The effect of burning fossil fuels increasing the quantity of carbon dioxide in the atmosphere so that the earth warms up. This is a danger rather than a scientific certainty. There are fears that it could cause large-scale climatic changes, and raise the sea level through melting the polar icecaps, with catastrophic results. While the scale of these possible effects is uncertain, worry about them has given rise to a desire to restrict the use of fossil fuels and to the Kyoto Protocol of 1997.

• local minimum
• location
• lock-out
• locomotive principle
• logarithm
• logarithmic scale
• logistic curve
• log-linear function
• log-normal distribution
• log-rolling
• Lomé Convention
• London Inter Bank Offered Rate
• London International Financial Futures and Options Exchange
• long-dated security
• long position
• long rate
• long run
• long-run average cost
• long-run marginal cost
• long-run Phillips curve
• long-term interest rate
• long-term unemployment
• Lorenz curve
• loss
• loss leader