As the world continues to feel the effects of drought, sea level rise, and more volatile weather, it’s clear that adaptation efforts have never been more imperative. These initiatives are critically important in order to protect communities—especially in impoverished places—from the worsening impacts of climate change.WRI’s Vulnerability & Adaptation team has been working to ensure that adaptation is a central component of the international development agenda. Over the past few years, WRI and its partners have conducted practical research and analysis on three continents across a broad spectrum of adaptation topics, including monitoring and evaluation; case studies on information use for adaptation; the role of national institutions; and a broad set of decision-making principles for a changing climate. But what have we learned from the results of these efforts? And how can we ensure that global adaptation efforts are conducted effectively and efficiently?We recently stepped back and evaluated the work we’ve done to try and answer these questions. One of our clearest conclusions is that much remains to be learned about “what works” in adaptation. The results of our efforts point toward five areas of long-term, practical, applied research that could help provide a foundation for effective adaptation moving forward: adaptation success, critical thresholds, adaptation options, information systems, and institutions. Questions for Adaptation ResearchHere we introduce a set of research questions for each of these themes, along with a discussion of specific policy goals that would benefit from researchers’ tackling these questions:1) Adaptation Success: How will we know when adaptation efforts are succeeding? How does near-term success support or undermine long-term success?Why this question? There’s growing consensus that adaptation entails several categories of activities, each with different timeframes. Some activities reduce vulnerability to today’s climate variability; others require investment today that will bring future benefits. In 2007, WRI and the International Institute for Sustainable Development articulated a set of such categories along the “adaptation-development continuum.” Research needs to identify success indicators and success factors for these different adaptation categories. We also need research that shows when reducing vulnerability in the near-term can support longer-term adaptation and development success–and when short-term success might backfire in the long run. Unless we can learn to differentiate these cases, it will be difficult to develop effective adaptation monitoring & evaluation systems or allocate today’s resources in a way that has long-term impact.2) Critical Thresholds: What are the significant climate-related social and ecological thresholds that adaptation efforts can help society avoid? Can we identify leading indicators that warn us when we’re approaching such thresholds?Why this question? Since we don’t know exactly what climate change will bring, adaptation requires us to build flexibility into development planning. Understanding thresholds is a key part of this flexibility – we need to know if we’re reaching a point of no return where present activities make future vulnerabilities inevitable. Research today into critical thresholds will enable us to track the right variables and keep us from taking a wrong turn.3) Adaptation Options: Are standard sets of adaptation options emerging that can be applied to a variety of places with common environmental contexts (e.g., drylands, coastal zones, urban areas, mountain areas) or economic sectors (e.g., agriculture, water services, transportation, tourism)?Why this question? Many decision-makers seek the efficiency of a standard “menu” of adaptation options that are relevant to their location or sector, rather than generating a place-specific set of options from scratch. We need research that evaluates adaptation options across locations to explore whether such a menu is possible – and if so, what tools and criteria can help stakeholders tailor it to a specific location.4) Information Systems: What information can best support effective decision-making in the face of climate uncertainty? Which decision makers really need new information, and how should it be packaged so that they can use it effectively?Why this question? A great deal of adaptation investment to date has focused on producing information (often about vulnerability and impacts) that has not had a great deal of uptake into decisions and actions. WRI’s experience suggests that one reason could be due to an emphasis on “supply-driven” information products that are straightforward for climate scientists to produce, but are made without much reference to real patterns of how evidence is used in decision-making. Research that helps to really understand the needs, capacities, and incentives of specific “user groups” (e.g., village leaders, agricultural extension agents, urban planners) would help shift toward more action-oriented information products.5) Institutions: Which institutions help communities build resilience at the local level? What enabling conditions at national and global levels help these institutions thrive?Why this question? We are likely to see continued investments at the national level to develop adaptation policies, funding structures, coordination bodies, resource rights, and other aspects of an “enabling environment” for adaptation. These investments must be grounded in evidence from similar past investments in enabling conditions, both for adaptation and for other aspects of development. In particular, research needs to explore how national investments play out in practice for vulnerable people at the local level.Of course, the specific research agenda for each of these questions will vary by ecological context (e.g., drylands, mountains, urban areas) and by economic sector (e.g., agriculture, transportation, water management). Different questions may also rise to the top in different places depending on a country’s governance structure and political economy.These are some of the questions we need to address in order to make sure adaptation activities are carried out effectively. Now the real work begins—figuring out how to answer these questions.This is the first in a two-part series reflecting on WRI’s climate vulnerability and adaptation work. Stay tuned for Part 2, which will focus on the action agenda.