CHENNAI: In their attempt to predict the impact of climate change in the future, scientists from Anna University are now seeking help from the Stone Age. Based on the study of fossilised remains at archaeological sites around the city, geologists from the Centre for Climate Change and Adaptation Research are collating data on the climate and vegetation that prevailed here 200,000 years ago.
"We can study climate change over the years through a variety of proxies. Palynomorphs (particles between five and 500 micrometres in size found in sedimentary rocks) such as pollen and spores help us understand the vegetation of that period. Dendrochronology (study of annular rings in trees) can help us go back in time and corroborate our findings with carbon isotopes. We can study sea-level changes through corals. We have also looked at animal teeth to study the past. Since they are made of calcium phosphate, oxygen isotopes can be used to understand the animals' dietary habits. This will, in turn, indicate whether they were eating C3 plants, for instance, which grow in wetter conditions or C4 type of vegetation that survives in water-starved areas," said Dr Hema Achyuthan, assistant professor, department of geology.
This collection of statistical data starting from the Stone Age could be used to develop a warning system to monitor the progression of climate change, Dr Achyuthan said. "Now we use regional climate models (mathematical representation of a climate system capable of simulating its behaviour under present and altered conditions) which are made up of parameters like precipitation, monsoon circulation pattern, soil salinity to understand the impact of climate change. However, we need to use as many parameters as possible to make the models robust so that there is very less room for error. This is where the data will help," she added.
Dr A Ramachandran, director, Centre for Climate Change and Adaptation Research, added that they were working with The Met Office Hadley Centre, the foremost climate change research centre in the UK, to downscale global climatic projections to regional levels. "Everyone is talking about the international picture but I want to know how it will affect Tamil Nadu. Once we get the required information, we will then add local parameters to calculate how climate is likely to behave in this region. The information can be used for agriculture, to consevere biodiversity and for the management of natural resources," he said.
