Arctic Geochemical Cycle Research Group
Finding the Current Status and
Trends of the Arctic Environmental Change
Although it is well known that carbon dioxide (CO₂) is the main cause of global warming, in fact various other substances are also involved in global warming.
In particular, the effects of methane and black carbon are estimated to be important.
Methane is the main constituent of natural gas; it is emitted in the burps of cattle and other animals, and also from rice paddies. In Siberia, where in recent years the permafrost is thawing because of global warming, it is possible that methane trapped within the permafrost will be released.
Black carbon, which is an aerosol with a large impact on global warming, is the soot arising from fossil fuel combustion and forest fires. Black carbon itself absorbs sunlight; when it attaches to snow while being carried by the wind, it turns the snow black so that the formerly white snow more readily absorbs sunlight. As a result, especially in cold regions the ground is warmed and its temperature rises, which in turn further spurs on global warming.
Although we know that methane and black carbon have large impact on global warming, there is a large uncertainty. In this context, conducting studies and research mainly in the Pan-Arctic region, where global warming is proceeding faster than anywhere else on the Earth, may provide clues for understanding the connection of methane and black carbon with global warming.
Our Arctic Geochemical Cycle Research Group collaborates with research teams in Japan and other countries to conduct measurements in various locations and investigate atmospheric methane and black carbon. How do these substances arise in the atmosphere, how are they transported, and how do they deposit? One of our current tasks is to build a more precise simulation model. For example, black carbon is actually composed of particles that differ greatly in size and shape. How do differences in particles affect the differences in movement and transport route in the atmosphere? We will use the observation data we are starting to collect and our simulation technology to create a more accurate model.
Research institutions around the world are running simulations to predict global climate change; however, in answer to questions like “How high will global temperatures have risen 100 years from now?” there are wide differences in the results of these simulations.
Further, these models as yet do not sufficiently include the interchange of substances such as methane and black carbon with the atmosphere, oceans, snow, and ice. Refining the models for these substances should increase the precision of global climate change predictions.
When Arctic Ocean ice melts in the future and ships sail that ocean, the black carbon emitted by those ships will likely be a problem. It is our intent to use the findings of our research in the Pan-Arctic region to provide grounds for scientific decision-making to help consider the connection of methane and black carbon with global warming.