Adapting to Climate Variability and Change

Climate change is no longer a debate; it is now a widely accepted fact. The unprecedented global attention in 2007 to the United Nations Climate Change Conference (Bali, December) and to the Fourth Assessment Report of the WMO/UNEP Intergovernmental Panel on Climate Change (IPCC) is testimony to the high priority given to climate across all regions and socio-economic sectors. Mounting evidence indicates that the impacts of climate change are already happening and will worsen in the future, making adaptation a vital societal need.

The United Nations Framework Convention on Climate Change has adopted a number of activities to deal with adaptation, including the five-year Nairobi work programme on impacts, vulnerability and adaptation to climate change. The aim is to help all countries improve their understanding of the impacts of climate change and to make informed decisions on practical adaptation actions and measures. The Bali action plan identified the need for enhanced action on adaptation by Parties to the Convention. WMO, in keeping with its role as the UN system’s authoritative voice on weather, climate and water, has been playing a key role in these initiatives. “Adapting to climate variability and change” has been chosen to be the theme for this issue of the Bulletin.

The IPCC Working Group on Impacts, Adaptation and Vulnerability addressed three main issues in the Fourth Assessment Report: impacts of climate change which are observable now; future effects on different sectors and regions; and responses to such effects. The Working Group leaders identify 12 key messages, which are summarized in their article. Impacts of climate change are occurring now; adaptation will be necessary to address those arising from past emissions. It is essential to develop a portfolio of strategies that includes adaptation, mitigation, technological development and research (climate science, impacts, adaptation and mitigation).

Suitable adaptation strategies hinge upon the availability of climate information at regional to country and even local scales. Coupled atmosphere-ocean general circulation models are the primary tools available today to simulate and project climate change. While their skills on the global and continental scales are rapidly increasing, their spatial resolutions are still too coarse to provide fine-scale climate-change information required for most impact assessments. Regionalization tools have been increasingly applied to a wide range of climate-change problems. In applying them, however, it is necessary to fully comprehend the key assumptions underlying their use, as well as their potential and limitations.

In the IPCC Fourth Assessment Report, the Working Group on the Scientific Basis termed the warming of the climate system as “unequivocal”, with most of the recent warming “very likely to be human-induced”. If we follow the assessment reports since the beginning of the process in 1990, we can see the remarkable progress in the clarity of our under­standing, driven largely by the rapid advances in climate science. Large uncertainties and gaps in our knowledge of climate change remain, particularly on adaptation-relevant regional and local scales. Concerted efforts must be made to address these gaps by sustaining and improving monitoring, prediction, data access, communication, capacity-building, research and other aspects of climate science.

Over the last 10 years, an innovative process known as the Regional Climate Outlook Forum (RCOF) has been undertaken by WMO, National Meteorological and Hydrological Services (NMHSs), regional climate institutions and other international organizations, to provide consensus-based early warning seasonal climate information for reducing climate-related risks and supporting sustainable development efforts of spe­cific regions. RCOFs bring together cli­mate scientists, policy-makers and the general user community to develop warnings of potential impacts of the climate on various socio-economic sectors. With their demonstrated capability of providing regionally consistent and user-targeted climate information, RCOFs are uniquely placed to contribute to decision-making at regional, national and sector levels.

The assessment and monitoring of climate changes are based on decades and centuries of atmospheric and oceanic observations across the world. These observations, coupled with palaeoclimatic reconstructions, led the IPCC to conclude that the average northern hemisphere temperatures during the second half of the 20th century were likely higher than any other 50-year period in at least the past 1 300 years. WMO stimulates and coordinates climate-monitoring activities around the world and helps capacity building in developing countries and Least Developed Countries. The priorities are applications of satellite, marine and other in situ data, improvement in monitoring climate extremes, better use of phenological data, and capacity-building. The annual WMO state of the climate reports highlight the benefits of WMO Members working together to monitor, and improve the scientific understanding of, the global climate.

Agrometeorological services strive to improve and protect agricultural production, which is crucial for food security worldwide, as well as for the livelihood of farmers. It is important to incorporate local knowledge, relevant science and appropriate policies into agrometeorological services, whatever climate conditions and changes the farmers are subject to. “Response farming” is a method of identifying seasonal rainfall variability and its predictability, along with the related risks, and addressing these risks at the farm level. This means adapting cropping to the ongoing rainy season by guidance of agronomic practices; using past experiences, including meteorological interpretations; and traditional knowledge. Climate change brings complications to organized response farming but a differentiation of farmer and farming system is the real issue for agrometeorological services in a changing climate.

Disasters as a result of weather, climate and water extremes account for the majority of all natural disasters. One of the most threatening aspects of global climate change is the likelihood that extreme weather and climate events will become more variable, more intense and more frequent. The IPCC has concluded that increases in extremes, as well as changing socio-economic and demographic trends, have contributed to rising vulnerabilities. NMHSs are well-placed to reduce disaster losses under current and changing climate conditions, through risk as well as crisis management. The associated actions include: provision of hazard information for planning, prediction products for impending risks, monitoring to detect hazards and emerging threats, early warnings for emergency response and recovery operations, and education and capacity building.