All approaches to the comparison of disparate environmental effects suffer in common from several intractable problems. Difficulties are posed by the obscurity, complexity, uncertainty and unquantifiability of many effects. Incommensurate indices and discrepant frames of reference exacerbate the analyst's predicament. Although increasingly influential, the monetary valuation literature tends to neglect these problems. Important recent valuation studies are found to be partial in scope, mutually inconsistent and misleadingly presented. The theoretical framework of valuation is itself argued to be profoundly flawed, being unidimensional, sociocentric and opaque in character. It is concluded that there exist preferable and more effective analytical options.