Houston is recognized worldwide for its energy industry, particularly for oil and natural gas, as well as for biomedical research and aeronautics. Renewable energy sources, wind and solar, are also growing economic bases in Houston. The ship channel is also a large part of Houston’s economic base. Because of these strengths, Houston is designated as a global city by the Globalization and World Cities Study Group and Network. The Houston area is the top U.S. market for exports, surpassing New York City, according to data released by the U.S. Department of Commerce’s International Trade Administration. Petroleum products, chemicals, and oil and gas extraction equipment accounted for approximately two-thirds of the metropolitan area’s exports last year. The top three destinations for exports were Mexico, Canada, and Brazil.