History

• Industrial smokestacks churning out CO2
  
  The Industrial Revolution marked a turning point in history, when businesses suddenly had the ability to manufacture at an unprecedented rate. Fueling that ability was the use of fossil fuels, at first coal and then oil and natural gas. While it led to the modern age, it also led to climate change, something that the early industrial pioneers likely never considered (or would even have thought possible). Even at the beginning of the twenty-first century, the idea that humans have impacted the global climate is a difficult one for some people to accept.
  
  

Types

• Human effects on global warming fall into two general categories: emissions and deforestation. These two deliver a one-two punch, with emissions putting more CO2 into the atmosphere, and deforestation making it harder for the biosphere to take that extra CO2 out of the atmosphere. CO2, or carbon dioxide, is the gas that most scientists believe drives global warming, and the levels have increased significantly since the advent of modern industry. While the developed world is the biggest contributor to emissions, it is deforestation that hits the less-developed nations of the world, making it a global issue.
  
  

Emissions

• Air pollution from traffic
  
  Carbon emissions are the largest human contribution to global warming, by some estimates accounting for nearly three-quarters of the human effect on global warming. Emissions come from the burning of fossil fuels such as coal, oil and natural gas. Because these are made from organic material, when they burn they release carbon into the atmosphere, most of it in the form of CO2. With the vast numbers of cars on the road, and the large number of industrial plants--a majority of which rely heavily on fossil fuels to run--the amount of CO2 humans have put into the air has increased, leading in turn to an increase in the global temperature.
  
  

Deforestation

• Deforestation in Bolivia
  
  Deforestation is the other major human-related cause of global warming. By cutting down trees and other plant life and replacing it with roads, cities and other man-made structures, human activity has reduced the ability of the biosphere to remove CO2 from the atmosphere. While deforestation is most commonly associated with places like Brazil, it should be noted that the forests of North America were being (and continue to be) cut down at the same time as the Industrial Revolution was booming. In addition, cities and other man-made structures tend to absorb heat, further helping to warm the climate.
  
  

Considerations

• Despite the controversy stirred up by politics, the general consensus among the scientific community is that humans are having an effect on global warming. While the planet has been through warming and cooling cycles in the past, the recent increase in CO2 levels is most likely a result of human activity--specifically emissions and deforestation. This also means, however, that a change in human behavior with regard to emissions and deforestation might help to reduce the human effect on global warming. This may help alleviate the amount of global warming and reduce the overall impact on the climate.