A new government report says climate change and extreme weather already are causing disruptions in the U.S. energy supply that are likely to get worse as more intense storms, higher temperatures and more frequent droughts occur.

The report, released Thursday by the Energy Department, says blackouts and other problems caused by hurricanes, such as Superstorm Sandy, and other extreme weather are likely to be repeated across the country as an aging energy infrastructure struggles to adapt to rising seas, higher storm surges and increased flooding. A range of energy sources are at risk, from coal-fired power plants to oil wells, hydroelectric dams and nuclear power plants.

Climate-related disasters have already cost billions of dollars. The report says costs could grow exponentially unless a more comprehensive and accelerated response is adopted.