Answer to Question 1
A major factor lies in the fact that many ecosystems are susceptible to drought; climate change will intensifies these risks. Likewise, given the tropical climate throughout much of central Africa it is believed that tropical diseases may increase as a result of changed climatic patterns. Problems stemming from rising sea levels will affect predominantly those locations along the West African coast.
Answer to Question 2
Answer: The octet rule is the generalization that atoms tend to gain, lose, or share electrons until they are surrounded by eight valence electrons. Although there are exceptions to the octet rule, it is a useful rule of thumb for understanding chemical bonding. It is because of the octet rule that two atoms of hydrogen will share their valence electrons in a covalent bond, and it also explains why sodium will give up an electron from its outer shell to a chlorine atom. The sodium thus goes from have one of eight valence electrons positions occupied to dropping down a valence level, gaining a positive charge, and having a full eight electrons in its new, lower valence level. The chlorine, in contrast, gains an electron to add to its pre-bonding seven electrons in its outer valence shell and also gain a full complement of eight. But that extra electron brings with it a negative charge, so chlorine is now an anion. Because opposites attract, the sodium cation and the negatively-charged chlorine are now bonded together into the ionic compound known as halite, or table salt.
The Climate System
Climate
Limiting factors restrain population growth
Historical Climate Change "تغير المناخ التاريخي"
Cave deposits as an indicator of environmental change
Climate History