ABSTRACT
The human race is conducting an enormous, uncontrolled, and dangerous experiment. Our propensity for burning coal, oil, and gas for energy has fundamentally altered the distribution of carbon between the Earth and the atmosphere, shifting the energy balance of the Earth’s system, and intensifying climate extremes, affecting human and natural systems in virtually every part of the world. These changes are already stretching the capacity of many species and human populations to adapt. Over the next few decades, the world will inevitably experience worsening impacts on our health, livelihoods, ecosystems, economy, and security. In the longer term, our future is still in our hands, although the window of opportunity is shrinking. Concerted global action this decade to reduce greenhouse gas emissions rapidly and deeply, and innovative adaptation measures, are critical for ensuring the safety of future generations.
