With respect to insect pests, the situation is considerably more complex. Recent reviews by Lindroth demonstrate just how difficult it is to draw bottom-line conclusions in this area. Changes are bound to occur, however, with some insects faring better than others; and as a group, insect populations will probably increase.
In two major reviews of plant-animal interactions in both terrestrial and aquatic ecosystems, for example, the total biomass of insects and other plant-eating animals was invariably seen to rise with an increase in ecosystem vegetative productivity. Consequently, percentage crop destruction due to insect damage will probably be little altered by future increases in the air's CO2 content.
More vegetation will thus be eaten by crop pests; but more will also be left to be harvested.
** For additional peer-reviewed scientific references and an in-depth discussion of the science supporting our position, please visit Climate Change Reconsidered: The Report of the Nongovernmental Planel on Climate Change (www.climatechangereconsidered.org), or CO2 Science (www.co2science.org).