1. Environmental Problems

The environment is our physical surroundings. This includes both human (man-made), social and physical (natural) features. Natural features include soil, the atmosphere, vegetation and wildlife. Human features include housing, transport and industry. Social features include things such as culture, language and political systems.

Geographers are concerned about human action in the environment. Human interference with the environment causes problems such as soil erosion, global warming and acid.

You may ask how we as individuals can have an impact on the environment. Our actions can help to increase and decrease the problems highlighted above. For example turning off lights that are not being used helps to reduce global warming.

Questions：

1．What is the environment?

2．How can we help to decrease the global warming problems?

Global Warming

Global warming is the worldwide warming of the atmosphere.To understand global warming you first need to know about the greenhouse effect. The greenhouse effect is a natural phenomenon that controls the balance of heat within the earth's atmosphere. It is the process whereby the natural layer of gases in our atmosphere trap a small percentage of the sun's radiation reflected from the earth's surface. Without the greenhouse effect, the average surface temperature would be about -18 degrees Celsius.

Global warming is caused by the increases in the amount of carbon dioxide and other gases being released into the atmosphere by the burning of fossil fuels. These gases add to the natural greenhouse effect. Causing global temperatures to rise.

Questions：

1.What is global warming? 2.What causes global warming?

Atmospheric particulate matter

In recent years,our country appear much haze weather,which is now often referred to PM2.5.Specifically,PM2.5 is in the atmosphere of diameter less than or equal to 2.5 micron particles,which is also known as enters the lung particle matter.Its diameter is less than the thickness of a human hair 1/20.

Atmospheric particulate matter- also known as particulates or particulate matter(PM) - are tiny pieces of solid or liquid matter associated with the Earth's atmosphere. They are suspended in the atmosphere as atmospheric aerosol, a term which refers to the particulate/air mixture, as opposed to the particulate matter alone. However, it is common to use the term aerosol to refer to the particulate component alone.

Some particulates occur naturally, originating from volcanoes, dust storms, forest and grassland fires, living vegetation, and sea spray. Human activities, such as the burning of fossil fuels in vehicles, power plants and various industrial processes also generate significant amounts of particulates. Coal combustion in developing countries is the primary method for heating homes and supplying energy.

Particulate matter emissions are highly regulated in most industrialized countries. Due to environmental concerns, most industries are required to operate some kind of dust collection system to control particulate emissions. These systems include inertial collectors (cyclone collectors), fabric filter collectors (baghouses), wet scrubbers, and electrostatic precipitators.

Questions: 1、

1.What is Atmospheric particulate matter? 2.What causes global warming?