The Global Humanitarian Forum certainly attracted some publicity last week when it published a report suggesting that global warming kills 315,000 people each year and seriously harms another 300,000. Total price tag: $125 billion annually.

Such numbers are as appealing to journalists as they are to those who put them out, precisely because they are easy to understand and explain. They should also raise alarms, and for the very same reasons. It’s not that anybody really doubts that global warming is impacting ecosystems and communities and thus affecting lives, but these are complex issues that resist quick attempts at quantification.

The New York Times published a quick story about the report while raising some basic questions about the estimations. The story quotes Roger Pielke Jr., who has been researching these issues for years, calling the report a “methodological embarrassment” that simply glosses over socioeconomic factors (like people moving into hurricane-prone coasts). For an in-depth discussion, check Pielke’s blog.

Although the GHF didn’t shy away from using the eye-catching estimates, the authors do explain their calculations in the report. Among other things, they cite data from Munich Re estimating that 40 percent of the increase in weather-related disasters from 1980 to present is due to climate change. As it happens, Pielke says Munich Re itself has come to the opposite conclusion when it comes to assessing the data and assigning blame.

Pielke’s message appears to be getting out there. Reuters followed up its initial story with a second, more thematic piece raising various questions about this kind of research.