Record-breaking temperatures scorched the planet last year, making 2014 the hottest in more than a century and raising new concerns about global warming, US government scientists said Friday.

The much-anticipated report by scientists at the National Oceanic and Atmospheric Administration (NOAA) was confirmed by an independent analysis from the US space agency NASA that reached the same conclusion.

"Record warmth was spread around the world," said the NOAA report.

"The globally averaged temperature over land and ocean surfaces for 2014 was the highest among all years since record keeping began in 1880."

For the year, the average temperature was 1.24 degrees Fahrenheit (0.69 Celsius) above the 20th century average, beating the previous record-holding years of 2005 and 2010 by 0.07 F (0.04 C).

Parts of the world that saw record heat included Russia, western Alaska, the western United States, parts of interior South America, parts of eastern and western coastal Australia, north Africa and most of Europe.

Record cold for the year was apparent only in some parts of the eastern and central United States.

Experts said the report offers more evidence that humans are driving global warming by burning fossil fuels that boost harmful greenhouse gases in the atmosphere.

"People are always asking, of course, why do we think this is going on," said Gavin Schmidt, director of NASA's Goddard Institute for Space Studies in New York.

"The data shows quite clearly that it is the greenhouse gas trends that are responsible for the majority of the (warming) trends that we have actually seen," he told reporters.

The research group Climate Central said the odds were one in 27 million that the warming trend -- in which 13 of the hottest 15 years on record have all occurred since 2000 -- could have happened randomly, without human-driven influence on the planet's temperatures.

"What's surprising is that anyone is surprised that 2014 was the hottest year on record. The science has been screaming at us for a long, long time," said Secretary of State John Kerry.

"The question is when and how the world will respond. Ambitious, concrete action is the only path forward that leads anywhere worth going."

- Land and sea -

Globally averaged sea surface temperature was the highest ever, at 1.03 F (0.57 C) above the 20th century average.

Land surface temperature was 1.80 F (1.00 C) above the 20th century average, marking the fourth highest in history.

Sea ice continued to decline in the Arctic, depriving polar bears of habitat and driving global warming changes that are felt in distant corners of the world.

The average annual sea ice extent in the Arctic was the sixth smallest in the 36 years that experts have on record.

Meanwhile, sea ice in the Antarctic reached record highs for the second year in a row.

December also broke records, with the highest combined land and ocean average surface temperature for any December in modern history.

- Call to action -

"It's particularly striking that we set a global temperature record," despite a lower than expected effect from El Nino, an ocean condition that brings warmer weather, said Brenda Ekwurzel, a senior climate scientist at the Union of Concerned Scientists.

"Long-term, we can expect this record to be broken again and again," she said.

Environmentalists said the report should serve as a call to action.

"The record temperatures last year should focus the minds of governments across the world on the scale of the risks that climate change is creating," said Bob Ward, policy and communications director at the Grantham Research Institute on Climate Change.

He called for an international deal "to strongly reduce greenhouse gas emissions, to be reached at the United Nations climate change summit in Paris in December 2015."

In the meantime, Schmidt said there are things people can and should do in their everyday lives to turn the tide.

"There are things that people individually can do to reduce their carbon footprint, like having better appliances, driving less, walking more, biking. I try and do those things," he said.

"This is an issue that is not going to go away."