Methane is one of the most powerful greenhouse gases and is second only to CO2 in its contribution to global temperature increases over the past two centuries. Anthropogenic activities, such as fossil fuel exploitation, livestock production, agriculture, and waste, have been responsible for over 60% of global methane emissions over the last 40 years. To limit global warming to 1.5˚C above pre-industrial levels, significant reductions in emissions are necessary. New research suggests that methane mitigation efforts could play a crucial role in achieving this goal.
A study published in Nature’s Communications Earth & Environment reveals that if global-scale methane mitigation initiatives are implemented before 2030, it is possible to keep global warming levels below 2˚C above pre-industrial levels. However, delaying methane mitigation efforts until 2040 or beyond would increase the risk of exceeding this temperature limit, even if net-zero CO2 emissions were achieved.
The agriculture industry, which is responsible for the largest share of anthropogenic methane emissions, particularly from rice cultivation and keeping ruminant animals like dairy cows, faces increasing pressure to reduce its emissions. Researchers have been exploring various options to tackle methane emissions in the agri-food sector.
One approach involves adding a red alga called Asparagopsis taxiformis (AT) to cows’ faeces. AT contains a compound called bromoform, which can block the production of methane. A study published in Frontiers in Sustainable Food Systems found that adding AT to cows’ faeces reduced methane production by 44%. However, there are concerns about potential side effects due to the high iodine content in AT.
Another method being explored is the use of CRISPR genome editing to modify the microbial communities in cows’ guts. By engineering these microbes to produce less methane, researchers hope to reduce methane emissions from cow burps. The project, funded by TED’s Audacious Project, aims to develop oral treatments for calves to intervene in their microbial systems and reduce methane emissions throughout their lifetimes.
Rice production is another significant source of methane emissions. When soil is flooded during rice cultivation, methane-producing bacteria thrive in the low-oxygen conditions. Researchers have been studying the potential of breeding low-emission rice varieties that can maintain current yields while reducing overall greenhouse gas emissions. By exploiting differences in productivity and root qualities, it may be possible to develop hybrid rice breeds with lower methane emissions.
To achieve low-emission rice production systems, further research into plant physiology is needed, and community buy-in and emissions certification programs could incentivize farmers to adopt these practices.
Overall, these studies offer hope for reducing methane emissions in the agri-food sector and mitigating the impacts of global warming. However, more research and widespread adoption of these strategies are necessary to achieve significant emissions reductions.
