Human Influences On Environment Flashcards
What gases are involved in acid rain
How is acid rain formed
Burning fossil fuels can give many gases. For example, sulfur dioxide and nitrogen oxides (NOx gases).
The sulfur dioxide combined with water droplets in clouds to form sulfuric acid.
The nitrogen oxides combine with water to form nitric acid.
When the rain falls, it is more acidic than usual and is called acid rain.
DIAGRAM OF ACID RAIN
IN PHOTOS IT IMPORTANT
The effect of acid rain on living organisms (4)
- Acid damages cells and delicate tissues. If it breathed in, the acid can damage the delicate tissues lining the lungs.
- Plants may have their leaves damaged which means it can no longer photosynthesise or grow well.
- Animals with soft skin (for example fishes and amphibians) may have their skins damaged by the acid rain falling where they live
- Single celled organisms (such as protoctists) are even more likely to be damaged.
The indirect effect of acid rain on the ecosystem
- In soil, it can cause some mineral ions to dissolve in the soil water, which is called leaching. These ions are poisonous to some species.
- Others may be more easily washed out of the soil, away from plants that need them = plant growth is reduced.
- Damaging some organisms in a food web has an impact on other organisms because organism in an ecosystem are interdependent (of two or more people or things dependent on each other).
A diagram to summarise the key features of the greenhouse effect
LOOK IN PHOTOS ITS IMPORTANT
What would life on Earth be like without the existence of greenhouse effect?
The greenhouse effect is normal and is important for life on Earth. Without it, it is estimated that the surface of the Earth would be about 33 degrees Celsius cooler than it is now. All water on Earth would be frozen, and very little life could exist in these conditions.
What are the greenhouse gases and where have they come from?
Greenhouse gases play an important role in keeping the Earth’s surface warm. They include:
o Water vapour – which is water that has evaporated from the Earth’s surface
o Carbon dioxide – produced naturally from respiration of living organisms
o Nitrous oxide (N2O) – released naturally from soil and water due to soil bacteria
o Methane – produced during the decay of organic material, such as in swamps and in the digestion of food in the alimentary canal.
o CFCs (chlorofluorocarbons) – artificial chemicals produced for use in cooling systems in fridges and in aerosols, these are no longer widely used because they can damage the ozone layer in the atmosphere.
Greenhouse effect
The warming effect caused by greenhouse gases in the atmosphere that prevent some of the heat energy radiated by the Earth’s surface and prevent it escaping into space
How does the greenhouse effect explain the huge variation in temperature between Venus and Mars
Mars has a thin atmosphere and although it’s composed mainly of carbon dioxide it’s effect as a greenhouse gas is limited. The average surface temperature on Mars is about -55 degrees Celsius, varying from about 27 degrees Celsius during the day at the equator to -143 degrees Celsius at the poles at night.
Venus had a much denser atmosphere than Earth, consisting mainly of carbon dioxide with clouds of sulfur dioxide. These gases create a very strong greenhouse effect, heating the surface of Venus to an average of around 460 degrees Celsius.
What is the enhanced greenhouse effect and how are humans contributing to this effect
Human activities have increased and are increasing the proportion of some greenhouse gases in the Earth’s atmosphere:
o Carbon dioxide is increasing as a result of the combustion of fossil fuels
o Nitrous oxide is increasing partly from the combustion of fossil fuels, but mainly from the breakdown of artificial nitrogen fertilisers which are added to fields to encourage crop growth.
o Methane is increasing as a result of the increasing numbers of people and farm animals that we keep, and from the release of the gas from artificial wetlands such as rice paddy fields.
o CFCs are still in the atmosphere due to their use in fridges and aerosols.
Average global surface temperature has been rising over the past few centuries. However, many scientists are certain that the recent increases in temperature are the result of increased emissions of greenhouse gases from human activity, leading to an enhanced greenhouse effect resulting in global warming.
(To summarise, enhanced greenhouse effect is an increase in the greenhouse effect, most likely caused by the release of additional greenhouse gases from human activity).
How does deforestation contribute to the enhanced greenhouse effect?
Deforestation means that we now have less trees and forests and therefore less carbon dioxide is being removed from the atmosphere. Carbon dioxide is a greenhouse gas, and having more of it means that heat is more easily trapped by these greenhouse gases. This heat is radiated back to the Earth, causing it to heat up = enhanced greenhouse effect.
What are 5 possible consequences of global warming?
1) The number and strength of storms
2) Drought
3) Flooding as a result of increased rainfall and rising sea levels
4) Hotter summers and warmer winters
5) Cooler, wetter summers and colder winters
Global warming definition
Global warming – warming of the Earth’s surface and atmosphere, possibly as a result of an enhanced greenhouse effect.
