Deforestation/Global Warming

Global warming
Climate change is happening faster than we actually think. Carrying on living the way we do and not thinking about what we can do to slow down climate change - and then doing it - can be dangerous. The earth could be getting warmer on its own, but many of the world's leading climate scientists think that the things people do are helping to make the earth warmer. Global warming refers to an increase in the earth's average near-surface and ocean temperatures. Global warming “facts” are hard to come by. One of the few facts that most scientists agree upon is that the current average temperature of Earth has risen over the past 100 years. According to most estimates, this increase in temperature amounts to about 0.4-0.8 °C (0.72-1.44 °F) over this period of time.

A warmer earth may lead to changes in rainfall patterns, a rise in sea level, and have a wide range of impacts on plants, wildlife, and humans. When scientists talk about the issue of climate change, their concern is about global warming caused by human activities. Of most significance to low lying areas (those that are very close to, or below sea level) is that global warming has an effect on ice - glaciers or icebergs melt, raising the level of the sea water. This rising sea level then affects the land as the sea floods these areas. Even if the sea water could be stopped from flooding an area, the land is made infertile by the salt: it cannot grow crops. Land in many arctic regions of the world is lost because of this.

People design homes for cold weather in Europe because most parts of Europe are very cold. With the change in global weather, these homes are now unsuitable because the weather is warmer and the houses are too warm.

Habitats and ecosystems
The animal and plant life living together in an area is called an ecosystem – all living things are included in and rely on these ecosystems. Many ecosystems depend on a delicate balance of rainfall, temperature and soil type. A rapid change in climate could upset this balance and seriously endanger many living things, crops and even human health.

Hybrid and Fuel Cell Cars
In an attempt to combat pollution and the release of carbon dioxide, car companies have, for years, been researching and testing alternative fuels for cars. They have specifically been looking at fuels that do not emit carbon dioxide when burned and those that emit lower levels of Carbon. There has also been a lot of research and development of electric and solar power cars, and hybrid cars. Out of these variants, there have been some successes with Hydrogen-based fuels, but the most successful type of car has been the hybrid. A hybrid car has a small petrol or diesel engine, and an electric motor which usually drives the wheels. The petrol or diesel engine is used to charge the batteries and provide more power to the wheels when required, and the cars usually use regenerative braking. Regenerative braking means that the electric motor in the car is used to slow the car down, but in the process generates electricity which then charges the batteries.

What are the Advantages of Hybrid Cars?
Most car companies manufacture hybrid cars. Some examples are Honda, Toyota, Nissan, Mazda, Ford, Chrysler, Lexus, etc. Hybrid cars are "cleaner" that traditional cars. They have much lower emissions, resulting in less pollution due to exhaust gas.

These hybrid cars can be as much as three times as efficient as normal petrol driven cars. Therefore, the primary advantages of electric cars over petrol cars are their lower emissions of carbon dioxide (CO2), and higher efficiency. Hybrid cars have a tendency to recapture significant amounts of energy during braking that is normally wasted as heat.

Finally, these cars are practical in that they can be fuelled using petrol or diesel that is purchased from the local gas/petrol station.

What are the Disadvantages of Hybrid Cars?
The expense is the primary disadvantage of hybrid cars. They are not only more expensive than their petrol equivalents, but they are also less powerful, so they do not perform as well and would not be suitable for towing a boat or trailer. They are also more complex and expensive to service and maintain, and require mechanics with specialist knowledge, to service them.

Ongoing Assessment
Teacher Notes