How Air Pollution Damages Earth’s Natural Carbon-Removal Systems
The Big Idea
When we talk about climate change, we usually focus on carbon dioxide, methane, and rising temperatures. But another important part of the story is happening in the atmosphere: ozone pollution is damaging the vegetation that helps remove carbon dioxide from the air.
Ground-level ozone harms plants, reduces photosynthesis, and limits plant growth. These effects weaken an important natural process that helps regulate the Earth’s carbon balance.
New research also shows that ozone produced by wildfires can contribute to additional carbon losses in the Amazon rainforest, beyond the carbon released directly by burning vegetation.
Ozone is not just an air pollutant. It is a biological climate amplifier that can weaken Earth’s natural defenses against global warming.
1. Ozone Damages the Plants That Absorb Carbon
Plants absorb carbon dioxide through photosynthesis. Using sunlight, they convert carbon dioxide into the materials needed to grow.
But ground-level ozone interferes with this process.
Ozone enters leaves through tiny openings called stomata. It can cause chemical damage, reduce photosynthesis, affect water regulation, and limit plant growth.
A global meta-analysis combining 144 studies found that elevated ozone exposure was associated with average reductions of:
- 18.5% in photosynthesis.
- 10.1% in stomatal conductance, which helps regulate gas exchange and water loss.
- 18.7% in total plant biomass.
These are average responses in the studies analyzed, not universal percentages for every plant or ecosystem.
The important finding is clear: elevated ozone exposure can significantly impair the biological processes responsible for plant growth and carbon absorption.
2. Why Plant Damage Matters for Climate Change
Healthy vegetation removes carbon dioxide from the atmosphere and stores carbon in leaves, trunks, roots, and soils.
When ozone damages vegetation, affected plants may absorb less carbon dioxide and accumulate less biomass than they otherwise would.
That means less carbon is transferred from the atmosphere into living vegetation. The resulting effect on atmospheric CO₂ depends on the size and duration of the reduction and on what happens elsewhere in the carbon cycle.
This creates an important climate connection:
Ozone damages vegetation. Damaged vegetation absorbs less carbon. Weakened carbon uptake makes it harder for nature to slow the accumulation of atmospheric CO₂.
This mechanism is supported by plant research and global meta-analysis. Its full contribution to global warming requires additional carbon-cycle analysis.
3. Wildfires Create an Additional Ozone Problem
A 2026 study examined the effects of fire-derived ozone on Amazon forests under extreme drought.
The researchers estimated that carbon losses associated with fire-derived ozone were equivalent to approximately one-quarter of the direct carbon emissions from fires.
This reveals an important additional pathway of damage.
When vegetation burns, carbon is released directly into the atmosphere. But wildfire emissions can also contribute to ozone formation. That ozone can damage vegetation exposed to the pollution, including plants that were not directly burned.
The result is two connected effects:
- Wildfires release carbon through combustion.
- Fire-derived ozone damages vegetation and contributes to additional carbon losses.
The study quantified this relationship for its Amazon analysis. The same ratio should not be assumed for every wildfire or forest.
Nevertheless, the finding demonstrates why measuring the carbon released by flames alone does not capture the full range of wildfire-related carbon losses.
4. Drought, Fire, and Ozone Interact
The Amazon study also found that substantial ozone-related damage could occur during extreme drought.
Drought can cause plants to close their stomata to conserve water. This can reduce ozone uptake, but it does not eliminate the combined effects of water stress, wildfire, and atmospheric pollution.
Drought can weaken vegetation and contribute to conditions favorable to fire. Fires release carbon and ozone precursors. The resulting ozone can damage vegetation and interfere with carbon uptake.
These processes connect drought, wildfire, atmospheric chemistry, and the carbon cycle.
The effects are not identical everywhere. Weather, vegetation type, fire intensity, and atmospheric chemistry influence the outcome.
The central point is that climate-related stresses interact, and their combined consequences can extend beyond the direct effects of any single stressor.
5. The Ozone Feedback Framework
A climate feedback occurs when a change triggers additional changes that reinforce the original process.
The Ozone Feedback Framework connects the observed mechanisms into a larger sequence:
Ozone pollution
↓
Vegetation damage
↓
Reduced photosynthesis and plant growth
↓
Weaker carbon uptake
↓
Additional carbon remaining in the atmosphere relative to the healthier-vegetation scenario
Wildfire adds another pathway:
Wildfire releases carbon and ozone precursors.
↓
Ozone forms in the atmosphere.
↓
Vegetation exposed to ozone is damaged.
↓
Additional carbon losses can occur.
These connections explain how air pollution can contribute to climate change through biological processes, not just through its direct effects on atmospheric energy.
The complete global strength of this feedback has not yet been established by a single integrated analysis. But its component mechanisms are documented, and the Amazon research quantifies one important regional connection.
6. What the Evidence Establishes
Three conclusions emerge from the research.
First, ozone damages plants. Global research documents reductions in photosynthesis and biomass under elevated ozone exposure.
Second, ozone affects the carbon cycle. Reduced plant productivity impairs the transfer of carbon from the atmosphere into vegetation.
Third, fire-derived ozone contributes to additional carbon losses. Research in the Amazon identifies an indirect pathway beyond the carbon released directly by combustion.
These findings support the Ozone Feedback Framework’s central argument: ozone can amplify climate change by damaging the vegetation that helps regulate atmospheric carbon.
The next step is to quantify how these effects combine across different ecosystems and how much they influence global atmospheric CO₂ and warming.
7. Why This Matters for Climate Research
Climate change is often discussed as though greenhouse-gas emissions, forests, wildfires, and air pollution were separate problems.
They are connected.
Ozone affects vegetation. Vegetation regulates carbon uptake. Wildfires release carbon and ozone precursors. Drought affects both vegetation health and fire conditions.
Climate and ecosystem models need to evaluate these connections to determine whether they accurately represent the full effects of atmospheric pollution and wildfire on carbon sinks.
Scientists should combine plant experiments, field observations, ecosystem carbon budgets, and atmospheric models to measure the strength of the ozone feedback and its variation across regions.
The goal is not to assume a global warming multiplier before it has been calculated. It is to quantify the observed mechanisms and determine their combined climate consequences.
8. What Can Be Done?
Reducing greenhouse-gas emissions remains essential to limiting global warming. Reducing the emissions that produce ground-level ozone can also protect human health and vegetation.
Protecting forests, reducing deforestation, and preventing destructive wildfires can preserve stored carbon and limit emissions associated with burning.
These actions address connected parts of the same problem: reducing climate pollution while protecting the natural systems that remove carbon dioxide from the atmosphere.
Conclusion: Climate Change Is Weakening Nature’s Climate Regulation
Ozone pollution damages vegetation and reduces the biological processes that remove carbon dioxide from the atmosphere. Research also demonstrates that fire-derived ozone contributes to additional carbon losses in Amazon forests.
These findings establish a significant connection between atmospheric pollution, ecosystem damage, and climate change.
The Ozone Feedback Framework brings these connections together: ozone can weaken terrestrial carbon sinks, while wildfire and drought interact with atmospheric chemistry to intensify ecosystem stress.
The exact global contribution of this feedback remains to be quantified. But the underlying biological mechanisms are documented, and their implications deserve greater attention in climate research.
Climate change is not simply making the planet warmer. It is also affecting the natural systems that help regulate the climate. Ozone is one of the connections we cannot afford to overlook.
Research References
Brown, F., et al. (2026). “Fire-derived ozone intensifies carbon loss in Amazon forests under extreme droughts.” Communications Earth & Environment. https://www.nature.com/articles/s43252-026-04047-0
Fang, Y., et al. (2026). Global meta-analysis of ozone and other climate factors affecting plant gas exchange, biomass production, and allocation. Journal of Plant Ecology. https://doi.org/10.1093/jpe/rtaf213
Brouse, D., & Mukherjee, S. Ozone Feedback Framework. Membrane Institute.