"How does the observation that March 2008 was the second-warmest all time..." Complete baloney! Your post the other day stated that in the USA March was the 63rd warmest in the past century. That's cold. As for the temperature data set for the rest of the world NOT matching the trend in the USA for March I call it suspect.
Now that we have the Argo network in the oceans and the Aqua satellite the truth is being shown and that is the Earth is cooling.
Your post the other day stated that in the USA March was the 63rd warmest in the past century. That's cold.You've got to stop being so parochial. The United States is approximately 2% of the world's surface area. North America is probably 4-5%.
Clearly, the U.S. and North America were particularly colder than normal. Find another place with a significant surface area that was particularly colder than normal.
Bing! Bing! Bing! Winner! The Pacific -- where La Nina is still holding on.
If you want to know why March is a significant "bellwether" month, see post 21.