Preparation for IPCC AR5 Underway, New Insights into Climate Change Projection Released

Researchers from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), the Atmospheric and Ocean Research Institute (AORI) of The University of Tokyo, and the Meteorological Institute (MRI) of the Japan Meteorological Agency released on February 23, 2011, new insights from numerical studies on climate change projections. Their work is expected to contribute to the preparation for the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) to be released in 2013.

For projection of long-term global change, simulation experiments were carried out to estimate "allowable" levels of carbon dioxide (CO2) emissions from fossil fuel use under various scenarios of atmospheric CO2 concentration. In an experiment aimed at limiting the global temperature rise to within 2 degrees Celsius from 1990 level, CO2 emission rate from fossil fuel use has to be "below zero" by the second half of this century, which means that fossil-derived new CO2 emissions need to be completely captured through artificial methods by that time.

The near-term climate prediction using data assimilation techniques demonstrated the possibility of predicting both anthropogenic (human-induced) global warming and natural climate variability. Climate scientists project that although the global warming seems to have been slowing down as a consequence from short-term climate variability over the past decade, the long-term warming trend is expected to continue and may accelerate for the next 10 years.

Projections of global and regional weather extremes revealed future changes in typhoon climatology, including: (1) a decrease in the frequency of typhoon occurrence during the period from July to October (the most active months for typhoons), (2) an easterly shift in storm track, (3) a fewer number of typhoons approaching Southeast Asian coasts, and (4) an increase in storm intensity in terms of maximum wind speed. Researchers plan to conduct further experiments and detailed analysis, which are expected to contribute significantly to IPCC AR5.

The above research activities have been conducted under the Innovative Program of Climate Change Projection for the 21st Century (KAKUSHIN), an initiative launched by the Ministry of Education, Culture, Sports, Science and Technology of Japan.

Posted: 2011/06/21 06:00:15 AM