|carbon dioxide emission from factories|
What are the reasons the cause global warming?
Scientists and researchers have spent years figuring out what causes global warming. They have looked at the natural cycles and events that are known to impact climate changes. But the amount and pattern of warming that's been measured cannot be estimated by these factors alone. The only way to explain the pattern is to include the effect of greenhouse gases emitted by us humans.
One of the first things that scientists and researches figured out is that there are several greenhouse gases responsible for warming, and humans emit them in many ways. Most come from the combustion of fossil fuels in cars, industries and electricity production. The gas responsible for the most warming is carbon dioxide, also called CO2. Other contributors include methane released from landfills and agriculture, nitrous oxide from fertilizers, gases used for refrigeration and industrial processes, and the loss of forests around the world that would otherwise store CO2.
|melting ice due to warming|
In order to understand the consequences of all the gases together, researchers usually discuss all green house gases with regards to the comparative amount of CO2. Since 1990, pollution have gone up by about 6 billion metric tons of "carbon dioxide equivalent" globally, more than a 20 percent increase.
Article reference: nationalgeographic.com
Image credits: nationalgeographic.com, telegraph.co.uk