Climate change will affect many sectors, including agriculture, electricity production, transportation, forest and land use, and water management. Climate change is not just an environmental problem; its impacts affect all departments of government. This underscores the need for a comprehensive response by government and for different approaches to decision making that respond to the unique nature of the climate challenge.This publication explores five key elements—public engagement, decision-relevant information, institutional design, tools for planning and policymaking, and resources—that we believe will significantly strengthen the ability of national governments to make effective adaptation decisions. Our arguments for why decision makers should focus on these elements are based upon the results of a wide-ranging and interactive research program (see Methods Box on page 20). Over 100 adaptation experts, public officials, sector-based practitioners and civil society representatives, from more than 30 countries, contributed to our research effort.