Phanerozoic Eon 541 – 0 million years ago
Cenozoic Era 66 – 0 million years ago
Age of Mammals
- Quaternary Period 2.58 – 0 million years ago
Holocene/Anthropocene Epoch 11,700 to 0 years ago (Age of Man)
Pleistocene Epoch 2,588,000 to 11,700 years ago (Homo sapiens appear) - Neogene Period 23.03 – 2.58 million years years ago
O2 ca. 21.5 vol % (108 % of modern level)
CO2 ca. 280 ppm (1 times pre-industrial level)
Temp ca. 14 °C (0 °C above modern level) - Paleogene Period 66 – 23.03 million years ago
O2 ca. 26 vol % (130 % of modern level)
CO2 ca. 500 ppm (2 times pre-industrial level)
Temp ca. 18 °C (4 °C above modern level)
Graminoids – grass plant life appears
Mesozoic Era 252.17 – 66 million years ago
Age of Reptiles
Pangea supercontinent breaks up
Conifer plant life dominates
- Cretaceous Period 145 – 66 million years ago
O2 ca. 30 vol % (150 % of modern level)
CO2 ca. 1700 ppm (6 times pre-industrial level)
Temp ca. 18 °C (4 °C above modern level) - Jurassic Period 201.3 – 145 million years ago
O2 ca. 26 vol % (130 % of modern level)
CO2 ca. 1950 ppm (7 times pre-industrial level)
Temp ca. 16.5 °C (3 °C above modern level)
First small burrowing mammals appear - Triassic Period 252.17 – 201.3 million years ago
O2 ca. 16 vol % (80 % of modern level)
CO2 ca. 1750 ppm (6 times pre-industrial level)
Temp ca. 17 °C (3 °C above modern level)
Paleozoic Era 541 – 252.17 million years ago
Pangaea supercontinent forms
Cambrian Explosion occurs: Fish, arthropods, amphibians and reptiles develop
- Permian Period 298.9 – 252.17 million years ago
O2 ca. 23 vol % (115 % of modern level)
CO2 ca. 900 ppm (3 times pre-industrial level)
Temp ca. 16 °C (2 °C above modern level)
Sea level (above present day) Relatively constant at 60 m (200 ft) in early Permian; plummeting during the middle Permian to a constant -20 m (-66 ft) in the late Permian. - Carboniferous Period 358.9 – 298.9 million years ago
O2 ca. 32.5 vol % (163 % of modern level)
CO2 ca. 800 ppm (3 times pre-industrial level)
Temp ca. 14 °C (0 °C above modern level)
Sea level (above present day) Falling from 120m to present day level throughout Mississippian, then rising steadily to about 80m at end of period - Devonian Period 419.2 – 358.9 million years ago
O2 ca. 15 vol % (75 % of modern level)
CO2 ca. 2200 ppm (8 times pre-industrial level)
Temp ca. 20 °C (6 °C above modern level)
Sea level (above present day) Relatively steady around 189m, gradually falling to 120m through period - Silurian Period 443.8 – 419.2 million years ago
O2 ca. 14 vol % (70 % of modern level)
CO2 ca. 4500 ppm (16 times pre-industrial level)
Temp ca. 17 °C (3 °C above modern level)
Sea level (above present day) Around 180m, with short-term negative excursions - Ordovician Period 485.4 – 443.8 million years ago
Plant life begins to emerge from the oceans
O2 ca. 13.5 vol % (68 % of modern level)
CO2 ca. 4200 ppm (15 times pre-industrial level)
Temp ca. 16 °C (2 °C above modern level)
Sea level (above present day) 180 m; rising to 220 m in Caradoc and falling sharply to 140 m in end-Ordovician glaciations - Cambrian Period 541 – 485.4 million years ago
O2 ca. 12.5 vol % (63 % of modern level)
CO2 ca. 4500 ppm (16 times pre-industrial level)
Temp ca. 21 °C (7 °C above modern level)
Sea level (above present day) Rising steadily from 30m to 90m
Proterozoic Eon 2500–541 million years ago
Neoproterozoic Era 1000 – 541 million years ago
- Ediacaran Period 635 – 541 million years ago
O2 ca. 8 vol % (40 % of modern level)
CO2 ca. 4500 ppm (16 times pre-industrial level) - Cryogenian Period 720 – 635 million years ago
Snowball Earth
Mesoproterozoic Era 1.6 – 1.0 billion years ago
Rodinia supercontinent forms
Paleoproterozoic Era 2.5 – 1.6 billion years ago
Columbia supercontinent forms
Pre-Free Oxygen (atmospheric)
Archean Eon 4.0 – 2.5 billion years ago
Neoarchean Era 2.8 – 2.5 billion years ago
Oxygenic photosynthesis first evolved
Kenorland supercontinent appears
Mesoarchean Era 3.2 – 2.8 billion years ago
Vaalbara supercontinent breaks up
Paleoarchean Era 3.6 – 3.2 billion years ago
Vaalbara supercontinent forms
Eoarchean Era 4.0 – 3.6 billion years ago
Evidence of C12 enrichment
Hadean Eon 4.6 – 4.0 billion years ago
Earth’s crust formation
Surface temperature of 230 °C (446 °F) because of the atmospheric pressure of the heavy CO2 atmosphere
O2 = Mean atmospheric O2 content over period duration
CO2 = Mean atmospheric CO2 content over period duration
Temp = Mean surface temperature over period duration