Current satellite observations of Earth's land carbon cycle are better than ever. However, it's still unclear how to combine all this information or develop consensus among sources. The United States Greenhouse Gas Center is working on a common approach to harmonize carbon data across sources and quantify its uncertainty. This work includes setting standards and developing common tools for data formatting, product delivery, and intercomparison. Our hope is that these capabilities will make it clear where models agree or disagree, how accurate they are, and how much uncertainty exists. This will help scientists, policymakers, and others to understand the strengths and limits of each product.