Nitrous oxide, a greenhouse gas, is on the rise

November 18, 2019

CAMBRIDGE, MD (November 18, 2019)--Most of us know nitrous oxide as "laughing gas," used for its anaesthetic effects. But nitrous oxide (N2O) is actually the third most important long-lived greenhouse gas, after carbon dioxide (CO2) and methane. Nitrous oxide is also one of the main stratospheric ozone depleting substances-- and we are releasing more of it into the atmosphere than previously thought, according to a new study published this week in Nature Climate Change.

"We see that the N2O emissions have increased considerably during the past two decades, but especially from 2009 onwards," said lead scientist Rona L. Thompson from NILU-Norwegian Institute for Air Research. "Our estimates show that the emission of N2O has increased faster over the last decade than estimated by the Intergovernmental Panel on Climate Change (IPCC) emission factor approach."

Increasing use of nitrogen fertilizers is leading to higher N2O levels in the atmosphere

In the study, Thompson and scientists including Eric Davidson of the University of the Maryland Center for Environmental Science found that nitrous oxide in the atmosphere has risen steadily since the mid-20th century. This rise is strongly linked to an increase in nitrogen substrates released to the environment. Since the mid-20th century, the production of nitrogen fertilizers, widespread cultivation of nitrogen-fixing crops (such as clover, soybeans, alfalfa, lupins, and peanuts), and the combustion of fossil and biofuels has increased enormously the availability of nitrogen substrates in the environment.

"The increased nitrogen availability has made it possible to produce a lot more food," Thompson said. "The downside is of course the environmental problems associated with it, such as rising N2O levels in the atmosphere."

Rate of increase has been underestimated

The study authors found that N2O emissions increased globally to approximately 10% of the global total between 2000-2005 and 2010-2015. This is about twice the amount reported to the United Nations Framework Convention on Climate Change based on the amount of nitrogen fertilizer and manure used and the default emission factor specified by the IPCC. The researchers argue that this discrepancy is due to an increase in the emission factor (that is, the amount of N2O emitted relative to the amount of N-fertilizer used) associated with a growing nitrogen surplus. This suggests that the IPCC method, which assumes a constant emission factor, may underestimate emissions when the rate of nitrogen input and the nitrogen surplus are high.

From scientific methods to practical measures

"This new publication demonstrates both how we can solve a problem of growing greenhouse gas emissions and how current efforts are falling short in some regions of the world," said co-author Eric Davidson of the University of Maryland Center for Environmental Science. "These emissions come primarily from using fertilizers to grow food and increasing livestock herds, but we've learned how to produce more food with less nitrous oxide emission."

"In Europe and North America, we have succeeded in decreasing growth in nitrous oxide emissions, an important contributor to climate change and stratospheric ozone depletion," he added. "Unfortunately, the same can't be said for Asia and South America, where fertilizer use, intensification of livestock production, and the resulting nitrous oxide emissions are growing rapidly.

"The good news is that this problem can be solved, but the less good news is that it will take a global effort, and we are far from there yet," he said.
-end-
"Acceleration of global N2O emissions seen from two decades of atmospheric inversion" was published in Nature Climate Change.

UNIVERSITY OF MARYLAND CENTER FOR ENVIRONMENTAL SCIENCE

A globally eminent research and graduate institution focused on advancing scientific knowledge of the environment, the University of Maryland Center for Environmental Science provides sound advice to help state and national leaders manage the environment and prepares future scientists to meet the global challenges of the 21st century. http://www.umces.edu

University of Maryland Center for Environmental Science

Related Climate Change Articles from Brightsurf:

Are climate scientists being too cautious when linking extreme weather to climate change?
Climate science has focused on avoiding false alarms when linking extreme events to climate change.

Mysterious climate change
New research findings underline the crucial role that sea ice throughout the Southern Ocean played for atmospheric CO2 in times of rapid climate change in the past.

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.

Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.

Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.

Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.

A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.

Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).

Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.

Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.

Read More: Climate Change News and Climate Change Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.