New evidence from analyzing fossil plankton shells has revealed that CO2 concentration in the Earth’s atmosphere was about triple current levels around 52 million years ago. It then declined to levels close to current atmospheric CO2 concentration 34 million years ago when Antarctica began to glaciate.
A recent study, published in Nature, reports on how anonymized data from three quarter of a million global smart phones was used to detect and map physical inactivity around the world. The study is an outstanding example of the type of scientific analyses that is possible using human beings as sensors.
From 2011 until early 2017, EnvironmentCounts was published using TikiWiki. This link will take you to more than a hundred additional EC articles.
Approximately 800,000 years ago something changed in the Earth’s climate system that led to the climate then following a series of approximately 100,000 year cycles. Small, predictable changes in the Earth’s orbit about the Sun act as triggers for the glacial and interglacial periods, but other factors such as ice sheet volume, CO2 concentration, and biological feedback mechanisms are also involved.