The green tide seems to be turning in 2011 for the Top 200 Environmental Firms, with overall revenue for list participants rebounding 6.2% to $51.3 billion from last year's recession-driven falloff. In international work, there were strong gains fueled by the needs of growing economies and environmental requirements of natural-resource development projects. Top 200 firms also climbed in the rankings by acquisition, which added significant girth to some list participants.
Based on revenue reported in 2010, there was growth in nearly all the markets. Even with stalled projects and strapped public-sector owners, domestic revenue grew 4.3% to $41.3 billion.