Greenhouse gases unbalanced
How human intervention changes wetlands
(Press-News.org) 25.03.2015: Natural wetlands usually emit methane and sequester carbon dioxide. Anthropogenic interventions, in particular the conversion of wetlands for agriculture, result in a significant increase in CO2 emissions, which overcompensate potential decreases in methane emission. A large international research team now calculated that the conversion of arctic and boreal wetlands into agricultural land would result in an additional cumulative radiative forcing of about 0,1 MilliJoule (mJ) per square meter for the next 100 years. The conversion of temperate wetlands into agricultural land would even result in a cumulative radiative forcing of 0,15 mJ per square meter. Converting forested wetlands into managed forests also contributes to increased warming, albeit much less than the conversion of non-forested wetlands.
Wetlands are unique ecosystems, which - under natural conditions - are the single largest natural source of the greenhouse gas methane (CH4) but at the same time an important sink for the greenhouse gas carbon dioxide (CO2). The climate footprint of these ecosystems depends on the balance of these two important greenhouse gases. Despite methane being 28 times more potent as a greenhouse gas than carbon dioxide (in a 100 year time span), the conversion of natural wetlands into agricultural or forested ecosystems and its associated decrease in methane emissions still leads to an overall warming effect. „The human impact on wetlands, such as drainage, results in a shift of the climate footprint of that wetland" says Torsten Sachs at the GFZ German Research Centre for Geosciences, co-author of the study. „The overall balance of these two differently active greenhouse gases and thus the climate footprint of a wetland over different time spans depend on the relative sign and magnitude of these ecosystem-atmosphere fluxes."
The global impact is still rather uncertain due to large temporal and spatial variability and a lack of data on the complex interactions between environmental drivers such as temperatures of land, water, and sediment, water levels, vegetation, nutrient availability, among others, and the additional anthropogenic impacts such as land use change.
To calculate the net ecosystem carbon balance of wetland ecosystems, the more than 40 member research team synthesized data from almost 30 differently affected arctic, boreal, and temperate study sites across the globe. Simultaneous measurements of the ecosystem-atmosphere CO2 and CH4 fluxes in continental North America, Greenland, Europe, and Russia were used for analyses and modeling. For sites with a full annual dataset of CO2 and CH4 fluxes, natural and converted sites were paired in all possible combinations within similar ecosystem types. „To determine the climate impact of the conversion, we used the difference of the net ecosystem carbon balance between the site pairs as series of consecutive annual mass pulses and integrated their effect on tropospheric greenhouse gas concentrations" explains GFZ researcher Sachs. The different radiative efficiencies and atmospheric residence times of the greenhouse gases were accounted for when the radiative forcing was calculated for the period from 2000 - 2100.
Ana Maria Roxana Petrescu et. al.: "Uncertain climate footprint of wetlands under human pressure" Proceedings of the National Academy of Science, PNAS Early Edition, 24.03. 2015, http://www.pnas.org/cgi/doi/10.1073/pnas.1416267112
A photo in a printable resolution may be found here:
Caption: Automatic flux measurement chambers and an eddy covariance system to determine turbulent exchange fluxes of heat, water vapor, CO2, and CH4 between a re-wetted peatland and the atmosphere at Zarnekow, NE Germany (photo: Daniela Franz, GFZ)
ELSE PRESS RELEASES FROM THIS DATE:
AURORA, Colo. (March 25, 2015) - Coordinating patient care between hospital clinicians and primary-care physicians is a significant challenge due to poor communication and gaps in information-sharing strategies, according to a study led by physicians at the School of Medicine of the University of Colorado Anschutz Medical Campus.
The inability to share timely information can increase the risk of missed test results and hospital readmissions, according to the study's corresponding author, Christine D. Jones, MD, assistant professor of medicine and director of the Hospital ...
PROVIDENCE, R.I. [Brown University] -- By looking at the molecular aftermath of concussion in an unusual way, a team of researchers at Brown University and the Lifespan health system has developed a candidate panel of blood biomarkers that can accurately signal mild traumatic brain injury within hours using standard, widely available lab arrays. The results appear in a new study in the Journal of Neurotrauma.
Many researchers have reported recent progress in identifying possible blood biomarkers for concussion -- an advance sought because diagnosis is currently limited ...
Singapore, 18 March 2015- A multi-disciplinary team of doctors and scientists from Singapore has characterised the genetic changes associated with the spread of colorectal cancer to the liver. This finding is significant in helping to develop personalised diagnostic tests for patients with colorectal cancer based on the genetic changes present in each individual's colon tumour. The research team comprises representatives from National Cancer Centre Singapore (NCCS), Singapore General Hospital (SGH), Duke-NUS Graduate Medical School (Duke-NUS), A*STAR's Genome Institute ...
Across a number of faiths and cultures, people tend to date and marry others who share their religious beliefs. Now, new psychology research from New Zealand's University of Otago suggests this phenomenon--known as 'religious homogamy'--is partially a result of inferences about religious people's personalities.
The researchers measured how religious and non-religious individuals perceive the 'openness'--a primary dimension of personality associated with intellectual curiosity--of potential religious and non-religious mates. They found that non-religious participants in ...
This news release is available in French. Alberta Pregnancy Outcomes and Nutrition (APrON) is a birth cohort involving over two thousand women and their infants from Calgary and Edmonton that was funded by Alberta Innovates Health Solutions and includes researchers at the University of Alberta and the University of Calgary. The main objective of APrON is to understand the relationship between maternal nutrient status during pregnancy and maternal mental health and child health and development. As part of the project, the APrON team studied the first 600 women in the ...
Lifestyle-related cardiometabolic risk factors cluster already in children in the same way as in adults, according to research from the University of Eastern Finland. A cardiometabolic risk score was used to evaluate cardiometabolic risk in different age groups. The results show that risk factor levels even lower than those generally accepted as risk factor thresholds for type 2 diabetes and atherosclerotic vascular disease are harmful when several risk factors cluster.
In addition, a common mutation on the PNPLA3 gene associated with fatty liver in adults was found to ...
CRISPR-Cas9 is a powerful new tool for editing the genome. For researchers around the world, the CRISPR-Cas9 technique is an exciting innovation because it is faster and cheaper than previous methods. Now, using a molecular trick, Dr. Van Trung Chu and Professor Klaus Rajewsky of the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch and Dr. Ralf Kühn, MDC and Berlin Institute of Health (BIH), have found a solution to considerably increase the efficiency of precise genetic modifications by up to eightfold (Nature Biotechnology: doi:10.1038/nbt.3198)**.
Noisy and cramped conditions in trains, planes and airports are discouraging many commuters and business people from working while travelling, new research shows.
Sociologist Dr Donald Hislop and psychologist Dr Carolyn Axtell found that the most popular place to work was in vehicles in the car park of a motorway service station.
In a paper in the journal Work, Employment and Society, Dr Hislop, of Loughborough University, and Dr Axtell, of the University of Sheffield, say "significant variations" in noise and lack of space "inhibited people's ability to work" on ...
A new study in the Journal of Clinical Sleep Medicine revealed that 44 percent of adults with sickle cell disease who report trouble sleeping actually have a clinical diagnosis of sleep disordered breathing, including sleep apnea, which lowers their oxygen levels at night.
"Previous research identified pain and sleep disturbance as two common symptoms of adult sickle cell disorder," said Sunil Sharma, M.D., Associate Professor of Pulmonary and Critical Care Medicine, Sidney Kimmel Medical College at Thomas Jefferson University and first author on the study. "We wanted ...
The UN Intergovernmental Panel on Climate Change (IPCC) periodically releases Assessment Reports in order to inform policymakers and the public about the latest scientific evidence on climate change. The publication of each report is a key event in the debate about climate change, but their reception and coverage in the media has varied widely.
A study, published today in the journal Nature Climate Change, has for the first time analysed how Twitter, TV and newspapers reported the IPCC's climate evidence. Understanding how media coverage varies is important because people's ...
LAST 30 PRESS RELEASES:
[Press-News.org] Greenhouse gases unbalanced
How human intervention changes wetlands