Mercury pollution surge linked to global deforestation, says MIT

Around 10% of annual human-made mercury emissions are caused by deforestation, a figure which could escalate unless urgent action is taken, says research.

In brief:
  • MIT study reveals 10% of human-made mercury emissions is linked to global deforestation, posing a significant risk
  • The Amazon rainforest is a significant resource, contributing 30% to the global land sink and representing the role of conservation
  • Scientists have urged for strategies to curb the unintended consequences of industrial activity such as farming and mining on the environment.
In detail:

A profound connection has been established between a surge in human-related mercury emissions and global deforestation, in a revelation that challenges previous thoughts on the matter.

The revelatory study found that approximately 10% of annual human-made mercury emissions pumped into the atmosphere can be traced back to extensive deforestation, as outlined by researchers from the Institute for Data, Systems, and Society (IDSS) at MIT.

The planet’s vegetation acts as a ‘sink’ for toxic pollutants by extracting them from the air. For instance, the Amazon rainforest is a significant mercury sink, and contributes about 30% to the overall global land sink.

Therefore, rainforest preservation is critical to combatting mercury pollution because persistent or intensive deforestation could lead to a continual rise in net mercury emissions.

The study underscored the far-reaching impact of deforestation on mercury levels, with Brazil witnessing deforestation emissions accounting for 40% of total human-made emissions. In the paper, the researchers stated that addressing emissions related to deforestation must be an integral component of comprehensive global pollution control efforts.

MIT Department of Earth, Atmospheric and Planetary Sciences, a professor at IDSS, Noelle Selin, advocates for a holistic strategy to tackle the problem.

Selin said: "Policies to protect forests or cut them down have unintended effects beyond their target. It is important to consider the fact that these are systems, and they involve human activities, and we need to understand them better in order to actually solve the problems that we know are out there.”

Mercury, a trace element, becomes a threat when it infiltrates water bodies where it transforms into methylmercury – a potent neurotoxin. Forests, functioning as indispensable providers of ecosystem services, sequester mercury in soils, mitigating the risk of toxic methylmercury accumulation in oceans.

The study asserted that managing this relationship is essential for a comprehensive approach to pollution control.

While global reforestation efforts could enhance mercury uptake by 5%, Selin said they should not replace broader pollution control strategies. Instead, the researchers stressed the need for a nuanced understanding of emissions accounting for different fuels and underline the critical importance of timely action.

Lead author of the study, Ari Feinberg, said: “If deforestation was a country, it would be the second-highest emitting country, after China.

The findings illuminate the urgency of addressing deforestation as a significant player in the global mercury cycle and a potential focal point for future pollution reduction policies.

By examining this previously underestimated facet of mercury emissions, the researchers aim to inspire more work that utilises the relationship between deforestation and environmental mercury levels.

Sign up to the weekly bulletin for more news and insights from AWE International >>  join here