Finnish researchers have called for a revision of climate change estimates after their findings showed emissions from soil would contribute more to climate warming than previously thought.
The research, which appears in the February issue of the journal Ecology, shows that "the present standard measurements underestimate the effect of climate warming on emissions from the soil."
The researchers from the Finnish Environment Institute write that, "The error is serious enough to require revisions in climate change estimates."
They add that all climate models currently use soil emission estimates based on measurements received using an erroneous method.
While emissions from soil were known to have a significant influence on climate warming, the researchers say previous studies took into account short-term measurements which gave "systematically biased estimates on the effects of climate change on the emissions."
The Finnish scientists' experiments in boreal forests used radiocarbon measurements and showed that the more abundant, slowly decomposing compounds in soil were more sensitive to rises in temperature.
This showed "carbon dioxide emissions from the soil will be up to 50% higher than those suggested by the present mainstream method," if the mean global temperature rose by the previously forecasted 5°C before the end of the century, and if the carbon flow to soil did not increase.
The institute said a 100% to 200% increase of forest biomass was needed to offset the increasing carbon emissions from soil, whereas previous estimates called for a 70% to 80% increase.
This latest research contradicts a study that appeared in Nature Geoscience in November 2008, which concluded carbon dioxide emissions from soils are overestimated by as much as 20%.
The study, based on various Australian soils, found a much higher proportion of charcoal than estimated by previous models. This meant the amount of CO2 released by the soils is much lower than previously believed.
Either way, the findings have major implications for climate change predictions as annual carbon emissions from soils are estimated to be more than all human-made CO2 emissions combined.