It is often said that the 21st century is the "century of the environment." This means two things: One is that the environmental problems of this planet, especially climate change and global warming, have become so serious that they are attracting more people's attention; and the other is that environmental constraints will serve to trigger technological innovations and economic development.

In other words, technological innovations to overcome environmental constraints will serve as a driving force for economic development in industrially advanced countries in this century.

Shortly after assuming office three years ago, U.S. President Barack Obama announced a set of new proposals that the news media dubbed "Green New Deal." Although this new program appears to have been toned down after Democrats lost badly in the 2010 midterm elections and the American economy plunged into stagnation, its aim still stands.