Record! 2014 was Earth's warmest year

Doyle Rice | USA TODAY

Show Caption Hide Caption Record! 2014 was Earth's warmest year The planet's warmest year on record was 2014, federal scientists announced Friday.

The planet's warmest year on record was 2014, federal scientists announced Friday.

"Humans are literally cooking their planet," said Jonathan Overpeck, an atmospheric scientist from the University of Arizona.

The global temperature from 2014 broke the previous record warmest years of 2005 and 2010 since record-keeping began in 1880.

Two separate data sets of global temperature — from NASA and the National Oceanic and Atmospheric Administration — confirmed the record. Another data set released last week by the Japan Meteorological Agency also found 2014 was the planet's warmest.

The average temperature for 2014 was 58.24 degrees globally, 1.24 degrees above the 20th-century average, NOAA said.

"It just shows that human emissions of greenhouse gases, mainly from the burning of fossil fuels, are taking over the Earth's climate system," Overpeck said. "The data are clear: The Earth is warming, and humans are causing the bulk of this warming."

Record warmth was seen around the world in 2014, including far eastern Russia into western Alaska, the western USA, parts of interior South America, most of Europe stretching into northern Africa, and parts of eastern and western coastal Australia.

The Eastern USA was the main inhabited part of the world with a cooler-than-average year. Overall, the USA had its 34th-warmest year, though several Western states sweltered to their hottest year on record, including California and Nevada.

"A record warm year, especially absent (the warming effects of) a strong El Niño, is mostly a reminder that the long-term trend for Earth's temperature is up, up, up," said Michael Oppenheimer, a Princeton University climate scientist. "The dice are definitely loaded in favor of progressively hotter years, and the odds will increase as long as atmospheric greenhouse gases increase."

The planet has not seen a month with below-average temperatures since February 1985, said Radley Horton, a scientist from Columbia University.

"What we have known for decades is that increasing greenhouse gas concentrations — due to human activities — have stacked the deck dramatically towards more record warm years and fewer record cold years," Horton said.

Marshall Shepherd, a meteorologist from the University of Georgia and 2013 president of the American Meteorological Society, said those younger than 29 haven't lived in a single month where the average was cooler than the 20th-century average.

"That's a new normal that is a result of human activities on top of the natural varying climate that has global temperature trends moving very quickly towards a 1-2 degrees Celsius increase," he said.

The effects of global warming are showing through faster rates of sea-level rise, accelerated melting of land-based ice sheets, rapid loss of Arctic sea ice, more frequent coastal flooding and more frequent and intense heat waves, Horton said.

2014 was a year of climate change reports, including one from the United Nations' Intergovernmental Panel on Climate Change and the release of the National Climate Assessment from the U.S. federal government. Both reports further spelled out in the starkest terms that man-made climate change is a real and ongoing threat.

It was also the year the Environmental Protection Agency announced its Clean Power Plan — which aims to slash carbon dioxide emissions from power plants 30% by 2030 — along with an agreement signed between the United States and China to drastically reduce greenhouse gas emissions.

The next big step for climate change action will probably come in December in Paris at the U.N. Climate Change Conference, where the goal will be to create a legally binding deal on climate change — to which all the world's nations must agree.

"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," Secretary of State John Kerry said in a statement. "The question is when and how the world will respond. Ambitious, concrete action is the only path forward that leads anywhere worth going."

The NOAA/NASA announcement comes the day after a report from the journal Science said humanity has exceeded several "planetary boundaries," including the rate of extinction, deforestation and the amount of carbon dioxide that's in the atmosphere.