O2, 150f
observational study, 32–33, 34
observations, 25
oceans
climate change and, 412–414
crust, A–13
plastic in, 120, 124, 137
rising sea levels, 407, 409, 412f
saltwater intrusion and, 265
solid waste in, 118f, 120
temperatures, 408
wastewater in, 266
water distribution and, 261f
I-15
OCSD. See Orange County Sanitation District
OCWD. See Orange County Water District
ODS. See ozone-depleting substances
OECD. See Organisation for Economic Co-operation and Development
oil, 360–379
in Canada, 379
consumption of, 375–377
conventional reserves of, 364–367
crude, 364, 366–367
definition, 362
environmental costs of, 370
formation of, 363f
fracking for, 371f
as limited resource, 364–365
in North Dakota, 362, 362f, 376f
peak, 365, 365f
proven reserves, 364, 364f
technology, 375
tight, 363
unconventional reserves of, 365, 369–372, 373f
unconventional types of, 372
wells, 365–366, 366f
oil palm plantation, 221f, 231f
oil sands, 372
oil shale, 372
oil spills, 368–369
one-child policy, China’s, 62–79, 70f
abortions and, 69–70
consequences of, 69–70, 73
contraception and, 70
exceptions to, 77
gender bias and, 75
human rights and, 70
resistance to, 69
sex ratio and, 73–74
sterilizations and, 69–70
100 Thing Challenge, 133
open dumps, 124
Orange County Groundwater Replenishment System (GWRS), 260, 261f, 274–275, 274f
Orange County Sanitation District (OCSD), 266–267
Orange County Water District (OCWD), 260, 265–266
orangutans, 223f, 228
Oreskes, Naomi, 422
organic agriculture, 318
organically grown crops conventional compared with, 337
organic food, 308f, 318–319
Organisation for Economic Co-operation and Development (OECD), 123f
organization of life, 142f
outdoor air pollution, 384–385, 386f, 389
overburden, 344, 345f, 346, 356
overconsumption, 76
overexploitation, 242f
overnutrition, 302
overpopulation, 66, 67
social justice issues associated, 72–73
Oxfam, 315
oxygen levels
in Biosphere 2, 150
in Gulf of Mexico, 280
ozone
breakdown of, 32
CI and, 30
CIO and, 41f
Earth’s protection by, 26–27
formation, 32
ground-level, 26, 385, 392f
stratospheric, 26
testing, 22f
ozone-depleting substances (ODS), 37f. See also specific substances
ozone depletion
Antarctic, 25–26, 38f
atmospheric chemistry of, 37–38
CFCs and, 28f, 32–35
effects of, 33, 36
hypotheses, 29–35
Montreal Protocol and, 36–37
policy change, 39
temperature and, 29, 37–38