Planetary system evolution and the extended biosphere: we humans are products of Earth's biosphere; we have become its co-creators; can we be its regulators?

The energy balance of a planet is set by the sunlight entering and the heat radiating back from it. Earth's biosphere adds new complexity as energy flows through global marine and terrestrial ecosystems altering physical and chemical systems, including global climate. Energy is essential for life, and the main constraint on abundance and productivity is the amount of energy an organism can harvest. When the first lifeforms evolved fire-making culture-there is evidence in our hominin ancestors, some 1 million years ago-it sparked a novel form of energy relationship: deliberate combustion, which would change the planet. The innate drive to harvest ever more energy changed the evolution of our species and transformed the world's environments. Humans became the dominant species globally. As humans have become ever more successful and ingenious at harnessing energy, our scope grows extraterrestrial: there are plans to colonize the Moon and Mars. Human activity has extended the reach and influence of Earth's biosphere to other worlds light-years away. Meanwhile, the impact of humanity's burning of ancient fossil life has altered the energy balance of this entire planet. In recent decades, humanity's influence on the biosphere is shifting Earth systems, altering the biology, chemistry and physics of the planet. The destabilizing impact of humanity's energy exploits on Earth's unique biosphere risks the survival of multiple ecosystems, and the future of our own species. The biosphere is evolving towards a new state of equilibrium some centuries hence. Yet, even as this momentous shift occurs, humanity is on the cusp of self-regulating: changing energy source, altering certain planetary activities and perhaps geoengineering the climate. A new biosphere equilibrium could be reached sooner than expected.This article is part of the discussion meeting issue 'Chance and purpose in the evolution of biospheres'.