Carbon plays an unparalleled role in our lives: as the element of life, as the basis of most of society’s energy, as the backbone of most new materials, and as the central focus in efforts to understand Earth’s variable and uncertain climate. Yet in spite of carbon’s importance, scientists remain largely ignorant of the physical, chemical, and biological behavior of many of Earth’s carbon-bearing systems. The Deep Carbon Observatory is a global research program to transform our understanding of carbon in Earth. At its heart, DCO is a community of scientists, from biologists to physicists, geoscientists to chemists, and many others whose work crosses these disciplinary lines, forging a new, integrative field of deep carbon science.
DCO science is roughly divided into four Communities, each with unique roles to play over the course of the next few years. The Extreme Physics and Chemistry Community is concerned primarily with the most fundamental questions regarding how carbon interacts with other elements under the high temperature and pressure conditions of deep Earth. Scientists in the Reservoirs and Fluxes Community are asking how much carbon cycles into and out of Earth, for example during volcanic events, and analyzing diamonds and other carbon-containing minerals to document how much carbon is stored deep underground. The Deep Energy Community focuses on the many ways carbon compounds (such as hydrocarbons) are created, stored, and interact with Earth’s deep interior, and how organic molecules may have provided the raw materials for early life. And the Deep Life Community is on a quest to document the extreme limits and global extent of subsurface life in our planet.
So what have these Deep Life researchers discovered? DCO researchers have found microbial communities deep underground that have similar populations in places as far-flung as South Africa and Finland. Deep viruses in the crust and subsea sediment may be vital to the genetic diversity of microbial life. Some deep microbes have extraordinarily low rates of respiration, possibly resulting in “microbial zombies” that may not divide cells for millions of years. One particularly big surprise was the discovery of deep fungi—organisms with complex cell structures.