The year 2014 was the warmest in modern record, according to two independent analyses by scientists at NASA and the National Ocean Atmospheric Administration. And, with the exception of 1998, the 10 warmest years in modern record occurred in the 21st century. These results, NASA says, are part of a long-term warming trend that is largely driven by an increase in carbon dioxide emissions, as well as other human emissions, into the atmosphere.
"The globe is warmer now than it has been in the last 100 years and more likely in at least 5,000 years," climate scientist Jennifer Francis of Rutgers University told the Associated Press. "Any wisps of doubt that human activities are at fault are now gone with the wind."
To reach these conclusions, NASA and NOAA analyzed global temperature data. The analyses showed that the Earth's average surface temperature has warmed by 1.4 degrees Fahrenheit (0.8 degrees celsius) since 1880, when records were first kept. That warming, NASA explains, has largely taken place over the last 30 years.
"This is the latest in a series of warm years, in a series of warm decades," NASA Goddard Institute for Space Studies director Gavin Schmidt said in a press release. "While the ranking of individual years can be affected by chaotic weather patterns, the long-term trends are attributable to drivers of climate change that right now are dominated by human emissions of greenhouse gases."
NASA and NOAA's results do not mean that temperatures will keep increasing at a steady pace every year. Because of weather events like El Nino and La Nina — phenomena that warm and cool the tropical Pacific — year-to-year fluctuations will still occur. But it's important to note that 2014's record-breaking temperatures weren't the result of an El Nino event. Indeed, no El-Nino weather oscillations took place that year.
Prior to 2014, the Earth's warmest years were 2005 and 2010. A warm December, reports NBC, is the reason 2014 was able to pull ahead.
Also the sea level rise is accelerating faster than thought
http://www.bbc.com/news/science-environment-30816143The rate at which the global oceans have risen in the past two decades is more significant than previously recognised, say US-based scientists.
Their reassessment of tide gauge data from 1900-1990 found that the world's seas went up more slowly than earlier estimates - by about 1.2mm per year.
But this makes the 3mm per year tracked by satellites since 1990 a much bigger trend change as a consequence.
It could mean some projections for future rises having to be revisited.
"Our estimates from 1993 to 2010 agree with [the prior] estimates from modern tide gauges and satellite altimetry, within the bounds of uncertainty. But that means that the acceleration into the last two decades is far worse than previously thought," said Dr Carling Hay from Harvard University in Cambridge, Massachusetts.
"This new acceleration is about 25% higher than previous estimates," she told BBC News.