Effects of the changing magnetic field on the climate
Answers
The increase in atmospheric CO2 concentration has been thought to be the main cause of climatic changes at these high altitudes. This study suggests that magnetic field changes that have taken place over the past century are as important.
Both increasing levels of CO2 and changes in the Earth's magnetic field affect the upper atmosphere, including its charged portion, also known as the ionosphere.
While CO2 causes heat to be trapped in the lower atmosphere, it actually cools the upper atmosphere. The simulations show that the increase in CO2 concentration over the past 100 years has caused the upper atmosphere, at around 300 km altitude, to cool by around 8 degrees. At the same altitude, changes in the Earth's magnetic field caused a similar amount of cooling over parts of North America, but caused a warming over other parts of the world, with the strongest warming, of up to 12 degrees, located over Antarctica.