Causes of Global Warming

Video Transcript

"Hi I'm Brian with ericksontutoring.blogspot.com and today we are going to discuss some of the causes of global warming. So in the 20th century the Earth has warmed by approximately 1.5 degrees Fahrenheit. This really is not up for debate the fact is backed up by a lot of scientific data. In general the Earth is kept warm by something called the Greenhouse Effect. There are certain gases in our atmosphere that trap in heat that has been reflected and bounced radiated off the Earth that keeps heart in and keeps our planet approximately 33 degrees Celcius warmer than what it otherwise would be without that atmospheric, without the Greenhouse Effect. So there is a natural Greenhouse Effect which keeps our planet inhabitable. What we're seeing now though is that the Greenhouse Effect is being increased and exacerbated by both natural and mostly human actions so we'll take a look at some of the causes. First of all there are a couple natural causes for Global Warming, the changes in solar radiation so the output of the sun does change in cycles. It changes in about eleven year cycles. This has contributed to some of the warming in the past but it doesn't match up with the current trends that are seen so it is not really an explanation for the current Global Warming. Second volcanic dust so particles that are omitted when volcanoes erupt tend to put sulfates and things in the air which actually make short term cooling patterns. We see this and we know when volcanoes erupt so we can often associate them with short term cooling patterns. Finally as I said before there are natural greenhouse gases and those contribute to the Greenhouse Effect which keeps our planet inhabitable. Now there is also several human causes or anthropogenic causes of the current Global Warming and this is really the reason for all of the hype and all of the media coverage. There are two main causes that contribute to Global Warming. First you have increases in greenhouse gas, greenhouse gases. These are usually put in the air by burning fossil fuels so when you burn things that were buried in the Earth you release a lot of methane, carbon dioxide, nitrous oxide, sulfur, sulfur oxides and things like that. Those are greenhouse gases and we know that they trap heat in. In addition land use changes, deforestation, urbanization, these 1) effect how much greenhouse gases are able to be captured and 2) they also create more pockets of heat so if you go to a major city like New York City it is going to be hotter there. It is a heat island effect and it is because of all the asphalt and pavement and the lack of vegetation it's warmer there, no one is going to argue that one. In addition humans also put other pollutants in the air. Some of those have a cooling effect such as sulfates but in general the pollution from humans has contributed to Global Warming. So this has been a brief discussion of the causes of Global Warming. There is very little scientific doubt that it is being human caused at this point and I encourage you to find out more and take some action."