New Research Indicates Carbon Buildup Does Not Cause Sudden Climate Change

A research report published in the web by Nature Geoscience in June indicates that building of carbon dioxide over atmosphere will not bring in sudden changes in climate. The research work, funded by the U.S. National Science Foundation and the Norwegian Research Council, was authored by researchers from the Bjerknes Centre for Climate Research in Norway, UNI Research in Norway and UW.

The research presents evidence of recent studies to indicate that sudden changes in climatic conditions are due to changes in ocean circulation distinctively connected with ice ages. According to Davit Battisti, atmospheric sciences professor from the University of Washington and a member of the research team, there is no geological record to show that greenhouse gas emissions caused abrupt climate changes.

The researchers deployed a numerical climate model along with an oxygen-isotope model to evaluate the reasons that caused climate shifts by utilizing computer generated sequences that imitated Heinrich events of the last ice age, which happened 110,000 to 10,000 years before. The events showed large numbers of North Atlantic Ocean icebergs that had cracked off from glaciers.

The simulations used by the researchers demonstrated that abrupt rise in North Atlantic sea ice cooled the Northern part of Hemisphere, which includes the land places of Indian Ocean such as India, which has resulted in reduced level of rain fall over the region and weakened the Indian monsoon.

Battisti clarified that smooth withdrawal of sea ice will induce quicker warming in places that are within 1,000 kilometers of the ice and said that the warming will slowly dry the semi-arid areas and cause fires. He also noted that the impact of the changing climate could be sudden while it is not so with CO₂ provoked climate change.

He further said that previous researches on carbonate deposits collected from caves in India and China has shown increased monsoon activity by the ratio of specific oxygen isotopes. The modeling utilized by the scientists for the current study replicated the ratios generated by isotope, which enabled the researchers to conclude that the Heinrich events are the root cause for the abrupt changes in the rainfall concentration in India than in other places in East Asia.

Source: http://www.washington.edu/