## Section 2 Loss of Biodiversity Accelerating

### 1. The State of Loss of Biodiversity in the World

The Millennium Ecosystem Assessment, which was conducted by the United Nations from 2001 through 2005 and in which 1,360 experts from 95 countries participated, pointed out that over the past fifty years humans have changed ecosystems at a speed and on a scale that the world has never seen before, and as a result have caused qualitative and overall irreversible damage in terms of diversity of life. In addition, the Global Biodiversity Outlook 3 (GBO3) that was published by the Secretariat of the Convention on Biological Diversity in May 2010 predicted that extinction of species is proceeding at a speed much faster than in any other time in history, and that habitats will be lost and there will be changes in distribution and abundance of species.

For example, the extinction of species in the 21st century is predicted to be proceeding at a rate that far surpasses the extinction rate estimated based on fossil records and the Red List, due to disappearance of habitats resulting from climate change and changes in land use (Figure 3-2-1: Speed of Extinction Rates and 21st Century Projections Scenario). There is also a Red List Index, which is an indicator that shows the state of risks of extinction for each taxonomical group. A value of 1 indicates that all of the species in that taxonomical group are not heading toward a crisis of extinction in the near future, and a value of 0 indicates that all of the species in that taxonomical group are already extinct. Shifts in this index show that there is a danger of extinction for birds compared with the ideal situation, although the danger of extinction for birds is lower than other taxonomical groups, and that the danger of extinction for amphibians is much higher than other taxonomical groups. It can also be seen that since around the middle of the 1990s the possibility of extinction of coral has increased rapidly (Figure 3-2-2: Shifts in the Red List Index).

As an example of the state of specific ecosystem changes, here we will take a look at forests, which are representative natural environments on land. According to the Millennium Ecosystem Assessment, over the last 30 years half of the world's forest land area has been lost, and forests have decreased to the point that they now occupy approximately 31% of the Earth's surface. Trends in recent years also show that forests are continuing to decrease. In the 1990s approximately $ 160,000 km^{2} $ of forests was converted to other uses or lost each year. Although the speed of that loss has slowed in comparison with the 1990s, during the period from 2000 to 2010 nearly $ 130,000 km^{2} $ of forests, which is comparable to the combined areas of Hokkaido, Shikoku, and Kyushu, has been converted to other uses or lost each year. In terms of regions, decline is noticeable in South America, Africa, South Asia, and Southeast Asia (Figure 3-2-3: By-Country Net Change in Global Forest Area (2000–2010)).

For example, the savannah region in central Brazil

Figure 3-2-1 Past Extinction Rates of Species and Scenario Projection for the 21st Century

Figure 3-2-2 Red List Index

Source: Secretariat of the CBDs "Global Biodiversity Outlook 3 (GBO3)"