Water touches practically all aspects of our lives. Water is the life blood of our planet -- providing the life line to people, communities, biodiversity and in fact our economy as a whole and climate change threatens those very same things and to a large extent through impacts on water.
The IPCC's Fourth Assessment Report clearly indicated the climate change impacts on water. The Report lists 32 examples of major projected impacts of climate change. Of these: 25 include primary links to hydrological changes; of the other seven, water is implicated in four.
The IPCC technical report (2008) underpinning the 4th assessment report concluded unambiguously, inter alia, that: "the relationship between climate change and freshwater resources is of primary concern and interest". So far, "water resource issues have not been adequately addressed in climate change analyses and climate policy formulations"; and, according to many experts, "water and its availability and quality will be the main pressures, and issues, on societies and the environment under climate change".
It is for this reason that water colleagues in the UN System, represented through UN-Water, have chosen climate change as a key Thematic Priority Area for UN-Water to address through its more than 50 member agencies and partner organizations.
It is also for this reason that we are very pleased that CONAGUA took the lead on this important issue here in Cancun to organize the Dialogue for Water and Climate Change.
It is often said, mitigation is about energy and adaptation is about water. But what does this mean in practical terms? The synthesis of the Dialogue for Water and Climate Change that took place this week made several points. Many of which are relevant to UN agencies in their work to assist countries to adapt. But as time is short, let me focus on the one point closest to my work, that of natural infrastructure.
Services provided by natural infrastructure
Water-related ecosystems are critical to the delivery of ecosystem services from the world's natural capital. Examples include the regulation of water quality, flood regulation, provisioning of water for agriculture, industry and communities, recreation, energy and others. All of which are under threat in a changing climate.
In fact, the Millennium Ecosystem Assessment clearly pointed out that the majority – that being over 65% -- of our ecosystem services, such as these just mentioned, are in decline, with climate change being one of the most important drivers.

Given the vast number of services our water-related ecosystems provide, it is critical that we manage and restore them through integrated approaches as was called for almost 20 years ago in Rio. It is through the application of integrated approaches that we will be able to restore and maintain resilience in our ecosystems, such that they can continue to provide these services. And through these same integrated approaches, we will be able to adapt to climate change.
Integrated Management and Ecosystem-based Adaptation
We have invested, and continue to invest, large amounts of money in water-resources infrastructure. But drinking water, flood control, water supply for irrigation, and water for recreation cannot rely solely on hard infrastructure. Considering the ecosystem services that water-related ecosystems can provide, using them wisely through maintaining natural infrastructure – or ecosystem functionality and resilience -- can be a cost-effective alternative to hard infrastructure development.
So not only does climate change impact most on water resources, it is through the maintenance and use of those very same water resources that we can adapt.
So we need to take integrated water resources management just one step further by adequately considering climate information and data to implement "adaptive water resources management" or ecosystem-based adaptation (EBA).
Contacts:
Tim Kasten
Tim.Kasten@unep.org