Lecture on Global warming: The known, the unknown, and the unknowable

6 Oct, 2006

  • Highlights
  • Agenda

by Professor Jagdish Shukla
Friday October 06, 2006

Professor Jagdish Shukla, Distinguished Professor at the George Mason University and President, Institute of Global Environment and Society, Maryland, USA gave a talk on �Global Warming: The Known, The Unknown, and The Unknowable.� Mr. Kapil Sibal, Union Minister for State for Science, Technology and Ocean Development, chaired the session. Professor Shukla described global warming as a manifestation of the excess carbon di-oxide and methane in the atmosphere. These gases trap terrestrial heat and generate instabilities in climatic conditions. Apart from the changes in the chemical composition of the atmosphere, there are natural variations–better known as hydrodynamic instabilities–that interact with the oceans and forests to produce large fluctuations in the climate from year to year. Global warming affects the equilibrium temperature of the earth. Changes such as a decline in the snow cover in the northern hemisphere, delayed freezing of lakes by at least six days, loss of mass in glaciers and ice caps, increase in temperature of permafrost and frozen areas by 2 to 4 degrees etc can be seen as examples of this phenomenon. Most importantly, he said, global temperature has increased by 0.75 degrees and sea level has been rising by about 2 mm per year for the last 50 years. He therefore emphasized the need to develop sophistica-ted models that would help reduce the uncertainty associated with the determination of global warming and its effects. Professor Shukla reiterated that the ability to make predictions about the weather over a short span of time was constrained primarily by the lack of high resolution models. He emphasized the need to develop scientific manpower and models in India in order to utilize the existing data effectively and bring out the likely impact on Indian agriculture.