针对一篇英文文章，将每个段落的主题进行总结并生成简洁的摘要。
"In recent years, the use of renewable energy has increased significantly worldwide. Solar and wind power are the most popular sources of renewable energy, with hydropower and geothermal energy also playing a role. However, there are still challenges in the widespread adoption of renewable energy, such as the high initial cost of installation and the need for energy storage solutions. In addition, fossil fuels continue to dominate the global energy mix, with coal being the most widely used. If we want to make a significant impact on reducing carbon emissions, there needs to be policy support and investment in renewable energy."
Renewable energy has become increasingly popular worldwide, with solar and wind power being the most widely used. Hydropower and geothermal energy are also used to generate electricity. However, challenges remain, such as the high installation cost and the need for energy storage solutions. Although fossil fuels, especially coal, still dominate the global energy mix, investing in and supporting policy for renewables can have a significant impact on reducing carbon emissions.