What’s the single biggest way you can make an impact on global climate change? “Talk to your friends and family, and make sure your representatives are making good decisions,” Haq says. By voicing your concerns—via social media or, better yet, directly to your elected officials—you send a message that you care about the warming world. Encourage Congress to enact new laws that limit carbon emissions and require polluters to pay for the emissions they produce. “The main reason elected officials do anything difficult is because their constituents make them,” Haq says. You can help protect public lands, stop offshore drilling,