Since the industrial revolution, atmospheric concentrations of greenhouse gases, especially carbon dioxide, have increased considerably as a result of fossil fuel use and deforestation. This has significantly raised the threat of rapid increases of global temperatures. As concern over this prospect has grown, various options have emerged for mitigating the problems and threats associated with climate change. Debates over the options for decreasing greenhouse gas emissions have been particularly intense, and have frequently been characterized by a lack of understanding by many of the parties involved.