Depletion of biological diversity is taking place much faster than natural extinction. Human activity (land use, soil and water pollution and degradation, sea and ocean pollution, introduction of foreign species, etc.) is the main cause of this impoverishment, and climate change is exerting additional pressure which has already begun influencing animal and plant biodiversity.
According to the Intergovernmental Panel on Climate Change (IPCC), average temperatures at the earth’s surface are set to rise by between 1.4 and 5.8°C by the end of the 21st century, with more warming of land areas and higher latitudes than of oceans and tropical regions. Sea level will probably rise by between 0.09 and 0.88m. In general the forecast is for more precipitation in higher latitudes and equatorial regions and less in subtropical regions, with an increase in heavy precipitation. It is estimated that by 2080 around 20% of coastal wetlands could have disappeared as a result of higher sea level.
Even though modelling of biodiversity change is difficult, such change clearly has important implications for the human population, species distribution and ecosystems (changes in the breeding and growth seasons of animals and plants, species distribution, population densities, the frequency of parasite infestations and disease, etc.).
Among other things, the disturbances may accelerate species disappearance and create opportunities for new species to establish themselves. Many species already at risk will be under even greater threat of extinction. The fact is that changes in the majority of ecosystems are highly probable.
In addition, biodiversity alteration in ecosystems and landscapes as a result of climate change and other pressures (such as deforestation and forest fires) is liable in turn to influence world and regional climate, in particular by affecting absorption and emission of greenhouse gases.
Similarly changes in the structure of biological communities in the upper ocean layers could alter ocean absorption of CO2 and influence weather conditions and climate change.
The Assembly wishes to encourage measures to promote conservation of biological diversity and reduce the effects of climate change and climatic extremes on biodiversity.
We need to develop evaluation systems now so as to improve our knowledge of how biological diversity interacts with ecosystem structure and functioning and deepen our understanding of how biodiversity reacts to climate change factors and other exogenous pressures.
As part of overall strategy it is vital to consider measures and policies for conservation and sustainable use of biodiversity so that populations are less vulnerable to climatic extremes.
Synergy and interaction need to be encouraged between national, regional and local environmental projects and policies on climate change and the objectives of international treaties such as the Convention on Biological Diversity.