When fossil fuels are burned, they produce ________________, the main greenhouse gas responsible for global warming trends. 
 Use the word bank below to answer the questions that follow:
 landfills 
 limiting factor 
 nonpoint source
 habitat destruction 
 stop
 migration 
 biodiversity 
 carbon dioxide
 reverse
 carrying capacity 
 commensalism 
 selective cutting
 extinction 
 adaptation 
 ozone layer 
 population density
 nonpoint source
 succession 
 fossil fuel 
 ecological footprint
 symbiosis 
 point source 
 competition 
 cost-benefit