As the various numbers get swirled around, and agreements are made, it is revealing to have the back-story from a few days ago, as this article from the Wall Street Journal provides.
An excerpt.
“Imagine a "dream" agreement emerging from Copenhagen next week: The U.S. agrees to cut greenhouse emissions 80% by 2050, as President Barack Obama has been promising. The other developed countries promise to cut emissions by 60%. China promises to reduce its CO2 intensity by 70% in 2040. Emerging economies promise that in 2040, when their wealth per capita has grown to half that of the U.S., they will cut emissions by 80% over the following 40 years. And all parties make good on their pledges.
“Environmental success, right? Wrong. Even if the goals are all met, emissions will continue rising to nearly four times the current level. Total atmospheric CO2 will rise to near 700 parts per milion by 2080 (the current level is 385), and—if the U.N. Intergovernmental Panel on Climate Change (IPCC) models are right—global temperature will rise about six degrees Fahrenheit at mid latitudes.
“The reason is that most future carbon emissions will not come from the currently industrialized world, but from the emerging economies, especially China. And China, which currently emits 30% more CO2 per year than the U.S., has not promised to cut actual emissions. It and other developing nations have promised only to cut their carbon "intensity," a technical term meaning emissions per unit of GDP.
“China claims it is already cutting CO2 intensity by 4% a year as part of its five-year plan. President Hu Jintao has hinted that at Copenhagen China will offer to continue such reductions. By 2040, that will add up to a 70% reduction in intensity.
“Sounds good, but here's the catch: With 10% annual growth in China's economy, a 4% cut in intensity is actually a 6% annual increase in emissions. India and other developing countries have similar CO2 growth. That 6% yearly increase is what is shown in the nearby chart.
“True, China's CO2 per capita is only a quarter of the U.S. emissions rate. But warming doesn't come from emissions per capita, it comes from total emissions.
“China's carbon intensity is now five times that of the U.S.; it is extremely carbon inefficient. By the time the Chinese cut emissions intensity by 45%, its yearly total will be over twice that of the U.S. And in the proposed Copenhagen dream scenario, by 2025 China's emissions will actually surpass those of the U.S. per capita.
“If the issue is rising emissions in the next several decades, the bottom line is simple: The developed world is rapidly becoming irrelevant.
“Every 10% cut in the U.S. is negated by one year of China's growth. By 2040 China could be the most economically dominant nation on earth. The West might be able to cajole it, but won't be able to impose sanctions on China. Temperature will be at the mercy of the newly powerful economies.”