Swiss geoengineering start-up targets methane removal

AMR (Atmospheric Methane Removal) wants to use a fleet of small jets to disperse iron chloride (FeCl3) particles in aerosol form over iron-deficient parts of the oceans. This GeoRestoration Action Plan (GRAP) will see 40-60 jets making multiple flights per day, seeding the atmosphere above the oceans with up to 300,000 tons of ferric chloride per year, at an altitude of 2,000-4,000m.

According to AMR, iron chloride acts as catalyst in the presence of the Sun’s UV rays, converting atmospheric methane into CO2 and water. As methane’s warming effect is many orders of magnitude higher than CO2, the company claims this will have an immediate cooling impact on global temperatures.

FeCl3 particles that reach the oceans or land break down into ferric compounds that can feed plant and algae photosynthesis, sequestering CO2 and boosting the overall cooling effect. It’s claimed that the geoengineering process mimics one that already occurs naturally in iron-rich desert dust clouds.

"All climate change comes from nature, good or bad,” said AMR’s Oswald Peterson in a statement. “All we can do is treat nature well - so she heals the climate we have so massively perturbed.”

AMR’s GRAP has three phases. The first will involve a field test where one plane will distribute small amounts of ferric chloride over the ocean, demonstrating the technology and evaluating its atmospheric impact. If successful, it will provide the basis for the next phase, the fully operational mode that will seek to bring methane levels back to 0.7ppm by 2050. A third phase of the operation will see methane maintained at a sustainable level.

Currently, methane in the atmosphere today is at about 1.9ppm, 2.5 times the pre-industrial concentration. While this is far lower than CO2’s concentration at around 422ppm, methane’s thermal effect is 120 times higher than CO2, so methane contributes about 30 per cent of the current global warming effect.

However, methane’s warming impact is short-lived, as it oxidises naturally in the atmosphere after around 10 years. This means that curbing methane emissions and actively removing it from the atmosphere can have an outsized cooling effect today, potentially stabilising the climate as society gets to grip with CO2 emissions.

AMR estimates the cost of the GRAP at under $10bn per year. Over 20 years approximately 3Gt of methane - equivalent to 360Gt of CO2 - would be removed. It’s claimed this would result in a price of less than $1.00 per ton of CO2e.

AMR aims to generate revenue by selling carbon credits based on these sequestered greenhouse gases. So far, the company has been financed by its shareholders and the support of Dutch organisation Carbonfix, which supports climate tech start-ups at their earliest stages. AMR is now seeking outside investment, though it has stressed that its primary motivation is ‘making a positive climate impact’, and that profit is only considered ‘a secondary objective’.