Kyoto's still calling.

• Author: Buckley, Lila
• Position: EYE ON ECOLOGY - Kyoto Protocol and carbon emissions

IN A RECENT 12-MONTH SPAN, carbon emissions from the burning of fossil fuels climbed to more than 7,900,000,000 tons, a record high. Global emissions of carbon have been rising steadily since the late 18th century--and rapidly since the 1950s. In fact, annual emissions have quadrupled since the mid 20th century.

Three-fourths of global carbon emissions are the result of burning fossil fuels, namely coal, oil, and natural gas. The rest largely come from deforestation. Of the four major sectors contributing to these emissions, electricity generation--at 35%--accounts for the largest share; transportation and industrial processes, 20% each. The remaining 25% is produced by residential and commercial buildings. Two-thirds of the carbon emissions from fossil fuel combustion are emitted by just 10 nations. The U.S., with five percent of the world's population, is the largest contributor, accounting for nearly one-quarter of global emissions. China is second, with nearly 14%. Other major polluters are Russia, Japan, India, Italy, Canada, South Korea, Germany, and the United Kingdom.

Most of the growth in emissions in the coming decades, however, is expected to come from developing countries. While overall global carbon emissions have risen 13% since 1990, those in China have jumped 47%. Indeed, this one country accounts for nearly half of the global increase in emissions in the last decade.

As a result of the steady rise in carbon emissions, the amount of carbon dioxide in the atmosphere has increased by 31% since 1750--a rate unprecedented in the past 20,000 years. Nature usually absorbs a large portion of these emissions in oceans and forests, known as "carbon sinks," thereby slowing the rate of accumulation in the atmosphere. Recent trends, though, suggest that emissions am outpacing absorption. Over the past two decades, atmospheric C[O.sub.2] concentrations rose each year, on average, by 1.5 parts per million (ppm), but the last few years have seen unexplained and alarming jumps of up to 2.54 ppm and beyond. This suggests that the ability of the Earth's natural systems to mitigate the rise in carbon emissions is weakening.

The good news is that there are technologies able to cut carbon emissions. Switching from a reliance on carbon-intensive fuels like coal and oil to renewable energies and lower-carbon natural gas would account for huge reductions. Wind energy, for instance, currently produces enough carbon-free energy to provide electricity...