In June 1992, at the Rio Earth Summit,
the United Nations Framework Convention on Climate Change (UNFCCC)
was signed by 160 nations. The adoption of the Convention signals the recognition
that climate change represents a problem of universal importance.
The Earth's climate has been undergoing change for eons of time as the atmospheric and terrestrial conditions have changed. The average global temperature is influenced by many factors, including the intensity of the solar radiation, the type of ground cover, the amount of ocean area and cloud cover, and the gaseous composition of the atmosphere itself.
The Earth is warmed by incident solar radiation, and in turn, the Earth radiates energy back to outer space. In the absence of an atmosphere, the average equilibrium temperature of the Earth's surface would be approximately -18°C, an inhospitable environment for many existing life forms. The atmosphere acts as a greenhouse and traps some of the energy that would otherwise be radiated to space. The result of this greenhouse effect is a warmer Earth, and the average temperature is currently approximately 15°C.
The earth is presently in a general warming phase, and in fact, scientific observations over more than a century indicate that average annual temperatures have been climbing at unusually high rates. Most scientists believe that the major reason for the rising temperature is the increase in concentration of greenhouse gases (GHGs) - water vapor, carbon dioxide, methane, nitrous oxide, ozone and chlorofluorocarbons (CFC) - in the atmosphere. A large fraction of the additional GHGs in the atmosphere can be attributed to the activities of man. For instance, the concentration of carbon dioxide has increased from 280 ppmv (parts per million on a volume basis) at the start of the industrial revolution to 370 ppmv today, and a significant fraction can be ascribed to the combustion of fossil fuels. CFCs, a potent GHG, are a man-made chemical. Anthropogenic emissions of the greenhouse gases can considerably enhance the greenhouse effect.
Scientific estimates suggest that the average annual temperatures might increase by 2-5°C during this century, and there could be significant changes in local and regional weather patterns. Such alterations in climate could have a variety of adverse effects, and in some instances, could even be beneficial to some species. Temperatures may increase more rapidly in some regions than in others, and wider ranges of high and low temperatures could occur. Changes in wind circulation and precipitation patterns could result in the increased humidity in some areas and droughts in others. Rising sea levels could inundate some coastal regions. More frequent and more severe storms and floods may occur. Soil erosion could increase substantially. New irrigation practices may be required. The quality of crops may undergo significant changes and this, in turn, could affect animal husbandry.
What can we do?
It is clear that man will have to adapt to these climate changes. However, by taking appropriate actions now we can also minimize the magnitude of the changes. We can reduce GHG emissions and increase GHG sequestration.
Carbon dioxide accounts for 70% of the anthropogenic emissions of greenhouse gases. We can reduce the rate of increase in the carbon dioxide concentration by reducing the combustion of fossil fuels, by using fossil fuels more efficiently, and by introducing the use of alternative and renewable energy sources. Oceans and biomass are major absorbers of carbon dioxide. Many of our forests are being cut, thus reducing the global carbon sink. We can reduce the rate of forest clearing, and we can also increase the carbon sink through afforestation measures.
There are numerous opportunities to reduce emissions and increase carbon sinks while simultaneously improving our environment and quality of life. Many examples of practices and programs being implemented by the Government of Ukraine and its international development partners are cited on this website. We hope that you will take the opportunity to learn what others are doing, and what you can do to address the global climate change problem.