THREAD: N₂O
We have a new paper in @nature on nitrous oxide (N₂O), five years in the making!
Like many GHGs, N₂O concentrations have been stable for thousands of years, but that balance between sources & sinks has been dramatically changed by humans.
rdcu.be/b8cgZ
We have a new paper in @nature on nitrous oxide (N₂O), five years in the making!
Like many GHGs, N₂O concentrations have been stable for thousands of years, but that balance between sources & sinks has been dramatically changed by humans.
rdcu.be/b8cgZ
2. N₂O is a potent GHG, 300 times worse than CO₂ over 100 years (GWP). It destroys the ozone layer & contributes to water pollution.
N₂O is ~7% of current radiative forcing, but because of its long lifetime & difficulty to mitigate, this will increase even in 1.5°C scenarios.
N₂O is ~7% of current radiative forcing, but because of its long lifetime & difficulty to mitigate, this will increase even in 1.5°C scenarios.
3. N₂O comes almost equally from natural (60%) & anthropogenic sources (40%).
Natural sources are dominated by microbial processes that break down nitrogen-containing compounds in the soil & oceans. These sources have previously balanced with the atmospheric chemical sinks.
Natural sources are dominated by microbial processes that break down nitrogen-containing compounds in the soil & oceans. These sources have previously balanced with the atmospheric chemical sinks.
4. Anthropogenic sources:
* Agriculture: Fertilisers & manure (50%, ↑1.4%/yr)
* Other: Fossil fuels, industry, wastewater, biomass burning (25%, ↑0.9%/yr)
* Indirect: Transport to ecosystems by land, water, & air (15%, ↑1%/yr)
* Feedbacks: 10%, increasing but high variability
* Agriculture: Fertilisers & manure (50%, ↑1.4%/yr)
* Other: Fossil fuels, industry, wastewater, biomass burning (25%, ↑0.9%/yr)
* Indirect: Transport to ecosystems by land, water, & air (15%, ↑1%/yr)
* Feedbacks: 10%, increasing but high variability
5. Anthopogenic emissions by region:
* East Asia: 20%, ↑1.3%/yr
* North America: 15%, ↑1.0%/yr
* Africa: 15%, ↑0.5%/yr
* South Asia: 11%, ↑2%/yr
* Europe: 11%, ↓0.2%/yr
* South America: 10%, ↑3.3%/yr
* SE Asia: 6%, ↑2.8%/yr
* Russia: 4%, ↑1.4%/yr
* Mid East: 4%, ↑2.3%/yr
* East Asia: 20%, ↑1.3%/yr
* North America: 15%, ↑1.0%/yr
* Africa: 15%, ↑0.5%/yr
* South Asia: 11%, ↑2%/yr
* Europe: 11%, ↓0.2%/yr
* South America: 10%, ↑3.3%/yr
* SE Asia: 6%, ↑2.8%/yr
* Russia: 4%, ↑1.4%/yr
* Mid East: 4%, ↑2.3%/yr
6. Anthropogenic emissions per person vary a factor of five between regions.
Generally, rich countries have higher per capita emissions, but this would be even higher if emissions from the production of imported food was included (not considered in our analysis).
Generally, rich countries have higher per capita emissions, but this would be even higher if emissions from the production of imported food was included (not considered in our analysis).
7. Some good news...
Europe has been able to reduce emissions:
* Measures in industry have led to a solid reduction in emissions
* Agriculture has flattened emissions, despite increasing agriculture output.
Mitigating N₂O emissions is hard, but there are low hanging fruits!
Europe has been able to reduce emissions:
* Measures in industry have led to a solid reduction in emissions
* Agriculture has flattened emissions, despite increasing agriculture output.
Mitigating N₂O emissions is hard, but there are low hanging fruits!
8. Global emission are heading in the wrong direction, & are likely much higher than estimates used in scenario analysis.
Even deep mitigation (1.5°C, 2°C) only has modest reductions in N₂O, but the more effort on N₂O leads to lower overall temperatures (or less work on CO₂).
Even deep mitigation (1.5°C, 2°C) only has modest reductions in N₂O, but the more effort on N₂O leads to lower overall temperatures (or less work on CO₂).
9. Though, because of the long lifetime of N₂O, atmospheric concentrations will continue to grow throughout the century even if mitigation happens.
This makes N₂O increasingly important, particularly in a world that needs more food, fibre, & energy!
This makes N₂O increasingly important, particularly in a world that needs more food, fibre, & energy!
10. A big effort from @gcarbonproject & @INI_Global, with over 50 scientists involved.
Great resources available: globalcarbonproject.org/nitrousoxidebu…
Read the article: nature.com/articles/s4158…, also free rdcu.be/b8cgZ
This thread is based on a blog post: cicero.oslo.no/en/posts/news/…
Great resources available: globalcarbonproject.org/nitrousoxidebu…
Read the article: nature.com/articles/s4158…, also free rdcu.be/b8cgZ
This thread is based on a blog post: cicero.oslo.no/en/posts/news/…
Extra: A rather embarrassing mistake in the first tweet. I showed a figure of CO₂ concentration and not N₂O concentration.
Thanks for spotting @climpeter...
Here is the correct version csiro.au/en/Research/Oa…
Thanks for spotting @climpeter...
Here is the correct version csiro.au/en/Research/Oa…
Extra: A rather embarrassing mistake in the first tweet. I showed a figure of CO₂ concentration and not N₂O concentration.
Thanks for spotting @climpeter...
Here is the correct version csiro.au/en/Research/Oa…
Thanks for spotting @climpeter...
Here is the correct version csiro.au/en/Research/Oa…
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