The year 2014 is on track to be one of the hottest, if not the hottest on record, according to preliminary estimates on Wednesday by the World Meteorological Organization (WMO).
This is largely due to record high global sea surface temperatures, which will very likely remain above normal until the end of the year.
High sea temperatures, together with other factors, contributed to exceptionally heavy rainfall and floods in many countries and extreme drought in others, said the WMO in a press release from its headquarters in Geneva.
WMO's provisional statement on the Status of the Global Climate in 2014 indicated that the global average air temperature over land and sea surface for January to October was about 0.57 Centigrade (1.03 Fahrenheit) above the average of 14.00 C (57.2 F) for the 1961-1990 reference period, and 0.09 C (0.16 F) above the average for the past ten years (2004-2013).
If November and December maintain the same tendency, then 2014 will likely be the hottest on record, ahead of 2010, 2005 and 1998.
This confirms the underlying long-term warming trend. It is important to note that differences in the rankings of the warmest years are a matter of only a few hundredths of a degree, and that different data sets show slightly different rankings.
The high January to October temperatures occurred in the absence of a full El Nino-Southern Oscillation (ENSO).
ENSO occurs when warmer than average sea-surface temperatures in the eastern tropical Pacific combine, in a self-reinforcing loop, with atmospheric pressure systems, thus affecting weather patterns globally.
During the year, sea surface temperatures increased nearly to El Nino thresholds but this was not coupled with an atmospheric response.
However, many weather and climate patterns normally associated with El Nino Southern Oscillation (ENSO) were observed in many parts of the world.
"The provisional information for 2014 means that fourteen of the fifteen warmest years on record have all occurred in the 21st century," said WMO Secretary-General Michel Jarraud.
"There is no standstill in global warming," he said.
"What we saw in 2014 is consistent with what we expect from a changing climate. Record-breaking heat combined with torrential rainfall and floods destroyed livelihoods and ruined lives. What is particularly unusual and alarming this year are the high temperatures of vast areas of the ocean surface, including in the northern hemisphere," Jarraud said.
"Record-high greenhouse gas emissions and associated atmospheric concentrations are committing the planet to a much more uncertain and inhospitable future.
WMO and its Members will continue to improve forecasts and services to help people cope with more frequent and damaging extreme weather and climate conditions," Jarraud added.
The provisional statement was published to inform the annual climate change negotiations taking place in Lima, Peru.
WMO also updated its acclaimed Weather Reports for the Future series, with scenarios for the weather in 2050 based on the Fifth Assessment report from the Intergovernmental Panel for Climate Change, which is co-sponsored by WMO and the UNEP.
Newly added reports are for Peru, France, Vietnam, Spain, Canada and Norway, painting a compelling picture of what life could be like on a warmer planet.
Christiana Figueres, the Executive Secretary UN Framework Convention on Climate Change (UNFCCC) said that "our climate is changing and every year the risks of extreme weather events and impacts on humanity rise." "Fortunately our political climate is changing too with evidence that governments, supported by investors, business and cities are moving towards a meaningful, universal climate agreement in Paris 2015, an agreement that keeps a global temperature rise below 2 degrees C by putting in place the pathways to a deep de-carbonization of the world's economy and climate neutrality or 'net zero' in the second half of the century," said Ms. Figueres.
Average surface air temperatures over land for January to October 2014 were about 0.86 C above the 1961-1990 average, the fourth or fifth warmest for the same period on record.
Western North America, Europe, eastern Eurasia, much of Africa, large areas of South America and southern and western Australia were especially warm. Cooler-than-average conditions for the year-to-date were recorded across large areas of the United States and Canada and parts of central Russia.
Heat waves occurred in South Africa, Australia and Argentina in January. Australia saw another prolonged warm spell in May.
Record heat affected northern Argentina, Paraguay, Bolivia and southern Brazil in October. Notable cold waves were reported in the US during the winter, Australia in August and in Russia in October.
Global sea-surface temperatures were the highest on record, at about 0.45 C above the 1961-1990 average.
Sea surface temperatures in the eastern tropical Pacific approached El Nino thresholds.
They were also unusually high in the western tropical Pacific Ocean, across the north and north-east Pacific as well as the polar and subtropical North Atlantic, southwest Pacific, parts of the South Atlantic and in much of the Indian Ocean.
Temperatures were particularly high in the Northern Hemisphere from June to October for reasons which are subject to intense scientific investigation.
Ocean heat content for January to June was estimated down to depths of 700m and 2000m and both were the highest recorded.