The United Nations stated that investing in energy efficiency for power plants, buildings, and cars is the most effective way to combat global warming, with costs estimated to be in the hundreds of billions of dollars. The report, presented at a meeting in Vienna with 1,000 delegates from 158 nations, also pointed out that curbing greenhouse gas emissions could be more cost-effective in developing countries compared to wealthier nations. The report suggested that to reduce emissions to current levels by 2030, it would require 0.3 to 0.5 percent of projected GDP or 1.1 to 1.7 percent of global investment flows. Yvo de Boer, the head of the U.N. Climate Change Secretariat, highlighted that energy efficiency is the most promising solution for reducing greenhouse gases in the near future. The 216-page report was recently released online. According to him, the findings of the study could provide valuable guidance for governments convening in Austria to discuss long-term strategies for combating global warming beyond the UN's Kyoto Protocol. The protocol requires 35 wealthy nations to limit greenhouse gas emissions by 2008-12. The report suggests that investments and financial flows totaling $200 billion-$210 billion will be needed by 2030 to reduce greenhouse gas emissions to current levels, including initiatives related to energy supply, forestry, and transportation. Improving energy efficiency in power plants, increasing fuel efficiency in vehicles, and enhancing insulation in buildings are among the recommended measures. The study predicts a transition to renewable energy sources like solar, hydropower, and some nuclear power. It also anticipates that investments in helping countries adapt to the effects of climate change will amount to billions of dollars in 2030, which includes addressing diseases like malaria and constructing protective structures like dykes. The report suggests that carbon markets will need to be expanded significantly in order to meet the growing demand for investments and financial resources. Currently, companies are responsible for around 60 percent of global investments. Experts noted that this report is the first of its kind to provide an overview of the necessary investments for a single year, specifically 2030. The report addresses some missing information in a broader context provided by previous reports, like one from former World Bank chief economist Nicholas Stern, who stated that it would be more cost-effective to address climate change now rather than later. U.N. reports this year have also predicted that global warming will lead to more heat waves, droughts, diseases, disruptions in agriculture, and rising sea levels worldwide. De Boer emphasized the need for increased investments in developing nations, stating that the majority of cost-effective opportunities are in these countries. He also mentioned that this does not mean wealthy nations should only invest abroad and not domestically, as over half of the required energy investment is needed in developing countries. China is constructing two new coal-fired power plants every week to support its expanding economy. The implementation of cleaner technology, such as removing and storing carbon emissions, could be beneficial in addressing this issue.