That balance changes when peatlands are drained for farming. Lowering the water table allows oxygen to enter the soil, speeding up microbial activity. As microbes break down the previously preserved plant matter, carbon that has been stored for centuries is released into the atmosphere as carbon dioxide (CO₂).

Northern Peatlands Remain Understudied

Large areas of peatland across Europe and the Nordic region have been drained since the 1600s. Scientists have closely examined how drainage and shifting water levels affect greenhouse gas emissions in many of these regions.

Far less is known about the northernmost peatlands used for agriculture. These areas experience cold temperatures, short growing seasons, and extended daylight during summer months.

“From studies in warmer regions, we know that raising the groundwater level in drained and cultivated peatland often reduces CO₂ emissions, because the peat decomposes more slowly,” explains NIBIO researcher Junbin Zhao.

“At the same time, wetter and low-oxygen conditions can increase methane, since the microbes that produce methane thrive when there is almost no oxygen in the soil.”

Nitrous oxide can also increase under certain moisture conditions. When soil is damp but not completely waterlogged, nitrogen breakdown may stop midway, producing nitrous oxide instead of harmless nitrogen gas.

“Because each greenhouse gas reacts differently to changes in water level, one gas can go down while another goes up. That’s why it’s important to look at the overall gas balance,” says Zhao.

“We need to measure CO₂, methane, and nitrous oxide at the same time and throughout the whole season to understand the real net effect in the northernmost agricultural areas.”

Two Year Arctic Field Study in Northern Norway

To answer these questions, Zhao and his colleagues carried out a two year field study in 2022 and 2023 at NIBIO’s Svanhovd research station in the Pasvik Valley of Northern Norway. Automated chambers tracked CO₂, methane, and nitrous oxide emissions multiple times per day throughout the growing season.

“The experiment included five plots that together reflected typical management conditions found in a drained agricultural field — with different groundwater levels, different amounts of fertiliser, and different numbers of harvests per season,” Zhao explains.

The team focused on three key questions:

• Can raising the groundwater level make a cultivated Arctic peatland close to climate-neutral?
• Does the water level affect soil CO₂ emissions more than it affects plant CO₂ uptake?
• How do fertilization and harvesting influence the total climate balance?

Higher Groundwater Levels Cut CO₂ Emissions

When the Pasvik peatland was heavily drained, it released large amounts of CO₂, comparable to cultivated peatlands farther south. But when researchers raised the groundwater to between 25 and 50 cm below the surface, emissions dropped sharply.

“At these higher water levels, methane and nitrous oxide emissions were also low, giving a much better overall gas balance. Under such conditions, the field even absorbed slightly more CO₂ than it released,” says Zhao.

This suggests that maintaining higher groundwater levels in Arctic farmland could serve as an effective climate strategy.

“Our findings are especially interesting because emissions were measured continuously around the clock. This meant we captured short spikes of unusually high emissions and natural daily fluctuations, details often missed when measurements are taken only occasionally.”

Why Cold Arctic Climates Amplify the Effect

Raising the water table makes the soil wetter and reduces oxygen around plant roots. Plants become somewhat less active and absorb less CO₂ under these conditions.

Even so, overall CO₂ emissions from the field decline.

“This is because wet conditions mean that the field needs less light before it starts to absorb more CO₂ than it releases. When this threshold is reached earlier in the day, you get more hours with net carbon uptake,” Zhao explains.

“Our calculations show that this effect is especially strong in the north, due to the long, light summer nights. These provide many extra hours where the system remains on the positive side, which can increase total CO₂ uptake significantly.”

Temperature turned out to be another crucial factor. Once soil temperatures climbed above about 12°C, microbial activity intensified.

“At higher temperatures, microorganisms break down organic material faster, and both CO₂ and methane emissions rise,” says Zhao.

“This means that the effect of high water levels is greatest in cool climates — and that future warming could reduce the benefit. In practice, this means water levels must be considered together with temperature and local conditions.”

Fertilization and Harvesting Shape the Carbon Balance

Farm management practices also played a role. Adding more fertilizer boosted grass growth.

“More fertilizer produced more biomass but did not lead to noticeable changes in CO₂ or methane emissions in our experiment,” says Zhao.

Harvesting had a clearer impact. When grass was cut and removed, the carbon stored in plant material left the system.

“If harvesting is very frequent, more carbon can be taken out than is built up again over time. The peat layer may gradually lose carbon even when water levels are kept high,” Zhao explains.

For that reason, Zhao emphasizes that water management, fertilizer use, and harvesting schedules must be evaluated together. Steps that lower emissions in the short term could reduce long term carbon storage, potentially weakening soil quality.

“One solution could be paludiculture, i.e. growing plant species that tolerate wet conditions so that biomass can be produced without keeping the soil dry.”

Local Differences Matter for Climate Accounting

The researchers also observed significant variation within the same field. Some areas absorbed CO₂, while nearby sections released substantial amounts.

“Such local variation can greatly influence national climate accounting and how measures are designed, because one standard emission factor may not reflect reality everywhere,” Zhao says.

“The results from our study show a clear need for more detailed measurements and more precise water-level management in practice, especially where soils and farming conditions vary significantly between locations.”

Isoxazoline drugs are a relatively new class of antiparasitic medications prescribed by veterinarians around the world to protect pets from fleas and ticks. Introduced in 2013, they quickly gained popularity because they were the first oral treatments capable of controlling both pests for a month or longer. After pets take these medications, the active compounds pass through their bodies and are excreted in feces.

Drug Residues Enter Soil and Ecosystems

The European Medicines Agency has previously warned that these substances could contaminate ecosystems, although detailed information about how much of the drugs enter the environment remains limited. The main concern centers on how veterinary parasite treatments might affect species that are not the intended targets.

Isoxazolines are designed to kill fleas and ticks, but when treated animals eliminate the drugs, other insects may also be exposed. Research suggests pets can introduce these chemicals into the environment through feces, urine, and even shed hair. Of particular concern are dung-feeding insects such as flies, dung beetles, and some butterflies. These species play a vital role in breaking down waste, recycling nutrients, improving soil quality, and helping control pests. If they consume feces containing the drug residues, they may be harmed.

Study Tracks Isoxazoline Residues in Pet Feces

To better understand the risk, researchers in France monitored 20 dogs and 20 cats owned by veterinary students. The animals received isoxazoline treatments over a three month period. Scientists collected fecal samples to measure how much of the active ingredients remained and to estimate how much exposure dung-feeding insects could face.

The analysis focused on how these medications are eliminated in pet waste. Even after the recommended treatment period had ended, researchers detected two of the four active ingredients commonly found in isoxazoline products in the animals’ feces.

Potential Impact on Dung Feeding Insects

An environmental risk assessment based on these findings suggests that dung-feeding insects could experience high levels of exposure to isoxazoline compounds as a result of routine pet treatments. The researchers warn that this exposure could disrupt important ecological processes and potentially lead to serious consequences for environmental lifecycles.

This is the first time researchers have mapped genetic risk for hemochromatosis, sometimes called the ‘Celtic curse’, across the UK and Ireland. The condition has long been known to affect Scottish and Irish populations at higher rates, but until now its geographic distribution had not been clearly charted.

Experts say the findings could help health officials focus genetic screening in the areas most affected, allowing people at risk to be identified earlier and treated before serious complications develop.

Iron Overload Can Damage Organs Over Decades

Hemochromatosis often develops slowly. Excess iron can accumulate in organs for years or even decades before symptoms appear. If left untreated, it can lead to liver damage, liver cancer, arthritis, and other serious health problems. Early diagnosis makes a major difference. Regular blood donation to lower iron levels is a simple and effective treatment that can prevent much of the harm.

The disease is caused by inherited changes in DNA known as genetic variants. In the UK and Ireland, the main risk factor is a variant called C282Y.

Researchers at the University of Edinburgh analyzed genetic information from more than 400,000 people who took part in the UK BioBank and Viking Genes studies. They examined how common the C282Y variant was in 29 regions across the British Isles and Ireland.

Where the C282Y Gene Variant Is Most Common

The highest rates were found among people with ancestry from north west Ireland, where about one in 54 people are estimated to carry the variant. The Outer Hebrides followed closely at one in 62, and Northern Ireland at one in 71.

Mainland Scotland also showed elevated risk, particularly in Glasgow and southwest Scotland. In those areas, about one in 117 people carry the variant, reinforcing the long standing ‘Celtic Curse’ nickname.

Because the combined genetic risk is so high in these regions, researchers say targeted screening there would likely identify the greatest number of people with the condition.

Diagnosis Patterns and Possible Under Detection

The team also reviewed NHS England records and found more than 70,000 diagnosed cases of hemochromatosis. White Irish individuals were nearly four times more likely to be diagnosed than white British individuals.

Among white British individuals, those living in Liverpool were 11 times more likely to have a diagnosis than people in Kent. Researchers suggest this may reflect historical Irish migration, as more than 20 percent of Liverpool’s population was Irish in the 1850s.

In general, diagnosis rates in England mirror the pattern of genetic risk. However, Birmingham, Cumbria, Northumberland and Durham reported fewer cases than expected based on their genetic profiles. These areas may have undetected cases and could benefit from expanded screening efforts.

Comparable NHS prevalence data were not available for Scotland, Wales and Northern Ireland, so those regions were not included in that portion of the analysis.

The study was funded by the charity Haemochromatosis-UK and conducted in partnership with RCSI University of Medicine and Health Sciences. It was published in Nature Communications.

Calls for Community Wide Genetic Screening

Professor Jim Flett Wilson, Chair of Human Genetics at the University of Edinburgh, said: “If untreated, the iron-overload disease hemochromatosis can lead to liver cancer, arthritis and other poor outcomes. We have shown that the risk in the Hebrides and Northern Ireland is much higher than previously thought, with about one in every 60 people at risk, about half of whom will develop the disease. Early detection prevents most of the adverse consequences and a simple treatment — giving blood — is available. The time has come to plan for community-wide genetic screening in these high-risk areas, to identify as many people as possible whose genes mean they are at high risk of this preventable illness.”

Jonathan Jelley MBE JP, CEO of Haemochromatosis UK, said: “Although there are other forms and genotypes that can lead to iron overload, available research indicates C282Y presents as the greatest risk. This hugely important work has the potential to lead to greater targeted awareness, increased diagnosis and better treatment pathways for thousands of people affected by genetic hemochromatosis.

“As a charity we have already begun work on targeting and prioritizing hotspot areas of the UK for support including with our National Helpline and clinician education. Using this study we will continue to campaign for better allocation of public resources to this preventable condition that is all too often overlooked.”

Torcuil Crichton, the Labour MP for Na h-Eileanan an Iar (the Western Isles), has hemochromatosis and backs the push for screening in the Western Isles.

Torcuil Crichton MP said: “This research writes the case for community-wide screening in the Western Isles, Northern Ireland, and other hemochromatosis hotspots. I have previously raised this with Ministers in the House of Commons and this new evidence ought to be enough to persuade the UK National Screening Committee to review its position and approve a pilot screening program. The Western Isles offers a contained and distinct population sample to start from.

“Early identification, which I was lucky to have, means a whole range of bad health outcomes can be avoided and I’ll be urging Ministers and the Screening Committee to reconsider their stance.”