Most plans to combat climate change are about reducing carbon dioxide, usually by reducing human emissions.
But the unconventional new idea could actually slow down the pace of global warming by putting it more carbon dioxide in the atmosphere – while removing the more powerful gas that warms the planet.
In a comment published on Monday in the journal Sustainability of natureA group of experts on climate and chemistry said that methane should be more focused on combating climate change. Methane remains much shorter in the atmosphere than carbon dioxide but is much more powerful gas that warms the climate as it lasts.
Capturing atmospheric methane and converting it to less powerful carbon dioxide, using special materials and chemical catalysts, can be one of the ways to reduce greenhouse gas enrichment potential, the authors say.
The idea is not a substitute for emission reductions, said chief commentator Rob Jackson, climate scientist and environmental scientist at Stanford University.
"It's the smartest to keep methane and carbon dioxide in the atmosphere," he said. "Only emissions are still rising and we have to think about other tools and approaches to fighting climate change."
Reducing Greenhouse Gases from the Atmospheres, with the reduction of emissions entering it, has long been discussed among climatic scientists and activists. But, by that time, it mostly focused on carbon dioxide.
The idea is usually focused on sucking CO2 from the air, then store it by not returning to the atmosphere – a process known as "negative emissions". The net result would be a lower total carbon dioxide concentration in the atmosphere.
Scientists have suggested different ways to do this, from the enormous woods of carbon-plunging, naturally absorbing carbon dioxide to special machinery that emit CO2 directly from the air. In the latter scenario, captured carbon dioxide would have to be permanently stored somewhere, probably by being injected deep into the Earth.
There was much less focus on capturing methane, probably because the process technically tends to capture carbon dioxide. But scientists have some ideas on how this can be done.
The new comment suggests a promising approach involving the use of porous minerals called zeolites. Scientists already use zeolites to capture methane and convert to methanol, an alcohol that can be used in chemical raw materials or other industrial applications.
It is not much more chemically complicated to convert methane into carbon dioxide, Jackson stressed. Once conversion is completed, the most effective action would be simply to release carbon dioxide back into the atmosphere. This means that more CO2 ends up in the air, but since it takes up a stronger greenhouse gas, the current effect is to reduce global warming.
At present, the concentration of methane in the Earth's atmosphere floats around 1,866 parts per billion. Before the industrial era, when human emissions of greenhouse gases began to increase, methane levels were closer to 750 ppb.
By restoring the atmosphere to pre-industrial methane concentrations, some 8 billion tons of carbon dioxide could be produced in the conversion process, Jackson and colleagues say. It is equivalent to the current global carbon emissions of several months. At present, the world emits about 40 billion tons of carbon dioxide each year.
"It's not trivial, but it's not a break," Jackson said.
Since the concept at this time is almost entirely hypothetical, it is difficult to sketch all the conditions that would be needed to develop and bring to the scale.
When it comes to direct carbon capture in the air – its closest existing analogy – the costs of introducing technology and the challenges for market development are some of the biggest obstacles. Experts have pointed out that federal incentives might be needed by corporations to consider it worth investing in technology. That could mean everything from carbon tax to carbon offsets.
It is also likely to be worthwhile for methane conversion, suggesting authors of a new comment, pointing out that "the price for carbon emissions or the policy mandate is needed" to make the process economically attractive. However, according to such a scenario, they note that capture of methane could become even more attractive than carbon capture – the price of methane would probably be higher because it is a stronger greenhouse gas than carbon dioxide.
These are all the details that need to be discussed. For now, the idea is just a concept – but that's what some experts say would potentially add a new weapon tool to climate change weapons.
"We should look at the options for removing all the major greenhouse gases," said David Victor, a climatic and energy policy expert at the University of California, San Diego. After CO2, methane is the next leading candidate. "
Printed from Climatewire with permission from E & E News. E & E covers important energy and ecological news on www.eenews.net daily.