Delivering the Srimathi Rukmini Lakshmipathy Endowment Lecture at the Women’s Christian College here on Wednesday, he said energy, water, health, land and food are to be considered in a comprehensive, inter-linked fashion for sustainable options. The world’s electricity requirement is likely to double by 2050 and triple by 2100. It is therefore important to explore different sources of energy such as wind, geothermal resources, solar power and ocean energy, Dr. Baldev Raj said, adding, On the issue of climate change, he said it threatened to deprive under-privileged sections more than those who are well-off. Principal Ridling Margaret Waller said that Srimathi Rukmini Lakshmipathy was an illustrious alumnus of the institution. She was a freedom fighter and social reformer. Head of the Chemistry Department Vanaja Muralidharan spoke.