Noting that the return from huge investments in developing energy sources was "far from adequate", Prime Minister Manmohan Singh on Wednesday asked scientists and engineers to find alternative sources of energy supply and energy conservation technologies.

Addressing the Indian Science Congress in Chidambaram, he also underpinned the need for the Second Green Revolution to be "more holistic" than the first one, and extend application of science and technology to forest conservation and management and new models of water conservation.

Dr Singh also wanted the management of water resources to be addressed, saying it was the "most important challenge facing mankind."

"India must find alternative sources of energy supply. We will need bio-fuel, solar energy, photo voltaic, nuclear and almost all sources, which do not burden the conventional sources of energy supply," he stressed.

"Our energy security depends strongly upon abilities of the scientific community to provide affordable sources of renewable energy supply," he told the scientists at the meet in Annamalai University in Chidambaram.

Terming energy security as both a managerial and a technological challenge, he said, "We have invested billions of rupees in developing a range of energy sources. However, the return on this investment is far from adequate."

Be it hydel power, thermal, or nuclear power, productivity of investments already made have to be improved, he contended.

"We must also find ways and means to conserve energy. Our scientists and engineers can contribute greatly to the development of energy conservation technologies," he noted.

Asking the scientists to explore the links between greenhouse gas emissions and climate change, he said they must also examine its impact on monsoons.

Dr Singh said there was urgent need to upgrade weather forecasting systems in the country. This could provide substantial benefits for crop prediction, instituting crop insurance systems as well as making available rainfall data even upto the block level, he said.

Observing that investing in science was "not an end in itself", the prime minister said, "Nor was it merely a means to advance knowledge and promote development. It should help inculcate a rational and modern outlook, so that we can address the complex problems we face in a rational and humane manner."

Dr Singh expressed concern over the declining enrolment in schools and colleges in basic sciences.

"The teaching of science and mathematics in our schools ought to be made sufficiently interesting for young people," he said.

In the universities and advanced research institutes too, there were declining standards in scientific research work, he said and suggested introduction of a system of international peer review in the research labs.

Stressing the need to make science research "an attractive career option", Dr Singh said while more and better students should be attracted, "this will not happen unless younger scientists are groomed to take over top positions. Only when students see prospects of early reward and recognition, will they be induced to tread the often lonely and toilsome trail of advanced research."

The prime minister said economic incentives and rewards should be so oriented as to attract more bright students.

While new careers were opening up in the private sector and MNCs were also investing in science research, "we must also ensure that the public sector is also able to attract bright researchers in science and technology."

Observing that a rising population and growing demand for natural resources were leading to the spread of environmentally damaging technologies, Dr Singh said, "We, in the developing world, cannot afford to ape the West in terms of its environmentally wasteful lifestyle. Equally, developed industrial economies must realise that they too must alter their consumption patterns so that so few do not draw upon so much of the Earth's resources. The developing world cannot accept a freeze in global inequity."

Dr Singh said the new environment-friendly technologies being developed "must be shared and made available to all so that our planet is saved."

Stressing that knowledge should be used to find new pathways to growth, he said this should be a shared effect.

"It must be an effort that enables the poor to improve their quality of life, their well-being, their consumption levels without being forced to pay the price for the profligacy and excessive consumption of the rich," Dr Singh said.

He said the income and consumption levels of the poor must rise and along with that "we must find ways to meet the growing demand for goods and services in an environmentally friendly manner."