* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Human Impact on the Earth - Doral Academy Preparatory
Survey
Document related concepts
Transcript
Human Impact on the Earth Human Impact on the Earth Water Air Land Our Water Resources The water cycle is the continuous movement of water above, on, and below the Earth’s surface. It includes: Precipitation •Runoff •Evaporation •Condensation Our Water Resources Pollution is the introduction of harmful substances into the environment. Point-source pollution is pollution that comes from a single or easily traced point (such as a pipe). Our Water Resources Nonpoint-source pollution is pollution that comes from many places rather than a single point. It comes from places like yards, parks, farms, streets, and storm sewers and reaches bodies of water via runoff. Our Water Resources 65% of the Earth is water – but only 3% of that water is drinkable. Freshwater pollution comes from: • Fertilizer runoff • Bacteria from waste • Waste from factories • Pesticides Our Water Resources The Clean Water Act had a goal to make all surface water in the US safe enough for swimming and fishing by 1983. We have made progress – but that goal has still not been met. Our Water Resources Our oceans are also polluted, the most common sources being: • Trash • Sludge dumping • Oil spills The US spends more than $130 million a year to protect the ocean and beaches. The Air We Breathe Primary pollutants are pollutants that are put directly into the air by human or natural activity. •Exhaust, volcanic ash, smoke soot Secondary pollutants form from chemical reactions. •Smog The Air We Breathe Acid rain is rain, sleet, or snow that is highly acidic because of the burning of fossil fuels. The ozone hole formed when some chemicals added to the air reacted with the ozone layer. The Air We Breathe The Clean Air Act allows the Environmental Protection Agency (EPA) to control the amount of pollutants that can be released from any source. Burning of Fossil Fuels oil burning is responsible for about 30% of all carbon dioxide emissions to air. The main function of the carbon dioxide present in the atmosphere is to trap the heat obtained from sunlight and do not let it go beyond the atmosphere. It is because of the carbon dioxide in the atmosphere that our planet is warmer than any other planet of the solar system. On burning of fossil fuels, various types of gases like carbon dioxide, carbon monoxide, methane, nitrous oxide, are released. Saving Our Land Human causes of erosion: Deforestation or the process of clearing forests. Overgrazing removes large areas of grassland. Farming breaks up the soil. Saving Our Soil Desertification is a process by which human activity makes the soil infertile in areas where plants could once grow. Urbanization is also causes an impact on Earth, the more a population grows, the more resources are going to be used and the more the land is going to change.