The trend accelerated last year and has continued through the first two months of 2016. Experts say the trend is an urgent call for politicians to quickly ratify the climate change accord reached in Paris in December.
Global warming is advancing at an "unprecedented" rate, with sustained measurements of record-setting temperatures, according to the UN's World Meteorological Organization (WMO).
The trend accelerated last year - fed by the El Nino weather phenomenon - with record land and sea surface temperatures, continued sea-level rise, diminishing sea ice and the continued proliferation of extreme weather events across the globe.
"The alarming rate of change we are now witnessing in our climate as a result of greenhouse gas emissions is unprecedented in modern records," said the WMO's new chief, Petteri Taalas.
Dave Carlson, head of the WMO-co-sponsored World Climate Research Program, said the rising temperatures this year were especially alarming.
The "startlingly high temperatures so far in 2016 have sent shockwaves around the climate science community," he said.
Evidence of dramatic warming
The US agency determined that last month was the warmest February since modern records began, with an average temperature that was 1.21 degrees Celsius (2.18 degrees Fahrenheit) above the 20th-century average.
The rising temperatures were especially acute in the far northern climates, where Arctic sea ice was at a record low for February.
That is "quite a dramatic indication of climate change," Taalas told reporters in Geneva. "We have never seen such an event before."
More bad news is that carbon dioxide concentrations in the atmosphere exceeded 400 parts per million (ppm) during the first two months of the year, according to the WMO - an increase of 43 percent from levels prior to 1750, often considered the start of the industrial revolution.
To meet the goal of limiting the global temperature increase to 2 degrees Celsius, experts believe CO2 levels need to be capped at 450ppm.
So far only three Pacific island countries - the Marshall Islands, Fiji and Palau - have ratified the Paris climate accord.
"Our planet is sending a powerful message to world leaders to sign and implement the Paris Agreement," Talaas said, "before we pass the point of no return."
bik/msh (AFP, Reuters)