According to the Commission's proposal -20º C would have been sufficient.
1	According	accord	VERB	V	VerbForm=Ger	6	case	_	_
2	to	to	ADP	E	_	1	fixed	_	_
3	the	the	DET	RD	Definite=Def|PronType=Art	4	det	_	_
4	Commission	commission	NOUN	S	Number=Sing	6	nmod	_	SpaceAfter=No
5	's	's	PART	PART	_	4	case	_	_
6	proposal	proposal	NOUN	S	Number=Sing	12	obl	_	_
7	-20º	-	NUM	N	NumType=Card	12	nsubj	_	_
8	C	Celsius	PROPN	SP	_	7	nmod	_	_
9	would	will	AUX	VM	Mood=Ind|Person=3|Tense=Past|VerbForm=Fin	12	aux	_	_
10	have	have	AUX	VA	VerbForm=Inf	12	aux	_	_
11	been	be	AUX	V	Tense=Past|VerbForm=Part	12	cop	_	_
12	sufficient	sufficient	ADJ	A	Degree=Pos	0	root	_	SpaceAfter=No
13	.	.	PUNCT	FS	_	12	punct	_	_
