We assess evidence relevant to Earth's equilibrium climate sensitivity per doubling of
atmospheric CO2, characterized by an effective sensitivity S. This evidence includes …

Because of human action, the Earth has entered an era where profound changes in the
global environment are creating novel conditions that will be discernable far into the future …

2 Chapter 2 assesses observed large-scale changes in climate system drivers, key climate
indicators and 3 principal modes of variability. Chapter 3 considers model performance and …

Variations in Earth's orbit pace the glacial-interglacial cycles of the Quaternary, but the
mechanisms that transform regional and seasonal variations in solar insolation into glacial …

During the Mid-Pleistocene Transition (MPT; 1,200–800 kya), Earth's orbitally paced ice age
cycles intensified, lengthened from∼ 40,000 (∼ 40 ky) to∼ 100 ky, and became distinctly …

The Piacenzian stage of the Pliocene (2.6 to 3.6 Ma) is the most recent past interval of
sustained global warmth with mean global temperatures markedly higher (by~ 2–3 C) than …

The geological record encodes the relationship between climate and atmospheric carbon
dioxide (CO2) over long and short timescales, as well as potential drivers of evolutionary …

Over the past eight hundred thousand years, glacial–interglacial cycles oscillated with a
period of one hundred thousand years ('100k world'). Ice core and ocean sediment data …

Current atmospheric CO2 concentration is known to be higher than it has been during the
past∼ 800 ky of Earth history, based on direct measurement of CO2 within ice cores. A …

Connections between glaciation, chemical weathering, and the global carbon cycle could
steer the evolution of global climate over geologic time, but even the directionality of …