A thermometer shows the temperature in Qibao old town in Minhang district exceeding 50 C July 24, 2016. File photo: IC

Last year's global average temperature was the hottest on record, marking the third year in a row global heat records have been shattered, according to reports published Wednesday by two US government agencies.

The agencies bolstered the scientific conclusion that our planet is getting warmer.

CLEAR TREND

Data from the US National Oceanic and Atmospheric Administration (NOAA) showed that in 2016 the average temperature across global land and ocean surfaces was 1.69 degrees Fahrenheit (0.94 Celsius) above the 20th century average of 57.0 degrees Fahrenheit (13.9 Celsius).

"This was the highest among all years in the 1880-2016 record, surpassing the previous record set last year by 0.07 degrees Fahrenheit (0.04 Celsius)," the NOAA report said.

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

In a separate analysis of global temperature data, scientists from the US space agency NASA also found 2016 to be the warmest on record, a finding also confirmed by the World Meteorological Organization and other agencies.

Last year "is remarkably the third record year in a row in this series," said Gavin Schmidt, director of NASA's Goddard Institute for Space Studies, "We don't expect record years every year, but the ongoing long-term warming trend is clear."

According to NASA, most of the warming occurred in the past 35 years, with 16 of the 17 warmest years on record occurring since 2001.

PERFECT RECIPE

The announcements by NOAA and NASA are something that can be expected, since the first eight months of the year had record high temperatures for their respective months.

"That 2016 was the hottest year on record comes as no big surprise," said Professor Dave Reay of the University of Edinburgh. "The combination of a strong El Nino event with human-induced climate warming was the perfect recipe for another record-breaker."

A strong El Nino event, which warms the upper tropical Pacific Ocean, was in effect for most of 2015 and the first third of 2016, but experts believed that it only played a small role last year.

Deke Arndt, climate monitoring chief at NOAA's National Centers for Environmental Information, told reporter on a conference call that last year's El Nino event may "have contributed a quarter to a third" of the warming, while Schmidt estimated about "10 percent."

The long-term warming trend means that 2017 will likely be another very warm year globally, despite the presence of "a very mild La Nina," which cools the upper tropical Pacific Ocean.

"It's still going to be a top five year in our analysis. I'm pretty confident about that," said Schmidt. "But it's unlikely to be another record year."

RECORD WARMTH EVERYWHERE

During the final month, the December combined global land and ocean average surface temperature departure from average was the third highest on record for any month in the 137-year record. Only the Decembers of 2014 and 2015 were warmer.

Overall, record warmth was observed around the world in 2016, including Far East Russia, Alaska, far western Canada, a swath of the eastern United States, much of Central America and northern South America, and southern Chile.

Much of eastern and western Africa, north central Siberia, parts of south Asia, much of southeast Asia island nations and Papua New Guinea, and parts of Australia, especially along the northern and eastern coasts, also experienced record high temperatures.

No land areas were cooler than average for the year, the NOAA report said.

In the sea, the estimated average annual sea ice extent in the Arctic was about 10.15 million square kilometers in 2016, the smallest annual average ever recorded and continuing a trend of decline seen in recent years.

In Antarctica, the annual sea ice extent was the second smallest on record, behind 1986, at 11.16 million square kilometers. Both the November and December 2016 extents were record small.

Higher above Earth's surface, separate analyses, drawn from both satellite and weather balloon observations, found that 2016 was the warmest year on record for the planet's lower troposphere, which represents roughly the lowest eight kilometers of the atmosphere, and its middle troposphere, the layer between roughly three to 10 kilometers above the surface.

Satellite analyses found that 2016 was the coolest of the 38-year record for the lower stratosphere, the layer of the atmosphere between roughly 13.5 and 21 kilometers above the surface.

WARNING SIREN

The NOAA and NASA reports came just two day before the inauguration of President-elect Donald Trump, who has called climate change a "hoax" and has threatened to pull the US out of the Paris Agreementthat took effect last year.

Specially, a senior Trump advisor has reportedly said the new administration wants to eliminate all climate change research done by NASA as part of its efforts to crackdown the so-called "politicized science."

In an article published in the highly regarded research journal Science recently, outgoing US President Barack Obama warned Trump against walking away from the Paris Agreement and predicted that without further action, the world could see a rise in average global temperatures by four degrees Celsius.

"The decisions we make in the next few years will significantly shape the trajectory of our efforts toward a zero-carbon economy," Lou Leonard, senior vice president of climate and energy of the World Wildlife Fund, said in a statement.

"America's safety, health and prosperity is contingent on remaining a part of the Paris climate agreement and an active player in overall international efforts to address climate change," said Leonard.

Professor Mark Maslin of the University College London said the idea of a pause or a hiatus in global warming "must now be abandoned" with the announcements that 2016 was the warmest year on record.

"Climate change is one of the great challenges of the twenty first century and shows no signs of slowing down," Maslin said. "The hottest year on record is such a clear warning siren that even President-elect Trump cannot ignore."