Appendix A: Units and Abbreviations, Prefixes

bbl

barrels

ºC

degree Celsius

g

gram

Ga

giga annum; billion years

h

hour

ha

hectare (10,000m²)

J

joule

L

liter

m

meter

Ma

mega annum; million years

mpg

miles per gallon

OM

order of magnitude

ppm

parts per million

s

second

t

tonne (metric ton)

W

watt

¥

yen

μ

micro

10⁻6

m

milli

10⁻3

h

hecto

10²

k

kilo

10³

M

mega

10⁶

G

giga

10⁹

T

tera

10¹²

P

peta

10¹⁵

E

exa

10¹⁸