Editing Cenozoic (section)

==Climate==
In the Cretaceous, the climate was hot and humid with lush forests at the poles, there was no permanent ice and sea levels were around 300 metres higher than today. This continued for the first 10&nbsp;million years of the Paleocene, culminating in the [[Paleocene–Eocene Thermal Maximum]] about {{Ma|55.5}}. Around {{Ma|50}}, Earth entered a period of long term cooling. This was mainly due to the collision of India with Eurasia, which caused the rise of the [[Himalayas]]: the upraised rocks eroded and reacted with {{CO2}} in the air, causing a long-term reduction in the proportion of this greenhouse gas in the atmosphere. Around {{Ma|35}}, permanent ice began to build up on Antarctica.<ref>{{cite book|last=Dartnell |first=Lewis |author-link=Lewis Dartnell |title=Origins:How the Earth Made Us |publisher=Bodley Head |location =London, UK|pages=9–10, 40 |year=2018|isbn=978-1-8479-2435-3 }}</ref> The cooling trend continued in the [[Miocene]], with relatively short warmer periods. When South America became attached to North America creating the [[Isthmus of Panama]] around {{Ma|2.8}}, the Arctic region cooled due to the strengthening of the [[Humboldt Current|Humboldt]] and [[Gulf Stream]] currents,<ref>{{cite web|url=http://www.whoi.edu/oceanus/viewArticle.do?id=2508|title=How the Isthmus of Panama Put Ice in the Arctic|work=Oceanus Magazine}}</ref> eventually leading to the glaciations of the [[Quaternary glaciation|Quaternary ice age]], the current [[interglacial]] of which is the [[Holocene]] Epoch.
Recent analysis of the geomagnetic reversal frequency, oxygen isotope record, and tectonic plate subduction rate, which are indicators of the changes in the heat flux at the core mantle boundary, climate and plate tectonic activity, shows that all these changes indicate similar rhythms on million years' timescale in the Cenozoic Era occurring with the common fundamental periodicity of ~13 Myr during most of the time.<ref>{{cite journal | last1 = Chen | first1 = J. | last2 = Kravchinsky | first2 = V.A. | last3 = Liu | first3 = X. | year = 2015 | title = The 13 million year Cenozoic pulse of the Earth | journal = Earth and Planetary Science Letters | volume = 431 | pages = 256–263 | doi = 10.1016/j.epsl.2015.09.033 | bibcode=2015E&PSL.431..256C}}</ref> The levels of carbonate ions in the ocean fell over the course of the Cenozoic.<ref>{{Cite journal |last1=Boudreau |first1=Bernard P. |last2=Luo |first2=Yiming |date=15 September 2017 |title=Retrodiction of secular variations in deep-sea CaCO3 burial during the Cenozoic |journal=[[Earth and Planetary Science Letters]] |volume=474 |pages=1–12 |doi=10.1016/j.epsl.2017.06.005 |issn=0012-821X |doi-access=free }}</ref>