Scientists say expanding the world’s conservation areas to help protect animals and plant life is unlikely to be effective on its own. The reason: rising levels of human activity in and around protected natural areas. Cambridge University researchers studied thousands of conservation areas in more than 150 countries. They found that, in general, recognizing spaces as protected is not reducing human activity in at-risk areas. The researchers found that a lack of money to pay for land protection is affecting conservation efforts. So is a lack of interaction between people who live in protected natural areas and outsiders.