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Dr. Gary Yohe, an economist at Wesleyan University, calculated that many ecological changes measured in recent decades had a 95 percent chance of being a result of climate warming and not some other factor.

I have a pretty strong economics and statistics education, and I can't fathom how he would have calculated that.

I guess he would have figured the rate and extent of ecological change in some prior "normal" period. Assumed that rates of ecological changes over time are normally distributed, and then measured the more recent rates of ecological change. One could then, using the assumption of normal distribution, say that 'well, the more recent rate is high enought that there is only a 5% chance that it is random, and not the cause of some new factor.'

To do so, you would need to define what a rate of ecological change is, and what the data points are, for some prior period, and then for some current period. Impossible. You would then have to assume that the prior data is "normal". Which is dubious. You would then have to assume that rates of change over time are normally distributed. Also dubious. You would then have to assume that the 5% (the standard) chance did not occur, and that in fact it is the result of an outside factor (probable, but he could be wrong). You then have to assume that the only factor that has changed is climate warming, and not something else.

In short, he is full of crap.

To do so, you would need to define what a rate of ecological change is, and what the data points are, for some prior period, and then for some current period. Impossible.

No, this isn't impossible. It's been done in a number of paleoclimatic/paleobotanic studies. The rate of ecological change can be measured against the rate of climate (temperature) change using fairly direct measures of temperature, such as stable carbon or stable oxygen isotope ratios.

As you note, I think he goes out on a limb labeling the changes as both abnormal AND the result (at least partially) of human influence, but it is possible to compare current rates of ecological change to the rates of change that have occurred in the past.

From the BBC report on this paper: "They say there have been "significant" moves in range averaging 6.1 km (3.8 miles) per decade towards the poles". This number translates to a 0.025 C/decade global warming, which agrees with satellite and balloon observations showing very little recent warming. It suggests the commonly reported surface warming is in error, most likely due to improper treatment of urban heat islands.