Fuel oil pollution control and additional maintenance required after burning it often outweigh the low cost of the fuel. Burning fuel oil, particularly residual fuel oil, produces uniformly higher carbon dioxide emissions than natural gas. Heavy fuel oils continue to be used in the boiler "lighting up" facility in many coal-fired power plants. This use is approximately analogous to using kindling to start a fire. Without performing this act it is difficult to begin the large-scale combustion process. The chief drawback to residual fuel oil is its high initial viscosity, particularly in the case of No. 6 oil, which requires a correctly
The Private Life of Plants it makes use of almost no computer animation. The series also discusses fungi, although as it is pointed out, these do not belong to the kingdom of plants. The mechanisms of evolution are taught transparently by showing the advantages of various types of plant behaviour in action. The adaptations are often complex, as it becomes clear that the environment to which plants must adapt comprises not just soil, water and weather, but also other plants, fungi, insects and other animals, and even humans. The series shows that co-operative strategies are often much more effective than predatory ones, as these often