Guest essay by Eric Worrall
Researchers have claimed that the laughing gas released when swamps are drained is no laughing matter.
Draining peatlands gives global rise to greenhouse laughing-gas emissions
UNIVERSITY OF BIRMINGHAM
PUBLIC RELEASE: 28-MAR-2018
Drained fertile peatlands around the globe are hotspots for the atmospheric emission of laughing-gas – a powerful greenhouse gas called nitrous oxide, which is partly responsible for global warming and destruction of the ozone layer, a new study shows.
Research into natural peatlands such as fens, swamps and bogs, as well as drained peatlands, found that either draining wet soils or irrigating well drained soils boosts the emission of nitrous oxide significantly.
Prof Ülo Mander, Senior Lecturer in Biogeochemistry, at the University of Tartu, who conceived this research with a global network of 36 scientists said: “Nitrous oxide is no laughing matter – it is a significant contributor to global climate change and depletion of the ozone layer, which protects our planet from cosmic radiation.
“Organic soils, such as fens, swamps, bogs and drained peatlands, make up more than one-tenth of the world’s soil nitrogen pool and are a significant global source of laughing gas. They are significant sources of nitrous oxide when drained for cultivation.”
The abstract of the study;
Nitrogen-rich organic soils under warm well-drained conditions are global nitrous oxide emission hotspots
Nitrous oxide (N2O) is a powerful greenhouse gas and the main driver of stratospheric ozone depletion. Since soils are the largest source of N2O, predicting soil response to changes in climate or land use is central to understanding and managing N2O. Here we find that N2O flux can be predicted by models incorporating soil nitrate concentration (NO3−), water content and temperature using a global field survey of N2O emissions and potential driving factors across a wide range of organic soils. N2O emissions increase with NO3− and follow a bell-shaped distribution with water content. Combining the two functions explains 72% of N2O emission from all organic soils. Above 5 mg NO3−-N kg−1, either draining wet soils or irrigating well-drained soils increases N2O emission by orders of magnitude. As soil temperature together with NO3− explains 69% of N2O emission, tropical wetlands should be a priority for N2O management.
Back in 2010 Marc Morano of Climate Depot predicted that the Laughing Gas crisis would be marketed as a potential replacement for the faltering CO2 scare.