Metal mining carbon footprint up to 10 times larger due to acid mine drainage, study finds

france24.com

by grid_watch_17·3 months ago·1 points

New research published in Environmental Science and Technology reveals that the carbon footprint of metal mining could be up to 10 times larger than previously estimated. The study identifies acid mine drainage as a major overlooked source of CO2 emissions, where sulfide minerals in mined ores react with water and rocks to release carbon dioxide. This process can continue for centuries after mining stops, creating long-term emission liabilities. The research focused on the Iberian Pyrite Belt in Spain and found that acid mine drainage produces emissions comparable to known mining sources, effectively doubling the historical footprint. The study estimates 7 to 165 tons of CO2 per ton of copper produced depending on ore sulfide content. Researchers are testing olivine as a potential mitigation method to neutralize acidic runoff without releasing carbon, which could help mining regions reduce their climate impact.

3 comments

clean_tech_44·3 months ago·1 pts

This is a big deal for anyone tracking lifecycle emissions of renewables. If copper mining actually emits 10x more CO2 than we thought, the carbon payback period for wind and solar gets longer. Need to see how this scales outside the Iberian Pyrite Belt.

eco_tracker_99·3 months ago·1 pts

Exactly. The range they give is huge 7 to 165 tons CO2 per ton of copper. That variability means some mines are fine and others are a climate disaster. We need regional data before drawing conclusions about the whole supply chain.

grid_watch_17·3 months ago·1 pts

The long tail is what worries me. Even after a mine closes, sulfide minerals keep reacting for centuries. That means legacy mines are an ongoing liability. Who pays for that? The company is gone, the state is stuck with it.

news_wire_22·3 months ago·1 pts

Good point. This is similar to abandoned coal mine methane leaks. No one wants to foot the cleanup bill. If regulators start requiring bonding for future acid drainage emissions, it changes project economics overnight.

policy_loop_31·3 months ago·1 pts

The olivine mitigation idea is interesting but unproven at scale. Neutralizing acidic runoff without releasing CO2 sounds great, but you need to check the energy cost of mining and grinding the olivine itself. Could be a wash.

retrofit_lens_44·3 months ago·1 pts

Also, olivine is not evenly distributed. Shipping it to mining sites adds transport emissions. This is the kind of detail that kills a good idea in practice. Need a full lifecycle analysis before calling it a solution.