Claim: The Schmittner et al. study finds low probability of both very low and very high climate sensitivities, and its lower estimate (as compared to the IPCC) is based on a new temperature reconstruction of the Last Glacial Maximum that may or may not withstand the test of time.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: This is the "likely" range (greater than 66% probability), based on the expert judgement of the IPCC's authors.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: For constant humidity they computed a climate sensitivity of 2.3 °C per doubling of CO2 (which they rounded to 2, the value most often quoted from their work, in the abstract of the paper).

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: The IPCC Fifth Assessment Report reverted to the earlier range of 1.5 to 4.5 °C (2.7 to 8.1 °F) (high confidence) because some estimates using industrial-age data came out low.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: Compared to the previous report, the lower bounds for the sensitivity of the climate system to emissions were slightly lowered, though the projections for global mean temperature rise (compared to pre-industrial levels) by 2100 exceeded 1.5 °C in all scenarios.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: The Intergovernmental Panel on Climate Change (IPCC, 2007) have produced a range of projections of what the future increase in global mean temperature might be.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Climate sensitivity can be estimated by using reconstructions of Earth's past temperatures and levels.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: In the context of global warming, different measures of climate sensitivity are used.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: In 2013, Hansen authored a paper called "Climate sensitivity, sea level and atmospheric carbon dioxide," in which he estimated climate sensitivity to be (3±1)°C based on Pleistocene paleoclimate data.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: In preparation for the 2021 6th IPCC report, a new generation of climate models are being developed: some show climate sensitivity around , meaning temperature can rise by 6.5 - 7 degree by 2100 in the worst socio-economic scenario ("SSP5 8.5 – rapid economic growth driven by fossil fuels without mitigation").

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Ljungqvist 2010 "A New Reconstruction of Temperature Variability in the Extra-Tropical Northern Hemisphere During the Last Two Millennia".

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Different approaches to the task of estimating climate sensitivity from the LGM are taken.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Over the last 800,000 years, climate sensitivity has been found to be larger in cold periods than in warm periods.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: For coupled atmosphere-ocean global climate models (e.g. CMIP5) the climate sensitivity is an emergent property : it is not a model parameter, but rather a result of a combination of model physics and parameters.