The title has an "X", as the number of years varies from 10 to 16 depending on who said it and when. I first heard this myth from George Will when he was attacking John McCain's stand on global warming during the 2008 presidential campaign. Mr. Will claimed that the Earth's temperature had not gone up in the last 10 years. When I contacted him for an explanation, he said that it was because 1998 was hotter than any year after that. Strangely, Mr. Will referred to the data from the World Meteorological Organization rather than that from NASA. Mr. Will has no use for the UN, but his statement could only be true if he used the UN data which showed that 2005 was slightly cooler than 1998. NASA's data shows that 2005 was slightly warmer than 1998, and also that 2007 and 2010 were warmer yet. It's a little hard to explain how the Earth reached those higher temperatures without going up, but logic and truth are mostly irrelevant to those who say this.
As the years have gone by, "X" has been increased accordingly and the erroneous statement has been repeated on Skeptic's blogs, newspaper articles, letters to the editor, op-ed pieces, sites like Yahoo!Answers, and by politicians such as Sen. Inhofe. The number "X" is now up to 16 and when I put "no global warming in past 16 years" in Google's search engine, I got 114 million hits. It's a great propaganda piece as it is simple, easily understood, and reduces people's worry about climate change. Unfortunately, it is very comforting, and very, very wrong. The propaganda has been funded, circulated, and promoted by those who do not want us to address global warming as they have an economic interest in the issue.
So what is the truth of the matter? There are number of natural and man-made factors that affect the temperature of the Earth. The main factors are the amount of solar radiation we receive, volcanic activity, greenhouse gases, and ocean circulations such as El Niño and La Niña. Man's main contribution falls in the area of greenhouse gases. We are now emitting 30 billion tons of carbon dioxide each year, and the atmospheric concentration of carbon dioxide has gone up about 40% in the last century. That increase and the ensuing feedback loops are the main factors that can be attributed to man. Though there are other contributions, most of the CO2 increase has come from burning fossil fuels.
Probably the best way to see man's influence on the Earth's temperature is to subtract out the factors that can be attributed to natural sources and to see what is left. That was done very nicely by climate scientist Kevin C. in a video which he produced and posted on YouTube. It's only 2 minutes long, but it shows how the Earth's temperature has responded to the increasing burden of carbon dioxide in the atmosphere.