Simulate extreme climatic changes

Many of the climatic extremes that are happening the world over, like
a sudden increase in rainfall or extreme hot or cold climate are part
of climate change, said Surabi Menon, physicist staff scientist at the
Lawrence Berkeley National Laboratory, California.Speaking to The
Hindu here while on vacation at home, Ms. Menon said the subject of
extreme climate is one of the foci of the U.S. Department of Energy in
atmospheric changes.All the greenhouse gases and the aerosols that
contribute to change in climate need to be controlled and it is not
just enough to talk about less carbon-dioxide (CO2) emission, said Ms.
Menon, who is one of the contributing authors to the Working Group I
of the Intergovernmental Panel on Climate Change. The chapter relates
to bio-geochemical sciences in the climate change report.Each gas and
particle is studied separately to make predictions. The dark particles
among aerosols that absorb light are also responsible for differential
distribution of light in an area.How the presence of aerosols has
affected the climate in China is evident in the laboratory as well as
in real time, she said. Changes in the atmosphere sometimes give rise
to extreme climate events, said Ms. Menon."Satellite images show
intense pollution over India and China. There has been a marked change
in climate from 1979 onwards in China".The kind of developmental
activity that is taking place in India would have a factor of four
degree decrease in rainfall by 2030, going by the current rate of
pollution."Ms. Menon simulates climate modules for China and India in
the Berkeley laboratory with the data she procures from various
agencies from the two countries. The Chinese are meticulous in keeping
their data, she said. A lot of data from over a long period had been
analysed for the country, she said.In India, data handling is rather
inconsistent. But of late, there have been some good papers on climate
and atmospheric sciences coming up from various centres of excellence,
said Ms. Menon."We can construct the Earth's climate history with
paleo-climate record. If we put in good data to simulate climate
modules, predicting climate becomes near-accurate", she said. Going by
the current rate of CO2 emission, 60 per cent of what has been
released by human activity on Earth continues to stay in the
atmosphere. Climate predictions are important to the process of
formulating government policies that would help bring down the
greenhouse effect, she said.The polluting activities would otherwise
lead to what is called the tipping point in the Earth's climate that
would happen when temperature goes up by 2 degrees centigrade. As of
now, 2100 is predicted to be the tipping point when the sea-level
rises because of the intense melting of glaciers.

The Hindu, 27th December 2008