Nitrate Fertilizers Are Cooling the Planet – Is It Worth It?

Essay by Eric Worrall

“… Therefore, the current findings are no reason to ignore harmful effects, let alone consider nitrogen addition as a measure to combat global warming. …”

JULY 24, 2024

Researchers find that the net impact of man-made nitrogen reduces global warming

by Eberhard Fritz, Max Planck Society

Nitrogen fertilizers and nitrous oxide from fossil fuels are known to be harmful to the environment: they pollute air and drinking water, lead to overfertilization of land and water ecosystems, reduce biodiversity and destroy the ozone layer.

However, in terms of climate, they have a network of Cooling effect. This is the conclusion reached by an international team led by scientists from the Max Planck Institute for Biogeochemistry in Jena in a comprehensive analysis. In it, the scientists assessed the different climate impacts of nitrogen compounds from agricultural and non-agricultural sources.

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Without man-made nitrogen, the climate would warm much more.

An international research team led by Sönke Zaehle and Cheng Gong from the Max Planck Institute for Biogeochemistry has now summarized the different warming and cooling effects in a study published in the journal Nature. published in magazine Nature. They found that reactive nitrogen, entering the Earth system through human activities, cools the climate by -0.34 watts per square meter—in climate research, this is known as net negative radiative forcing.

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“This may seem like good news, but you have to remember that nitrogen emissions have many harmful effects, such as on health, biodiversity and the ozone layer,” Zaehle said. “So the current findings are no reason to ignore the harmful effects, let alone consider additional nitrogen inputs as a means to combat global warming.”

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Read more: https://phys.org/news/2024-07-net-effect-nitrogen-attenuate-global.html

Summary of the study;

Open Access

Publication date: July 24, 2024

Net global climate impact of anthropogenic reactive nitrogen

Success, Han Cam Thien, Hong Lieu, Naiqing Pan, Shufen Pan, Akihiko Ito, Atul K. Jain, Sian Kou-Giesbrecht, Luckily Joos, Thanh Ton, Hao Thi, Nicolas Vuichard, Thanh Chau, Changhui Peng, Federico Maggi, Fiona HM Road & Sonke Zaehle

Nature (2024)Quote this article

abstract

Human activities have significantly increased the amount of reactive nitrogen (Nr) in the Earth system since pre-industrial times.^first,2contributing to widespread eutrophication and air pollution^3,4,5,6. Increased Nr may also affect global climate through various effects on atmospheric and land processes, but the cumulative net climate impact remains unclear. Here we show that anthropogenic Nr causes a net negative direct radiative forcing of −0.34[−0.20, −0.50]W m⁻² in 2019 relative to 1850. This net cooling effect is the result of increased aerosol loading, reduced methane lifetime, and increased terrestrial carbon sequestration associated with anthropogenic increases in Nr, which are not offset by the warming effects of enhanced atmospheric nitrous oxide and ozone. Future projections using three representative scenarios suggest that this cooling effect is likely to be weakened primarily by reduced aerosol loading and increased methane lifetime, while Nr in particular₂O-induced warming is likely to continue to increase under all scenarios. Our results indicate that future reductions in anthropogenic Nr to achieve climate protection goals need to be accompanied by enhanced efforts to reduce anthropogenic greenhouse gas emissions to achieve climate change mitigation goals under the Paris Agreement.

Read more: https://www.nature.com/articles/s41586-024-07714-4

This news follows the recent good and bad news that CO2 is greening the deserts;