This paper gives an historic perspective on 10 critical phases and actions in advancing an understanding of climate change and taking appropriate domestic and international action. Credit goes to atmospheric scientists for their committed efforts to understand, model and measure the impacts of climate change. Today, greenhouse gases are at a record level and little doubt remains that greenhouse gases (GHG) warm the atmosphere and that human-made climate change is real. Recognizing the urgency of responding to climate change, the 2013 US Climate Action Plan aims to cut carbon emissions and prepare to deal effectively with the economic, social, and environmental impacts of climate change. Many US states, Tribes, and local communities have also begun to take action to reduce GHG emissions and adapt to the impact of climate change, especially on disadvantaged communities. While recognition of the urgency of action on climate change is growing in government and in large parts of the business and financial sector, it has taken over 40 years to get to this point. While an understanding of the reality and impact of climate change has grown, significant efforts to reduce the concentration of greenhouse gases in the atmosphere and stabilize global warming have not occurred. The problem that society faces is not the absence of scientific knowledge, but rather the need to reduce GHG emissions and create resilient and adaptive responses to climate change. This paper concludes that future successes will need more effective collaboration between government, business, and society to address climate change and greater public understanding of the impacts of climate change on human health and economic well-being.