Change in the Earth's climate and its adverse effects have always been a common concern of humankind. The current challenge of climate change is typically formulated as:

• • The Earth's climate is warming.

• • A warming climate is dangerous.

• • We are causing the warming by emitting carbon dioxide (CO2) from burning fossil fuels.

• • We need to prevent dangerous climate change by rapidly reducing and then eliminating our CO2 emissions.

In spite of the perceived urgency of the problem and international climate treaties and agreements that were first signed in 1992, global CO2 emissions continue to increase while targets and deadlines continue to be missed.

Most people feel that climate change is a very serious issue. Depending on your perspective and values, there will be much future loss and damage from either climate change itself, or from the policies designed to prevent climate change. Conflicts surrounding climate change have been exacerbated by oversimplifying both the problem and its solutions.

Acknowledging disagreement is not the same as rejecting climate change as an important problem. In the context of the international treaties and agreements on climate change, both the problem of climate change and its solutions are framed as a global issue. This framing of the central challenge that focuses on reducing global carbon emissions has allowed technical fixes such as geo-engineering and low-carbon energy to take center-stage. This focus has come at the expense of a host of wider visions for social, economic, and political change, particularly at the national and local levels.

Part One describes how the challenge of climate change has evolved in the context of a complex interplay among scientists, the organizations that support research, government-sponsored assessments of climate research, national and international climate policy, politics, and the needs and desires of peoples and nations in a rapidly changing world. Polarization has deepened in a fog of confusion about what we know versus what we do not know and what we cannot know. A populace that is trying to understand climate change is left confused by international and national policies and commitments that do not seem doable or politically feasible.