Claim: Elementary radiative-transfer calculations demonstrate that a natural surface global brightening amounting to ~1.9 Wm–2 over the 18-year period of study would be expected – using the IPCC’s own methodology – to have caused a transient warming of 1 K (1.8 F°).

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: The global temperature increase since the beginning of the industrial period (taken as 1750) is about 0.8 °C (1.4 °F), and the radiative forcing due to CO 2 and other long-lived greenhouse gases – mainly methane, nitrous oxide, and chlorofluorocarbons – emitted since that time is about 2.6 W/m2.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: Taking planetary heat uptake rate as the rate of ocean heat uptake estimated by the IPCC AR4 as 0.2 W/m2, yields a value for S of 2.1 °C (3.8 °F).

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: Solar irradiance is about 0.9 W/m2 brighter during solar maximum than during solar minimum, which correlated in measured average global temperature over the period 1959-2004.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: They judge that global mean surface air temperature has increased by 0.3 to 0.6 °C over the last 100 years, broadly consistent with prediction of climate models, but also of the same magnitude as natural climate variability.

Relevance (1 = gold evidence, 0 = mined hard negative): 1
Passage: The Paleocene–Eocene thermal maximum was an approximate 200,000 year long event where the global average temperature rose by some 5 to 8 °C (9 to 14 °F), and mid-latitude and polar areas may have exceeded modern tropical temperatures of 24–29 °C (75–84 °F).

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: The direct effect, via albedo, is a cooling effect that slows the overall rate of global warming: the IPCC's best estimate of the radiative forcing is −0.4 watts per square meter with a range of −0.2 to −0.8 W/m² but there are substantial uncertainties.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: In 2018 the IPCC published a Special Report on Global Warming of 1.5 °C which warned that, if the current rate of greenhouse gas emissions is not mitigated, global warming is likely to reach 1.5 °C (2.7 °F) between 2030 and 2052, risking major crises.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Positive radiative forcing results in warming.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Models referenced by the Intergovernmental Panel on Climate Change (IPCC) predict that global temperatures are likely to increase by 1.1 to 6.4 °C (2.0 to 11.5 °F) between 1990 and 2100.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: The observed 0.1% irradiance increase imparts 0.22 W/m climate forcing, which suggests a transient climate response of 0.6 °C per W/m.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Human-caused increases in greenhouse gases are responsible for most of the observed global average surface warming of roughly 0.8 °C (1.5 °F) over the past 140 years.

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Between the start of the Industrial Revolution in 1750, and the year 2005, the increase in the atmospheric concentration of carbon dioxide (chemical formula: ) led to a positive radiative forcing, averaged over the Earth's surface area, of about 1.66 watts per square metre (abbreviated W m).

Relevance (1 = gold evidence, 0 = mined hard negative): 0
Passage: Global Warming of 1.5 °C.