Background Paragraph: Because of human activities, there is more carbon dioxide in the atmosphere today than in the past hundreds of thousands of years. Burning fossil fuels and has released great quantities of carbon dioxide into the atmosphere. Cutting forests and clearing land has also increased carbon dioxide into the atmosphere because these activities reduce the number of autotrophic organisms that use up carbon dioxide in photosynthesis. In addition, clearing often involves burning, which releases carbon dioxide that was previously stored in autotrophs. 
Story: Two cities had different energy source. Big city burned fossil fuels cut forests and cleared land, while Blue city used alternative sources of energy.
Which city cleared fewer lands? Which city cleared more lands? Which city contributed less to global warming? Which city contributed more to global warming? Which city cut fewer forests? Which city cut more forests? Which city destroyed fewer autotrophic organisms? Which city destroyed more autotrophic organisms?