Carbon dioxide levels are constantly rising. In fact, the amount of CO2 on the Earth just reached a staggering level of 400 parts per million. But as linked as they are, CO2 levels and the Earth’s temperature do not rise at the same rate.
The amount of CO2 is increasing constantly, and the Earth just passed a landmark 400 parts per million concentration of atmospheric CO2, a level up from 280ppm before the Industrial Revolution – a 42.8% increase.
Contrary to popular thought, the amount of atmospheric CO2 does not double the greenhouse effect. So, why doesn’t the temperature rise at the same rate that CO2 increases? According to gpwayne at Skeptical Science, small amounts of CO2 and other greenhouse gases combine together to keep the Earth’s surface 33°Celsius (59.4°F) warmer than it would be without them, but just because CO2 levels have risen by 42% doesn’t mean the temperature will go up by 42% too.
The climate’s relationship with CO2 is very complex, and it is nearly impossible to separate the effects of natural changes from man-made ones over short periods of time – and by the Earth’s standards, a few hundred years is a short period of time. Temperature fluctuations happen due to cycles of warming and cooling in the oceans, but these fluctuations are hard to isolate from small changes in temperature caused by CO2 emissions which occur simultaneously.
Researchers are also studying tiny particle emissions from burning coal and wood since they may be having a long-term cooling effect. Scientists want to gather data over long periods in order to accurately measure changes over long periods. This will allow them to distinguish the effects of short natural variations from the effects of man-made CO2.