Table 1. Biogenic benzenoid volatile compounds.

Compound	Biogenic driver	Biogenic (MEGAN v2.1)		Biogenic (possible range)	Anthropogenic (EDGAR)	Biogenic SOA (mostly low NOx)	Anthropogenic SOA (mostly high NOx)
		Emission factor	Global emission	Global emission	Global emission	Potential global source range	Potential global source
		μg m2 h−1	Tg y−1	Tg y−1	Tg y−1	Tg y−1	Tg y−1
toluene	multiple	9	1.5	1 to 6b	7.6	0.3 to 3.0	0.6 to 4.5
benzene	multiple	0	0	0.1 to 1	6.1	0.04 to 0.4	0.5 to 3.3
xylene	multiple	0	0	0.1 to 0.5	5.2	0.04 to 0.2	0.4 to 2.2
othera		37	6.6	3 to 33	5.5	1.0 to 11	0.2 to 1.8
Total		46	8.1	4 to 40	24.4	1.4 to 15	2.0 to 12
aother biogenic benzenoids
homosalate	sunscreen	8.4	2.0	1 to 10
ethylhexenyl salate	sunscreen	4.2	0.98	0.5 to 5
cymene <para->	foliar, floral	7.5	0.9	0.5 to 5
cymene <ortho->	foliar, floral	4.5	0.54	0.2 to 3
methyl salicylate	stress	9	1.5	0.3 to 3
p-cymenene (dimethyl styrene)	unknown	0.3 to 0.6	0.05	<0.1 to 1
estragole (methyl chavicol)	floral, fruit conifer	0.9 to 1.65	0.18	0.1 to 5
indole	stress	0.6	0.1	<0.1 to 0.2
benzaldehyde	stress	0.15	0.05	<0.1 to 0.2
methyl benzoate	unknown	0.15	0.05	<0.1 to 0.1
m-cymenene	unknown	0.3	0.04	<0.1 to 0.1
phenylacetaldehyde	unknown	0.15	0.05	<0.1 to 0.1
anisole	floral	0.15	0.05	<0.1 to 0.1
benzyl acetate	floral	0.3	0.1	<0.1 to 0.2
benzyl alcohol	floral	0.15	0.05	<0.1 to 0.1
eugenol	stress	0	<0.02	<0.1 to 0.2
cinnamic acid	stress, floral	0	<0.02	<0.1 to 0.1
coniferyl alcohol	unknown	0	<0.02	<0.1 to 0.1
chavicol	floral	0	<0.02	<0.1 to 0.1
safrole	unknown	0	<0.02	<0.1 to 0.1
ethyl cinnamate	unknown	0	<0.02	<0.1 to 0.1
salicylic aldehyde	stress	0	<0.02	<0.1 to 0.2

Compared are emission factors and global emission estimates used by MEGAN, and possible global ranges based on current understanding. In addition, comparison with anthropogenic benzenoid compounds is given.

^aother biogenic benzenoids,

^bincludes emissions from picoplankton and E. hux of 1.6 Tg y⁻¹.