Box 1.1 The role of biodiversity in mitigating the impacts of natural disasters

The year 2005 witnessed the largest financial losses ever recorded as a result of natural disasters, with preliminary estimates of total economic losses reaching over US$ 200 billion. Many experts have suggested that better management of natural ecosystems could lessen the loss of human lives and damage to property caused by such disasters, as explored in the four examples presented here, compiled from various sources.


Heavy rains in August 2002 and 2005 triggered catastrophic floods across Central Europe. Most of the natural, meandering stream and river systems in the region have been dyked, straightened and deepened over the past century, altering the flow of water accordingly. The natural ability of the land to retain and store water has also been reduced by the loss of once extensive marshlands and floodplain forests, and by the use of intensive farming methods. Large fields encourage runoff and erosion, and heavy machinery compacts the soil, limiting the land’s capacity to absorb excess water. Options for improved river basin management to reduce risks from fl oods are being explored.


In 2004, tropical storm Jeanne hit the island of Hispaniola, killing close to 3,000 people in Haiti, but only 18 people across the border in the Dominican Republic. This difference in human suffering has been linked to extensive deforestation in Haiti, where political turmoil and extreme poverty have led to the destruction of all but some 2% of the country’s original forest cover. Restoring forest ecosystems in Haiti would help to delay and reduce peak floodwater flows at local scales, making communities safe from the water torrents that now follow even normal rainfalls.


Mangrove forests have been rapidly disappearing from Southeast Asian coastlines in recent decades to make way for vast shrimp farms and tourist resorts. The tsunami that hit Asia in December 2004 revealed the devastating consequences of this loss. Although coastal vegetation could not have protected against catastrophic destruction in areas of maximum tsunami intensity, analysis of satellite images revealed that areas with mangrove or tree cover were significantly less likely to have experienced major damage. This underlines the protective role of coastal forests in reducing damage, including from regular storms, such as the typhoons that batter the Philippines every year. Efforts to replant mangroves are underway, but face challenges from coastal developers.


Hurricane Katrina touched down on a coastal region of the United States that has been under environmental pressure for over a century. Re-engineering of the Mississippi River, accomplished through a system of canals and levees, has diverted natural sedimentation flows and steadily eroded coastal wetlands; Louisiana alone loses more than 65 km2 of coastal wetlands every year. Development has also destroyed barrier islands and oyster reefs that buffered the coast. During the hurricane, the tidal surge was able to travel unimpeded up shipping canals and burst over the levees surrounding New Orleans. Although damage from the storm would have been considerable in any case, breaches occurred more often in areas where wetlands had been destroyed and levees were exposed to wave action.

Source & © CBD  Global Biodiversity Outlook 2 (2006),
Chapter 1:The Essential role of Biodiversity, p.16

Related publication:
Biodiversity (CBD) homeBiodiversity A Global Outlook
Other Figures & Tables on this publication:

Table 3.1 Strategic Plan scorecard

Table 4.1 Prospects for achieving the targets of the framework for assessing progress towards the 2010 Biodiversity Target

Table 2.1 Headline indicators for assessing progress towards the 2010 Biodiversity Target †

Figure 1.1 Biodiversity, ecosystem functioning, ecosystem services, and drivers of change

Figure 2.2 Locations reported by various studies as undergoing high rates of change in forest cover in the past few decades

Figure 2.8 Degree of protection of terrestrial ecoregions and large marine ecosystems (all IUCN Protected Areas Management Categories combined)

Figure 2.9 Frequency distribution of terrestrial ecoregions by percentage surface area under protection

Figure 2.11 Change the Marine Trophic Index (early 1950s to the present)

Figure 2.12 Impact classification based on river channel fragmentation and water flow regulation by dams on 292 of the world’s large river systems

Figure 2.13 Estimates of forest fragmentation due to anthropogenic causes

Figure 2.14 Status and trends in biological oxygen demand (BOD) of major rivers in five regions (1980-2005)

Figure 2.16 Estimated total reactive nitrogen deposition from the atmosphere (wet and dry) (early 1990s)

Figure 2.17 Number of alien species recorded in the Nordic terrestrial, freshwater and marine environment

Figure 2.19 Intensity of ecological footprint

Figure 4.1 Main direct drivers of change in biodiversity and ecosystems

Box 3.3 Principles, guidelines and other tools developed under the Convention

Box 1.1 The role of biodiversity in mitigating the impacts of natural disasters

Box 1.2 Contribution of ecosystem goods and services to national economies

Box 1.3 Millennium Development Goals

Box 2.1 Headline indicators for assessing progress towards the 2010 Biodiversity Target

Box 3.1 The Ecosystem Approach

Box 3.2 Programmes of work of the Convention

Box 3.4 The biodiversity-related conventions

Box 3.5 The business case for biodiversity

Box 4.1Summary of the main findings on biodiversity of the Millennium Ecosystem Assessment

Box 4.2 Policy options for the 2010 Biodiversity Target and beyond

Box 4.3 Elements of a strategy to reduce biodiversity loss

Box 5.1 Checklist of key actions for 2010

Figure 1.2 Economic benefits under alternative management practices

Figure 2.1 Annual net change in forest area by region (1990–2005)

Figure 2.3 Change in live coral cover across the Caribbean basin (1977-2002)

Figure 2.4 The Living Planet Index: trends in populations of terrestrial, freshwater, and marine species worldwide

Figure 2.5 Trends in European common birds in farmland and forest habitats

Figure 2.6 Red List Index for birds in marine, freshwater and terrestrial ecosystems, and in forest and shrubland/grassland habitats (1988-2004)

Figure 2.7 Trends in terrestrial surface under protected areas

Figure 2.10 Trends in mean trophic levels of fisheries landings (1950-2000)

Figure 2.15 Global trends in the creation of reactive nitrogen on Earth by human activity

Figure 2.18 Global Ecological Footprint

Figure 2.20 Aid activities targeting CBD objectives from 16 developed countries (1998-2003)

Figure 3.1 Participation in Convention processes

Figure 4.2 Links between food, energy and biodiversity loss

Figure 4.4 Outcomes for hunger reduction and biodiversity loss under the Millennium Ecosystem Assessment scenarios.