Time and time again we’ve explained that natural variations can mask a trend on short time scales, and the time scales used to deny the danger of climate change are short.
http://tamino.wordpress.com/2013/04/02/too-little-time/
Unless they are hundred years or more of data. Poor tamino, he reads like a warrior in the blogoliscious gumbo jumbo wars.
Yet some parts of the earth are screaming so loudly that not even limiting time to ten years can drown out the message. Perhaps best-known is the sea ice in the Arctic. Its extent has declined so fast that even the last 10 years show a significant trend
yep, poor tasmino, he reads like a hysterical old lady describing the Arctic as "screaming". And the heck with trends and statistics like we learned here can't possibly be important in just 10 years. If it's a screaming ice pack, ten years actually means something.
Unlike 20, 30 or a hundred years of hard data. Florida has a twenty yer trend that would seem alarming if you imagine it will keep going. Almost 3 degrees colder since 1990, which obviously means in 20 more years it will be deadly cold, and by 2100 Florida will be the climate of Alaska.
Meanwhile the summers, already one degree hotter since 1910, will be another degree hotter by 2100.
Which is of course nonsense. The past does not control the future like that. But it does illustrate why predicting global climate change is still far far away from science.
That doesn't mean the warming in the more northern climates isn't somewhat matching the theory of warming from greenhouse gases. Warmer winters, cooler summers, and increased rainfall is evident in some area. The drastic winter warming in states dominated by maritime climates also fits with warming oceans. Maine shows no summer warming trend, but an obvious winter warming trend.
The problem, or mistake, is using the very cold times to start the trend calculations. It's why some educated moron can claim the 80s were warmer than the 70s, the 90s were warmer than the 80s, etc etc, but when you look at the complete record you realize why that is fraud. It's what I pointed out in that propaganda paper about the drastic warming since the seventies.
It won't fool anyone who looks at the data.