A national report on the state of US science has concluded the United States is still the world leader in science and technology – except by one vital, historic measure.

For the first time, China has overtaken the US in terms of the volume of total scientific papers published – a telling statistic that underscores the rapid strides in scientific achievement China has made on the world stage in recent decades.

"This year's report shows a trend that the US still leads by many S&T [science and technology] measures, but that our lead is decreasing in certain areas that are important to our country," says chair of the National Science Board, Maria Zuber.

"It's critical that we stay at the forefront of science to mitigate those risks."

The biennial Science and Engineering Indicators report is published by the US National Science Foundation (NSF), tracking innumerable markers of scientific achievement and scale across countries (the 2018 online report clocks in at over 1,000 pages).

Among the many statistics reported, China's eclipse of US research output may be of the most concern to those in the American scientific community.

In 2016, China published over 426,000 scientific studies indexed by Elsevier's Scopus database – accounting for about 18.6 percent of the international total. For the first time, the US came in second, notching up 409,000 published papers.

It's not a huge lead, perhaps, and the US output still outranks China when it comes to scoring citations from scientific papers – although neither nation is a global leader on that front.

Sweden and Switzerland produce the most highly cited publications, followed by the US, the EU, and then China.

China's lead over the US in terms of research output isn't across all fields, with different nations offering different strengths.

For example, researchers in the US and the EU produce more papers (and patents) on biomedical science, while China demonstrates a lead in engineering research – as does South Korea.

By financial measures, the US still demonstrates impressive leadership, spending the most on research and development (R&D) - US$496 billion, 26 percent share of the global total - and bringing in the most investment to the tune of almost $70 billion.

But China's not far behind, with its R&D expenditure rapidly swelling by an average of 18 percent annually since 2000 (US was only 4 percent), to where it now commits $408 billion (21 percent of the global total), and scored $34 billion in 2016 in venture capital.

"The actual numbers are breathtaking for the speed with which they've occurred," writes economist Robert J. Samuelson in an opinion piece for The Washington Post.

"China has become – or is on the verge of becoming – a scientific and technical superpower. We should have expected nothing less."

The Science and Engineering Indicators report doesn't offer any insights on how to galvanise the US scientific enterprise and reclaim territory lost to China's gains – but it's pretty clear leadership on science needs to start at the top, and right now, that's not really happening inside the country, or outside of it.

How this will track over the next two years is anybody's guess, but in 24 months the US will receive another report card – and there's a lot riding on those results.

"The US continues to be the global leader in science and technology, but the world is changing," Zuber told Nature.

"We can't be asleep at the wheel."

The report is available on the National Science Foundation's website.