This earth work in the Great Salt Lake near Rozel Point in Utah was built in 1970 by Robert Smithson near the end of a cyclical drought period. The drought ended soon after and the earthwork spent the next 3 decades submerged. It became visible again in 1999 but has since partially submerged again due to heavy winter snows in the mountains that feed the lake.

The decades long wet/dry cycles of the area have been going on for eons. Much of the western US is affected since a main driver of the cycle is similarly long period sea surface temperature cycles in the Pacific ocean. There are other cyclical variations such as the track of upper atmosphere winds. The cycle of sea surface temperatures and wind tracks interact to either amplify or counteract one another, providing great variability to resulting conditions. It can be very wet, very dry, or anywhere in between though the dominant pattern is decades of drought followed by decades of rain.

There are other effects than variable lake levels that hide or reveal art works.

Almost seven times more forested federal land burned during the 1987-2003 period than during the previous 17 years. In addition, large fires occurred about four times more often during the latter period.

Seventeen years before the beginning of the 1987-2003 period Smithsons sculpture was visible, but not for long. A wet period began that lasted about until 1987. By 1999 years of drought had lowered the lake enough to reveal it again. Not only do lakes rise and fall, forests burn too. But hey, this could be blamed on climate change if you squint a bit.

The new finding points to climate change, not fire suppression policies and forest fuel accumulation, as the primary driver of recent increases in large forest fires.

"I see this as one of the first big indicators of climate change impacts in the continental United States," said research team member Thomas W. Swetnam, director of the Laboratory of Tree-Ring Research at The University of Arizona in Tucson.

"We're showing warming and earlier springs tying in with large forest fire frequencies. Lots of people think climate change and the ecological responses are 50 to 100 years away. But it's not 50 to 100 years away -- it's happening now in forest ecosystems through fire."

The researchers found the wildfire season is now starting earlier, fires are lasting longer and the fire season is ending later.

"The length of the fire season has increased almost two-and-one-half months compared with 1970 to 1986," Swetnam said. "That's a remarkable thing in itself."

What a muddled mess.

The west is droughty in cycles. It always has been. We have written records that go back a few hundred years to the time of the Spanish missions, and proxy data from tree rings and such that goes back much further.

Western forests burn. They always have done. Some of the trees and brush are adapted to fire and require it for seeds to germinate so forests can regenerate. For 10,000 years or so humans gave nature an assist, starting fires to achieve their objectives when lightning didn't get it done.

The climate is beginning to change, we think, or will do so soon.

All of these things affect forests. The current condition of the forests isn't natural since there have been timber harvests and fire supression. The net effect of all of these drivers is that forests burn more often and more furiously. Management needs to adapt to this reality.

Also see this exchange between Roger Pielke Jr. and a journalist.

. . .Pielke said it would be easy to overinterpret the study, because the International Panel on Climate Change notes that 35 years is a "pretty short time frame for attribution of any trend to human-caused climate change, and I would think that is especially the case for a complex issue like forest fires."

But a Montana scientist said there simply weren't careful measurements of fires in the years before 1970.

"You really can't make a very accurate evaluation from such a weak data set," said Steven W. Running, a University of Montana ecology professor, speaking of the pre-1970 data. "When Tony Westerling was building the wildfire database, he felt that 1970 was as far back as the data quality would go. "I sure find the trends that were shown to be quite compelling," he said.

This seems so silly, so unscientific. We have long known that there is great cyclical variability. The lack of data is not an excuse for knowingly drawing conclusions that can't stand minimal scrutiny.