Study: Human Activity & Nitrogen Makes the Earth Greener

Simian Practicalist
8 minutes ago
2 min read

A study by J. Trepel et al titled “Global analysis suggests nitrogen deposition as an underestimated driver of vegetation greening” published on 20 July 2026 finds that our breathing and passing gas make trees grow.

The paper is 12 pages with the main text about 8 pages. The remaining are references.

The study attempts to model the effects of nitrogen (N) deposition on greening at a global scale from 2001 to 2024. It is not merely nitrogen in the atmosphere, nitrogen from human activity is also a factor.

Emissions were mainly estimated from seven key categories of human activities: power generation, industry, residential use, agriculture, ground transport, aviation and shipping.

In short, the study observed a “positive relationship between nitrogen deposition and EVI [enhanced vegetation index] increases”.

Globally, we found a significant overall greening trend (EVI; intercept estimate: 5.43 [95% confidence interval (CI): 5.21, 5.65]) and stronger increases in EVI in areas with high nitrogen deposition (coefficient estimate [ß] = 1.82 [1.68, 1.96]; Fig. 1).

Not surprisingly, areas subject to human land modification and frequent fires have a slower increase in EVI.

Interestingly, when comparing protected areas (PAs) to unprotected areas, they did not observe “strong differences between global change drivers” or “the relationship of N deposition and other global change drivers with vegetation greenness trend drivers”.

Also noteworthy is that the EVI increase was “slightly slower in strict PAs compared to unprotected controls”.

Amongst other things, the authors also mention that “[g]lobal vegetation models currently attribute most of the observed greening to warming and CO₂ fertilisation”. However, it is known that greening is limited by nutrients, including nitrogen, which is supported by this study.

So, if we want to keep hugging trees, they seem to do just fine with nitrogen from human activity so keep breathing, passing gas, breeding cows for steaks and burning fossil fuels.