Nitrous oxide, a study shows a 40% increase in emissions over the last 40 years

Tian H., (…), Regnier P. et al.

Earth System Science Data: link

Carbon Brief: link

A study coordinated by the Global Carbon Project in which the BGEOSYS group (Pierre Regnier, Department of Geosciences, Environment and Society) participated, reveals that nitrous oxide (N2O) emissions have increased by 40% during the period 1980-2020, strongly accelerating climate change.

Emissions of N2O to the atmosphere – a greenhouse gas with a much greater warming power than CO2 and CH4 – increased relentlessly between 1980 and 2020, reaching more than 10 million tonnes today, mainly due to agricultural practices. 

A study carried out under the auspices of the Global Carbon Project and published in the journal “Earth System Science Data” highlights that 74% of anthropogenic emissions are linked to agricultural production (2010-2020), reaching values never observed before. This excess nitrogen contributes to soil, water and air pollution. In the atmosphere, it contributes to the destruction of the ozone layer and exacerbates climate change.

Pierre Regnier, Full Professor in the Department of Geosciences, Environment & Society, Biogeochemistry and Earth System Modelling, is this academic year “Hess Distinguished Visiting Professor” at Princeton University (NJ, USA).

Invited by the “Department of Geoscience and High Meadows Environmental Institute”, he will work closely with Professor Laure Respandy and her research group in physical and biogeochemical oceanography. The aim of the stay is to build on a nascent collaboration focused on a better understanding of the role of the ocean in the global carbon cycle.

The collaboration between our institution and Princeton University will mobilize methods combining “data science” and “Earth system modelling”. These methods will better resolve the spatial and temporal variability of CO2 exchanges at the air-sea interface, elucidate the physical and biogeochemical processes that regulate these exchanges, and reconstruct the long-term evolution of the carbon cycle from the pre-industrial period to the end of the 21st century.

 

Prof. Sandra Arndt is one of four international scientists who join the new Norwegian Excellence Centre for ice, Cryosphere, Carbon and Climate (iC3)  in Adjunct Professor positions (20%) at UiT (The Arctic University of Norway).

iC3 produces ground-breaking insights into how the links between ice sheets, carbon cycles and ocean ecosystems are impacting life on earth.

The geologic history of seawater oxygen isotopes from marine iron oxides

Galili N., Shemesh A., Yam R., Brailovsky I., Sela-Adler M., Schuster E.M., Collom C., Bekker A., Planavsky N., Macdonald F.A., Préat A., Rudmin M., Trela W., Sturesson U., Heikoop J.M., Aurell M., Ramajo J. and Halevy I.

https://science.sciencemag.org/content/365/6452/469

Abstract

The oxygen isotope composition (δ¹⁸O) of marine sedimentary rocks has increased by 10 to 15 per mil since Archean time. Interpretation of this trend is hindered by the dual control of temperature and fluid δ¹⁸O on the rocks’ isotopic composition. A new δ¹⁸O record in marine iron oxides covering the past ~2000 million years shows a similar secular rise. Iron oxide precipitation experiments reveal a weakly temperature-dependent iron oxide–water oxygen isotope fractionation, suggesting that increasing seawater δ¹⁸O over time was the primary cause of the long-term rise in δ¹⁸O values of marine precipitates. The ¹⁸O enrichment may have been driven by an increase in terrestrial sediment cover, a change in the proportion of high- and low-temperature crustal alteration, or a combination of these and other factors.