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Interview with Tim Kasten: Climate Change and Water

December 2010


Vice-Chair Tim Kasten, represented UN-Water at the recent Dialogues for Water and Climate Change (D4WCC) held at the 16th Conference of the Parties of the United Nations Framework Convention on Climate Change (COP16).


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).

Ecosystem-based adaptation has had various meanings attached to it, though the Convention on Biological Diversity's 2nd Ad Hoc Technical Expert Group (AHTEG) on Biodiversity and Climate Change, defines EBA as the use of biodiversity and ecosystem services as part of an overall adaptation strategy. It involves the use of environmental or natural resource management to aid adaptation to climate change, improve the resilience of ecosystems, enhance ecosystem services and sustain peoples' livelihoods.

The aim of EBA is to facilitate climate change adaptation by both society and the environment working in synergy.

But just like hard infrastructure, natural infrastructure, in particular its restoration and sometimes even its maintenance, has its costs. Emerging science and data, such as the preliminary findings of the UNEP Green Economy Initiative, indicate that investment in the development of water resources designed to both ensure the maintenance of biodiversity and ecosystem services can be expected to pay long-term dividends. But for these green investments to take place there must be economic tools, such as ecosystems valuations and payments for ecosystem services that make good business sense.

REDD+ for Water?

As I also work on REDD+ (reducing emissions from deforestation and forest degradation) I have often been asked how we can do for water what we have done for forests. How can we value our water ecosystems the way we do our forested ecosystems such that the benefits of their restoration, protection and maintenance outweigh the costs?

We don't necessarily have to put a carbon value on freshwater ecosystems, but carbon sequestration is only one of many services provided by ecosystems. What about all the other services I mentioned already: flood prevention, water regulation and provisioning, recreation, etc. Are these services not also valuable to us? Absolutely they are.

Maintaining a healthy ecosystem is cheaper than restoration and the benefit/cost ratio higher -- though some evidence exists on not only the value of our freshwater ecosystems, but their benefit/cost ratio to restore those systems that are degraded. Let me give just one example from the study on The Economics of Ecosystems and Biodiversity (TEEB) on restoration of degraded systems.

TEEB found that the high end cost of inland wetland restoration is 33,000 USD/hectare. An average scenario for annual benefits is about 14,200 USD/hectare yet the net present value of benefits over 40 years is 171,300 USD/hectare. This is an internal rate of return of 12% with a benefit/cost ratio of 5 to 4. For lakes and rivers the same scenario gives us a rate of return of 27% and a benefit/cost ratio of 15 to 5.

Though much of this science is still emerging, it is of the type necessary to make a REDD type mechanism – or payment for ecosystem services mechanism -- work for water resources.

With the REDD+ mechanism moving forward, perhaps now is the time to develop a payment for water-related ecosystem services mechanism that will enable long-term, green, economic solutions to both the water and climate crises.

Last update:07 Oct 2014