From the new National Academy of Sciences report on climate modeling:
Global warming is a pivotal environmental and social issue of the 21st century. Its long time scales, diverse consequences, and direct ties to our global energyproduction infrastructure make it challenging for societies around the world to grapple with and threaten humanity’s ability to mount an effective response. This challenge is compounded by the complexity of the Earth-human system. The fundamental science of greenhouse gas-induced climate change is simple and compelling. However, genuine and important uncertainties remain (e.g., the response of clouds,
ecosystems, and the polar regions) and need to be considered in developing scientifically based strategies for societal response to climate change.