What is the fine-grained topic of the following text: The ash cloud, by reminding us of the risks of not being able to fly planes, is a timely reminder that the risks of global warming must be weighed against the risks of high energy costs - the risks of poverty (cheap energy creates jobs), of hunger (fertiliser costs depend on energy costs), of rainforest destruction and indoor air pollution (expensive electricity makes firewood seem cheaper), of orangutan extinction in subsidised biofuel palm oil plantations. Only return the topic.
Weighing risks of global warming against high energy costs.