For the past few   
years
 a tremendous increase in the Add a comma
,years
population
 has been observed. Some believe that Use synonyms
population
 expansion is the prime concern of Use synonyms
the 
mankind. I agree with it completely. In the following paragraphs, I will put forth my views in detail.
To commence with, Correct article usage
apply
principal
 reason for the increased birth rate is Add an article
the principal
a principal
lack
 of sex education. To elaborate, Correct article usage
the lack
people
 do not have proper knowledge about Use synonyms
safe
 period to avoid unwanted pregnancy along with the drawbacks of frequent Add an article
the safe
child bearing
. Correct your spelling
childbearing
Thus
Linking Words
Change the article
 a 
 the 
number
 of children would be increased in each family. Use synonyms
In addition
, certain religions command Linking Words
people
 to  increase their Use synonyms
number
 since it is the obligation of man to god. To explain, according to Use synonyms
such
 doctrines, the creator would punish his disciples for not having enough offsprings. Linking Words
For example
, Linking Words
Christian
 and Correct article usage
the Christian
Islam
 faith inculcate Add the possessive form
Islam's
such
 beliefs in their followers. 
Linking Words
Therefore
 growth in Linking Words
Use synonyms
number
 of Change the article
a number
the number
people
 due to Use synonyms
above
 reasons could have a negative impact on Correct article usage
the above
the 
mankind. To elaborate, Correct article usage
apply
firstly
, with uncontrolled Linking Words
population
 expansion, resources to satisfy the needs of Use synonyms
emerging
 Add an article
the emerging
population
 is inadequate. Use synonyms
Consequently
 results in unhealthy competition between individuals for proper food, Linking Words
accomodation
 and sanitation. Correct your spelling
accommodation
Secondly
 Linking Words
excess
 Change the article
an excess
the excess
number
 of Use synonyms
people
 could end up on aggressive environmental pollution which could Use synonyms
aggrevate
 the current situation. Correct your spelling
aggravate
For instance
, according to the UN, Linking Words
primary
 reason behind the pollution is the Add an article
the primary
population
 size. Use synonyms
Thus
 Linking Words
it 
could be reiterated the deleterious effects of Correct pronoun usage
apply
population
 density on mankind.
To conclude, in my opinion, Use synonyms
population
 expansion Use synonyms
have
 detrimental effects on humanity. Change the verb form
has
This
 is due to unhealthy competition as well as encroachment on biodiversity.Linking Words