare tropical plants
Post Your Comments:
(Date:6/15/2016)... York , June 15, 2016 ... new market report titled "Gesture Recognition Market by Application ... Forecast, 2016 - 2024". According to the report, the  ... 11.60 billion in 2015 and is estimated to ... USD 48.56 billion by 2024.  Increasing ...
(Date:6/7/2016)... , June 7, 2016  Syngrafii Inc. and ... business relationship that includes integrating Syngrafii,s patented LongPen™ ... project. This collaboration will result in greater convenience ... credit union, while maintaining existing document workflow and ... ...
(Date:6/2/2016)... June 2, 2016   The Weather Company , an ... Ads, an industry-first capability in which consumers will be able ... to ask questions via voice or text and receive relevant ... Marketers have long sought an advertising solution ... can be personal, relevant and valuable; and can scale across ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... ... June 27, 2016 , ... Rolf K. Hoffmann, former senior ... the University of North Carolina Kenan-Flagler Business School effective June 27. ... Kenan-Flagler, with a focus on the school’s international efforts, leading classes and participating ...
(Date:6/24/2016)... DIEGO , June 24, 2016 ... more sensitively detects cancers susceptible to PARP inhibitors ... circulating tumor cells (CTCs). The new test has ... HRD-targeted therapeutics in multiple cancer types. ... targeting DNA damage response pathways, including PARP, ATM, ...
(Date:6/23/2016)... WI (PRWEB) , ... June 23, 2016 , ... ... supplements, is pleased to announce the launch of their brand, UP4™ Probiotics, into ... for over 35 years, is proud to add Target to its list of ...
(Date:6/23/2016)... , June 23, 2016 Houston Methodist ... the Cy-Fair Sports Association to serve as their ... agreement, Houston Methodist Willowbrook will provide sponsorship support, ... connectivity with association coaches, volunteers, athletes and families. ... the Cy-Fair Sports Association and to bring Houston ...
Breaking Biology Technology: