New technologies designed to capture carbon dioxide from the atmosphere are touted as solutions for protecting human and environmental health by greatly reducing harmful greenhouse gases that are a significant cause of global warming. But there’s debate about whether the techniques are truly capable of alleviating the threat. Fulton Schools Professor Klaus Lackner is among engineers and scientists who have pioneered carbon capture technologies and systems and touted their potential effectiveness. His carbon absorbing “mechanical tree” has attracted keen interest. But some environmentalists question whether Lackner and other developers of these systems can overcome the corporate, economic and political factors that may present roadblocks to their efforts.