This week, weather experts at the United Nations announced that carbon dioxide concentrations are higher than ever . The report calls on world leaders to clamp down on greenhouse gas emissions at the UN climate talks taking place next month in Paris. However, government leaders aren’t the only people who can help save the world. In fact, some of the craziest schemes to halt, slow or even reverse global warming have come from other sources. Some are incredibly affordable and others require backing from investors. Some promise to be wildly successful, while a few have already stumbled. Read on to learn about some of the wildest ideas we’ve heard for fighting climate change .Slideshow-340870
