Can US presidential candidates answer these 20 science questions

Some of these include stances on nuclear power, protecting the world's oceans, reducing human and economic costs of mental illness

A coalition of US groups representing more than 10 million scientists and engineers published 20 questions today they want every US presidential candidate to answer ahead of November's vote.

The questions range from how to support vaccine science, to defining the scope of America's goals in space, to the candidates' views on climate change and what would they would do about it.

Stances on nuclear power, protecting the world's oceans, reducing the human and economic costs of mental illness, and the controversy over visa programs that allow highly skilled immigrants into the United States also feature in the list, made public by the American Association for the Advancement of Science (AAAS).

"Voters should have a chance to know where the presidential candidates stand," said Rush Holt, chief executive officer of AAAS, which publishes the journal Science.

"We want journalists and voters to ask these questions insistently of the candidates and their campaign staff."

The 56 groups that helped create the list by crowd sourcing the questions has asked for the candidates to answer the questions by September 6.

All are described by AAAS as non-partisan groups, including the National Academy of Sciences, the American Geophysical Union, the American Chemical Society and the Union of Concerned Scientists.

The effort was organised by ScienceDebate.Org, which commissioned a national poll last that found 87 percent of Americans said it was important that candidates for president and Congress have a basic understanding of the science informing public policy issues.