Natural greenhouse effect
- Sunlight comes through the atmosphere and reaches the Earth.
- Invisible infrared radiation is reflected back to space.
- Some gases in the atmosphere (greenhouse gases) don’t let the radiation escape and reflect it back to Earth.
- The Earth keeps warm.
Anthropogenic greenhouse effect
Too much greenhouse effect
CO2 concentration in the atmosphere has increased due to an increased industrial activity (fossil fuel burning) and other human activities such as cement production and tropical deforestation. Elevated CO2 levels will increase global temperature.
- How temperature will increase in the future?
- Which type of greenhouse effect keeps the Earth at it optimum temperature?
Sources of information
Images from Google
Posted in Uncategorized on May 27, 2011
The scarlet macaws are endangered because people catch them for pets, others because they cut the trees where they live. People also kill them because they want their feathers or the macaw’s body
(They are imported in large quantities to the USA)
In 1798, he published the Principle of Population that states that if man multiplies more rapidly than the food supply, competition for existence would result. He said that as more offspring are born, a more competitive nature would arise because fewer resources will be available.
Sara Escribano M. 4ºA
- To establish paternity and maternity
- In criminal identification and forensics: Genetic evidences left at the scene of a crime can be compared, through VNTR patterns, with the DNA of a criminal suspect to determine guilt or innocence.
- Personal Identification
Opposite to popular belief, GMOs or transgenics are not harmful to our health or the environment and neither unlabeled.
Genetic engineering can now carry out in few years and in a controlled way , which previously could take decades or centuries, or achieve effects that before were only in the dreams of the farmers. Thanks to GMOs, crops can be made more resistant to pest outbreaks or weather, and animals in farms can produce higher quality foods, therefore, both farmers and buyers are benefit.
Nowadays starvation is the leading cause of death worlwide, this may be because in many poor countries even they can sow, their crops have lack of nutrients. Stientists to fight against hunger have, for example, developed rice and wheat with an extra charge of vitamin A.
Transgenic plants are being used to produce vaccines, proteins and other pharmaceutical products.
GMOs will reduce the environmental impact of food production because no hervicides or pesticides will be needed.
The unlabeling of transgenics is not true at all, we can perfectly recognize labelled organic food in our supermarkets.
In conclusion GMOs are fully useful and completely necessary.