Warmers now say its aerosols? Or oceans? Or the dog ate my really good model?

When billions is funding are on the line–people have to make excuses and talk fast.  

Most people know the Earth is warming. But for the last 15 or so years, the rate of warming has slowed, a phenomenon many scientists are calling the global warming "hiatus."

The stalling rise has given fodder to climate change skeptics and a challenge to scientists.

"The question is what's driving it?" said Norman Loeb, a NASA climate scientist.

On Tuesday, Loeb gave a provocatively titled lecture - "The Recent Pause in Global Warming: A Temporary Blip or Something More Permanent?" - to a packed house at a NASA Langley Research Center auditorium.

His answer was less provocative and reflected the general complexity of climate science.

Changes in solar radiation, water vapor and tiny particles in the air, known as aerosols, probably play a role, he said.

However, a major factor might be an El Nino-like pattern of climate variability that in the past has coincided with slowdowns in global warming.

For example, the rise in global temperatures also slacked off in the 1940s, when the climate pattern known as Pacific Decadal Oscillation was active. That pattern usually lasts 20 to 30 years, Loeb said.

He cautioned against drawing conclusions about what 15 years of slower warming means, mainly because it's a relatively short time period.

"For average climate records, 30 years is like one data point," he said, stressing that while the Earth is warming more slowly, it's still warming.

During the slowdown, the temperature is rising about one-third the rate it had been, he said. The average temperature in the United States has risen about 1.5 degrees since the early 1900s.

Loeb said seeking answers is an exciting challenge:

"It's really forcing us to look at our models and observations and ask questions."

http://hamptonroads.com/2014/08/nasa-scientist-despite-slowdown-earth-still-warming