That’s the inference from this article. The original global climate data compiled in the 1980s seems to have been lost. Adjusted data remain, but the adjustment methods apparently aren’t fully documented.
I doubt that this development is going to change anybody’s mind, especially because it originated in National Review. But it will be interesting to see whether it even gets much media coverage.
… or so it would appear from this slashdot article. ( The original source is here, but that link doesn’t appear permanent.)
The problem arose from a malfunction of the satellite sensor we use for our daily sea ice products. Upon further investigation, we discovered that starting around early January, an error known as sensor drift caused a slowly growing underestimation of Arctic sea ice extent. The underestimation reached approximately 500,000 square kilometers (193,000 square miles) by mid-February.
I would let our friends at Heartland Institute know about this, but apparently they’re still trying to figure out that California isn’t New Mexico. On January 29 I let them know of their error; as of February 19 it remains on their site.