Global Warming - The Blame Is not with the Plants

International scientific team reacts to misinterpretation of their research results and provides the correct perspective

In a recent study (Nature, 12 January 2006), scientists from the Max Planck Institute for Nuclear Physics, Utrecht University, Netherlands, and the Department of Agriculture and Rural Development for Northern Ireland, UK, revealed that plants produce the greenhouse gas methane. First estimates indicated that this could account for a significant proportion of methane in the atmosphere. There has been extended media coverage of this work with unfortunately, in many instances, a misinterpretation of the findings. Furthermore, the discovery led to intense speculations on the potential relevance of the findings for reforestation programs in the framework of the Kyoto protocol. These issues need to be put in the right perspective.

The most frequent misinterpretation we find in the media is that emissions of methane from plants are responsible for global warming. As those emissions from plants are a natural source, they have existed long before man’s influence started to impact upon the composition of the atmosphere. It is the anthropogenic emissions which are responsible for the well-documented increasing atmospheric concentrations of methane since pre-industrial times. Emissions from plants thus contribute to the natural greenhouse effect and not to the recent temperature increase known as ‘global warming’. Even if land use practices have altered plant methane emissions, which we did not demonstrate, this would also count as an anthropogenic source, and the plants themselves cannot be deemed responsible.