Doyle Rice

USA TODAY

The planet sizzled to its third straight record warm year in 2016, and human activity is to blame, federal scientists announced Wednesday.

The last time the world was definitely warmer than today? Some 125,000 years ago based on paleoclimatic data from tree rings, ice cores, sediments and other ways of examining Earth's history, said NASA climate scientist Gavin Schmidt said.

The average temperature across the Earth's land and ocean surfaces in 2016 was 58.69 degrees, a whopping 1.69 degrees above average, according to the National Oceanic and Atmospheric Administration (NOAA). It was largest margin by which an annual global temperature record has ever been broken, NOAA said.

Although less than 2 degrees above average may sound small, it's quite a large number in climate science, where records are often broken by tenths or even hundredths of degrees.

A separate analysis of data from NASA concurred with NOAA's findings. Most of the warming has happened in the past 35 years, and 16 of the 17 warmest years have occurred since 2001, NASA said.

Record high temperatures were set in 2016 on nearly every continent. No land areas were cooler than average for the year. Eight straight months (January through August) were also each the warmest since records began 15 years after the Civil War ended.

The warmth last year contributed to fierce and deadly heat waves in Asia and the Middle East, a "mega"-wildfire in Canada, record low sea ice in the Arctic, and devastating coral bleaching in the Great Barrier Reef near Australia.

The record warmth was 80-90% the result of the long-term climate trend and 10% the result of the natural El Niño climate pattern, Schmidt said.

The warming trend over the past few decades can be linked to the burning of oil, gas and coal that releases "greenhouse" gases, such as carbon dioxide and methane, into the atmosphere. These gases have caused the Earth's temperature to rise over the past century to levels that cannot be explained by natural variability.

“No world leader can afford to ignore these results, which show that people all over the globe are being exposed to increasing impacts of climate change," said Bob Ward of the London School of Economics and Political Science. "Any politician who denies this evidence from world-class climate scientists in the United States will be willfully turning a blind eye to rising risks that threaten the lives and livelihoods of their citizens."

Since the start of the 21st century, the annual global temperature record has been broken five times — 2005, 2010, 2014, 2015, and 2016 — NOAA said.

"Though some years will be warmer than others, the overall trend over multiple decades will inevitably be upward as long of concentrations of carbon dioxide in the atmosphere keep increasing,” said Gerald Meehl, a scientist with the National Center for Atmospheric Research.

Other data sets in the United Kingdom and Japan this week also concurred with the findings from the U.S. agencies.

“The science is clear and headed in one direction," said Lou Leonard with the World Wildlife Fund. "Human-caused changes in climate are putting the lives of both people and wildlife at risk. From disappearing Arctic ice in Alaska to greater storm surges along our nation’s coastlines to heatwaves in America’s heartland, nature is sending a distress call."

Last year was the USA's second-warmest on record, NOAA said last week.

Looking ahead, Schmidt said that 2017 will likely be a "top 5" warm year for the planet.