Half of U.S. residents in a new survey expect another country to emerge this century as the world's leader in addressing technological challenges ranging from the economy to global warming.

It's not clear what country would emerge, however, at least insofar as the opinions of the respondents are concerned.

China was cited by 20 percent of respondents as most likely to take the lead, with Japan and Europe (as a group of nations) trailing at 10 percent each, and India at 4 percent.

The survey of 808 adults was carried out Jan. 22-25 by Hart Research Associates and released Tuesday by Duke University.

Some experts, too, are concerned, with speculation dating back to October that the financial crisis would threaten U.S. superpower status. Even earlier — in fact for years now — some have seen the United States in its sunset years as the world superpower. But many analysts challenge that assumption, arguing that there is no single country with the military, economic, political and cultural might to take the reigns. Some analysts believe that superpower status is closely related to technological prowess.

In the new survey, Americans with more education are even less optimistic about the likelihood the United States will be the world's technological leader in the 21st century.

"Americans understand that innovation is critical to their future, but also recognize that our country's continued leadership isn't assured just because we invented everything from the airplane to the personal computer," said Thomas Katsouleas, dean of Duke's Pratt School of Engineering. "The survey shows that when Americans focus on how central engineers are to solving our biggest problems, they come to view the discipline as essential and want to attract more talented young people to it."

The questions about U.S. technology standing were part of a larger survey about major engineering challenges facing the world, according to a statement released by Duke. Respondents gave highest priority to developing better medicines, providing clean water around the world and developing environmentally friendly power sources. They gave less priority to securing cyberspace against attacks or to restoring and improving deteriorating urban infrastructures.

The respondents said the best ways to improve U.S. global competitiveness are with more training for workers, improved K-12 math and science teaching, and tougher standards for public school teachers and students. They were much less likely to endorse tax breaks for business and investment, or new immigration policies to attract foreign engineers and other technical experts.

Some 58 percent said they thought engineering is losing out to other professions when it comes to young people choosing careers. They said this is happening because engineering does not pay as much as other fields, requires extensive schooling and is seen as being difficult, the survey found. "Not as glamorous" was cited least often among seven possible answers in explaining why engineering has been a less attractive career choice.