1. We analyzed year 2000 data from 211 countries using the World Bank's method of distinguishing between low- middle- and high-income countries according to GNI/pop. We refer to low- and middle-income countries jointly as developing countries and high-income countries are considered industrialized or developed countries. Of the countries considered in this analysis approximately 75% fall into the former category. Countries are low-income if GNI/pop is less than U.S. $750 (69 countries including the Congo India and Indonesia); middle-income if GNI/pop is between U.S. $750 and $9250 (85 countries including Argentina Mexico and Turkey); or high-income if GNI/pop is greater than U.S. $9250 (57 countries including the United States Japan and Western Europe). We have also identified those countries comprising the poorest 10% (such as Cambodia Chad and Tajikistan) and the richest 10% (such as the United States Singapore and the United Kingdom). The developing-country group is heterogeneous in resource endowments and development conditions whereas classification as a developed country does not imply a preferred or final stage of development. GNI/pop is a convenient criterion among many metrics for levels of development and does not necessarily reflect development status. GNI GDP and population data for 2000 are drawn from the World Development Indicators 2002 published by the World Bank. Population GNI/pop and income categorization for all 211 countries are available at ( 31 ).
2. These numbers are based on year 2001 data from ( 29 ). Reserves include only resources that are identified as economically and technically recoverable with current technologies and prices. Other resources with foreseeable or unknown potential for recovery exist but are not included in this report because estimates are often highly speculative and unreliable particularly estimates of resources in developing countries. Reserve estimates tend to expand overall with time as technology increases the number of economically recoverable reserves.
3. These numbers are based on year 2001 data from ( 30 ). This estimate includes reasonably assured resources (RARs) identified by the IAEA and does not include other potential resources and secondary supplies from reprocessed uranium reenriched uranium and highly enriched uranium from the dismantlement of nuclear weapons. A list of reserves by country is available at ( 31 ).
4. However 42% of uranium used for nuclear electricity generation is currently supplied by secondary sources so the actual consumption of uranium reserves is less than this estimate suggests.
5. It should be noted that the three major fossil fuels are not perfect substitutes for each other particularly in the short term. Petroleum derivatives offer versatility in use and ease of transport that make them ideal for the transportation sector. Coal is the most abundant fossil fuel but generates the most airborne pollutants. Hence coal-fired electricity generation plants are gradually giving way to gas-fired plants. Natural gas is the cleanest-burning and most energy-efficient fossil fuel but supply is currently hindered by insufficient extraction and transport infrastructure such as regasification and storage facilities for importing liquefied natural gas from overseas.