Heald said although temperature and ozone are separately known to impact crop yields, "nobody has looked at these together".
1	Heald	Heald	PROPN	NNP	Number=Sing	2	nsubj	2:nsubj	Discourse=attribution-positive:20->22:1|Entity=(47-person-giv:inact-cf4-1-coref-Colette_Heald)
2	said	say	VERB	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	0	root	0:root	_
3	although	although	SCONJ	IN	_	9	mark	9:mark	Discourse=adversative-concession:21->22:0
4	temperature	temperature	NOUN	NN	Number=Sing	9	nsubj:pass	9:nsubj:pass|11:nsubj:xsubj	Entity=(58-abstract-new-cf1-1,3-coref(55-abstract-giv:act-cf2*-1-coref)
5	and	and	CCONJ	CC	_	6	cc	6:cc	_
6	ozone	ozone	NOUN	NN	Number=Sing	4	conj	4:conj:and|9:nsubj:pass|11:nsubj:xsubj	Entity=(5-substance-giv:act-cf3-1-coref)58)
7	are	be	AUX	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	9	aux:pass	9:aux:pass	_
8	separately	separately	ADV	RB	Degree=Pos	9	advmod	9:advmod	_
9	known	know	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	18	advcl	18:advcl:although	_
10	to	to	PART	TO	_	11	mark	11:mark	_
11	impact	impact	VERB	VB	VerbForm=Inf	9	xcomp	9:xcomp	_
12	crop	crop	NOUN	NN	Number=Sing	13	compound	13:compound	Entity=(22-object-giv:inact-cf5-2-coref(6-plant-giv:inact-cf6-1-coref)
13	yields	yield	NOUN	NNS	Number=Plur	11	obj	11:obj	Entity=22)|SpaceAfter=No
14	,	,	PUNCT	,	_	9	punct	9:punct	_
15	"	''	PUNCT	``	_	18	punct	18:punct	Discourse=context-circumstance:22->19:0|SpaceAfter=No
16	nobody	nobody	PRON	NN	Number=Sing|PronType=Neg	18	nsubj	18:nsubj	Entity=(59-person-acc:com-cf7-1-sgl)
17	has	have	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	18	aux	18:aux	_
18	looked	look	VERB	VBN	Tense=Past|VerbForm=Part	2	ccomp	2:ccomp	_
19	at	at	ADP	IN	_	20	case	20:case	_
20	these	this	PRON	DT	Number=Plur|PronType=Dem	18	obl	18:obl:at	Entity=(58-abstract-giv:act-cf1-1-ana)
21	together	together	ADV	RB	Degree=Pos	18	advmod	18:advmod	SpaceAfter=No
22	"	''	PUNCT	''	_	18	punct	18:punct	SpaceAfter=No
23	.	.	PUNCT	.	_	2	punct	2:punct	_
