By Ban Ki-Moon

Tomorrow is the International Day for Biological Diversity. Biodiversity is the foundation of life on earth and one of the pillars of sustainable development.

The richness and variety of life on earth make possible the ecosystem on which we depend: for clean water, food, shelter, medicine and clothing. Environments rich in biodiversity are resilient when stricken by natural disaster.

All this is of particular importance for the poorest citizens of our world. Those who live on only a few dollars a day need biodiversity to meet their basic needs. Without the conservation and sustainable use of biodiversity, we will not achieve the UN Millennium Development Goals.

However, biodiversity is being lost at an unprecedented rate. This, in turn, is seriously eroding the capacity of our planet to sustain life. It is for this reason that leaders attending the World Summit on Sustainable Development in Johannesburg in 2002 agreed to achieve a significant reduction in the rate of loss of biodiversity by 2010.

This commitment was reiterated at the 2005 World Summit. The 2010 biodiversity target is now fully integrated into the framework of the Millennium Development Goals. As a sign of further support, the international community decided to declare 2010 the International Year for Biological Diversity.

As the world focuses more attention on climate change, the links between climate change and biodiversity are being articulated. The Millennium Ecosystem Assessment, "a state-of-the-art appraisal of the world's ecosystems and the services they provide", has identified climate change as one of the biggest causes of our planet's loss of biodiversity, along with changing land use patterns.

In addition, the recently released report of the Intergovernmental Panel on Climate Change made it crystal clear that climate change is real and will continue to affect our lives and ecosystems for many years to come. The impacts will include the extinction of ever increasing numbers of species, further weakening a number of already fragile ecosystems.

It is therefore timely that the theme of this year's observance of the International Day for Biological Diversity is "Biodiversity and Climate Change".

Indeed, the conservation and sustainable use of biodiversity is an essential element of any strategy to adapt to climate change. For example, mangrove forests and other coastal wetlands represent a bulwark against extreme weather events and rising sea levels.

As agricultural landscapes become warmer and drier, the diversity of livestock and cereal crops can provide farmers with options to cope with new conditions. Forests, peat lands and other ecosystems contribute to sequestering carbon dioxide from the atmosphere, thereby helping to mitigate increases in greenhouse gas emissions.

Through the Convention on Biological Diversity and the United Nations Framework Convention on Climate Change, the international community is committed to conserving biodiversity and combating climate change. The global response to these challenges needs to move much more rapidly and with more determination at all levels - global, national and local.

For the sake of current and future generations, we must achieve the goals of these landmark instruments.

The author is Secretary-General of the United Nations.

(Xinhua News Agency May 21, 2007)