Majorities of people in most countries will achieve middle-class economic status by 2030, but the effects of climate change, an aging global population and anti-government movements in authoritarian nations such as China could cause upheaval in economic and political systems.

The predictions come from a forward-looking study by the National Intelligence Council, which every four years analyzes key trends and projects their implications 20 years into the future.

The United States is likely to remain "first among equals" among world powers because of the legacy of its leadership role and military power, according to the report.

No other global power or international order is likely to replace the United States' primacy, it said, even though in terms of overall power — economic output, population, military spending and investment — Asia will surpass North America and Europe over the next two decades.

For more on this story, click here.

To read the actual report from the National Intelligence Council, click here.