The horrifying added factor is the high birth rate.
1	The	the	DET	DT	Definite=Def|PronType=Art	4	det	4:det	_
2	horrifying	horrifying	ADJ	JJ	Degree=Pos	4	amod	4:amod	_
3	added	add	VERB	VBN	Tense=Past|VerbForm=Part	4	amod	4:amod	_
4	factor	factor	NOUN	NN	Number=Sing	9	nsubj	9:nsubj	_
5	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	9	cop	9:cop	_
6	the	the	DET	DT	Definite=Def|PronType=Art	9	det	9:det	_
7	high	high	ADJ	JJ	Degree=Pos	9	amod	9:amod	_
8	birth	birth	NOUN	NN	Number=Sing	9	compound	9:compound	_
9	rate	rate	NOUN	NN	Number=Sing	0	root	0:root	SpaceAfter=No
10	.	.	PUNCT	.	_	9	punct	9:punct	_
