Bio beats fossil

Text Sari Eskelinen I Photos Varpu Heiskanen and Vapo

For the first time in history, experimental research has shown that the gross carbon emissions from bioenergy are smaller than those from energy produced with coal. These emission calculations also consider the emissions resulting from biomass production.

Located in the easternmost province of the European Union, the village of Kovero in eastern Finland has assumed a central role in climate change research. Indeed, a former peat production area in the village was turned into an arable field which has been used for growing reed canary grass for several years now. This same field has been the scene of experimental research into the crop’s biomass production as well as into the gas exchange between the plantation and the atmosphere.

“Research has shown that reed canary grass grown on former peat production areas can be used to reduce carbon emissions into the atmosphere,” says Professor Seppo Kellomäki of the UEF School of Forest Sciences.

Professor Kellomäki and Professor Pertti Martikainen of the UEF Department of Environmental Science are the leaders of a research project addressing bioenergy, climate change and ecosystem carbon cycles in particular. The project brings together the expertise in biogeochemistry of the Department of Environmental Science and the applied research into systems ecology conducted by the School of Forest Sciences, where several models on substance flows and their dynamics have been developed.

However, the measurements conducted in the testing area in Kovero alone are not enough to define the gross carbon emissions of reed canary grass, as the energy needed for the production of fertilizers, soil cultivation, harvesting and transport also needs to be considered. This total carbon balance was defined with the help of the lifecycle analysis model developed in Forest Sciences, which has also brought an ecosystem-level viewpoint into the research.

Reed canary grass as a carbon sink

Bioenergy has long enjoyed strong political support in international climate policy. High hopes have been set for energy produced from biomass in mitigating climate change, despite the fact that there still is very little scientific data on the carbon emissions of bioenergy. Now, however, research has shown that these expectations have not been in vain: the carbon emissions of energy produced with reed canary grass are lower than those of energy produced with coal. There was, nevertheless, some variation in the annual emission levels. In rainy summers, reed canary grass grows rapidly and is more efficient in capturing carbon, thus leading to decreased carbon emissions into the atmosphere.

“In dry summers, the carbon emissions of reed canary grass are at the same level as those of coal; however, in rainy years the energy production is nearly emission-free. Taken to the extreme, the emissions from energy production were lower than the amount of atmospheric carbon captured and stored in the plantation, which means that the whole energy production chain served as a carbon sink. As research proceeded, we understood that reed canary grass was being grown in too dry conditions,” Professor Martikainen explains.

The testing area set up on a former peat mire enabled a more detailed investigation of the phenomenon. Drainage ditches were blocked in order to raise the water level in the testing area.

“This served as a means for us to present practical solutions for improving the climate response of reed canary grass. Our research, however, represents one peat type only, and the results might not be the same in all peat types,” Professor Martikainen points out.

The research has now been expanded to cover also mineral soil, i.e. the soil type commonly found in arable land areas in Finland. Indeed, spring 2009 saw the launch of this project in a research station of MTT Agrifood Research Finland in Maaninka in the province of Northern Savo.

“We examine the behaviour of reed canary grass on normal arable land. It could be hypothesised that normal arable land is less susceptible to carbon loss than carbon-rich peat soil.”

Professor Martikainen points out that environmental issues should be considered, not only in terms climate factors, but in terms of other relevant factors as well. For instance, agricultural nutrient flows have proven to be a major problem.

“An interesting question is whether the growing of perennial bioenergy crops will decrease nutrient flows in high-risk areas, e.g., on the shores of lakes and rivers.”

Comparative data on bioenergy crops

Forest logging residue plays a central role in Finnish bioenergy production, and the carbon emission levels of energy produced with reed canary grass have now been verified through research. In the future, the project seeks to produce comparative data on the suitability of various energy crops for energy production.

“We aim to study the environmental effects of different energy biomasses and to find the best biomass candidates for energy production,” Professor Kellomäki says.

This work, once again, uses the lifecycle analysis used in Forest Sciences on the Joensuu Campus since the 1990s. The very first research projects investigated the phenomenon from the viewpoint
of a single forest or stand. Now, however, it is possible to study even regional-level effects.

“A new aspect in the research is that we are converting the results from the life-cycle analysis to climate effects. This, in turn, is the kind of information climate policy decision-makers need,” Professor Kellomäki remarks.

Thus far, there have only been a few research methods to compare the effects of different forest management strategies on the climate.

“This kind of research enables us to gradually find ways of mitigating climate change,” Professor Kellomäki estimates.

Expertise from China

The UEF research project entitled Prevention of climate change and health hazards in the production of bioenergy was launched in 2007 and, over the years, it has also yielded new careers. With the help of FiDiPro (Finland Distinguished Professor Programme) funding from the Academy of Finland, the project was able to recruit a top expert in the field, Professor Kaiyun Wang from China. Professor Wang works at East China Normal University in Shanghai and his research focus lies in the analysis of carbon balance in ecosystems in particular. Furthermore, he attracted a group of Chinese post-doc researchers and doctoral students with him to Finland.

Professor Wang and his team of researchers specialise in carbon cycles, plant photosynthesis and related modelling. According to Professors Martikainen and Kellomäki, expertise on how carbon is captured in the ecosystem will be increasingly called for in the research project in the future.

“At the moment, this group of Chinese researchers is studying the behaviour of reed canary grass in various climate conditions at the UEF Mekrijärvi Research Station. The experiment studies the effects of different environmental factors on the crop,” Professor Martikainen describes.

In summary, active research into the climate effects of bioenergy continues at the University of Eastern Finland. This research is of great significance, as bioenergy is being strongly promoted in international climate policy.

“When we say that bioenergy is the solution to our problems, we also need to be able to show that it is better than our traditional energy production methods,” Professor Kellomäki says.