Question

project on global warming for economics

Answer 1

Increase in the concentration of carbon dioxide in the air is one of the major causes of global warming.

When the solar radiation fall on the earth's surface, a part of the radiation is absorbed and a part is reflected back into space. Greenhouse gases like carbon dioxide and methane present in the atmosphere absorbed some of the radiated heat.
These trapped radiation further warm the earth.

The trapping of the sun's radiation by the gases present in the earth's atmosphere is called greenhouse effect.
The causes of global warming are

1 Deforestation 
2 Burning of fossil fuels 
3 Biological degradation of organic matter present in sewage which release methane gas.