 Earth is a living system that cycles many elements necessary for life, and car oceanographer Matt Long tells us more. So we're here at the National Center for Atmospheric Research with NCAR scientist Matt Long, and can you tell me a little bit about what you do here at NCAR? My work tends to focus on the application of Earth system models. And the primary thing that I do is work on the development of the community Earth system model. And specifically I focus on the component of that model that represents the role of the ocean in the global carbon cycle. How did you get involved in this type of research, and how does that relate to the work that you're doing now? So I actually started my career as a civil environmental engineer, designing water and wastewater treatment plants. And then over time I got interested in larger and larger scales and thinking about the climate problem. Climate change is really a manifestation of a human environmental interaction that's gone awry. We've been using the atmosphere as kind of a dumping ground for CO2. And what we need to do now is develop the tools and skills to really manage that problem. Do you only use computer models for your investigation? In addition to using Earth system models, we also depend heavily on observation. The work that I've primarily focused on at NCAR entails observations collected from a Gulfstream 5 aircraft platform. And in particular we've done things like fly sorties over the Southern Ocean to measure the distribution of oxygen and CO2. And so it's that interchange between extracting information out of observations of the real system and comparing them with the model that we really advance the science. Why is it important to study the Earth as a system? Yeah, so that's a really interesting question. And I think the answer is best found by considering the history of this planet. Life evolved about three and a half billion years ago. But when life first evolved, there was no oxygen in the atmosphere. But about 2.2 billion years ago, some microorganisms developed this neat trick called photosynthesis. They could harvest energy from the sun and as a byproduct of that they produced oxygen. And that opened up a niche for organisms like humans to exist. And so the point there is that the natural biosphere persists in a delicate balance and has played a fundamental role actually in controlling the nature of the planet. And so the challenge then is for us to really understand the delicate nature of the interconnected networks that sustain the biosphere and sustain a habitable planet and enable our societies then to dovetail with those natural networks.