Albedo
Number of papers: 10 (1 not counted because it’s also on the greenhouse gas page)
Clouds independently appear to have as much or greater effect than man-made CO2 on radiative forcing — World Journal of Advanced Research and Reviews, 2022; Michael Jonas
“The patterns of behaviour of clouds, both for cloud area and cloud optical thickness, are studied over the period of available data, 1983 to 2017. There was a decrease in cloud cover over the study period, while global surface temperatures increased. The patterns of clouds and temperature indicate that the cloud cover decrease could not have been caused by the increased surface temperature. The clear implication is that the decrease in global cloud area must have been caused by some other unspecified factor, and was not caused directly or indirectly by CO2.”
Roles of Earth’s Albedo Variations and Top-of-the-Atmosphere Energy Imbalance in Recent Warming: New Insights from Satellite and Surface Observations — Geomatics, 2024; Nikolov & Zeller
“Our analysis revealed that the observed decrease of planetary albedo along with reported variations of the Total Solar Irradiance (TSI) explain 100% of the global warming trend and 83% of the GSAT interannual variability as documented by six satellite- and ground-based monitoring systems over the past 24 years. Changes in Earth’s cloud albedo emerged as the dominant driver of GSAT, while TSI only played a marginal role.”
Recent global temperature surge intensified by record-low planetary albedo — Science, 2024; Goessling et al.
“In 2023, the global mean temperature soared to almost 1.5K above the pre-industrial level, surpassing the previous record by about 0.17K. Previous best-guess estimates of known drivers including anthropogenic warming and the El Niño onset fall short by about 0.2K in explaining the temperature rise. Utilizing satellite and reanalysis data, we identify a record-low planetary albedo as the primary factor bridging this gap.”
Observational Assessment of Changes in Earth’s Energy Imbalance Since 2000 — Nature Scientific Reports, 2024; Loeb et al.
This is an extremely important paper, since Loeb’s previous paper was an “attribution study” showing CO2 was responsible for warming. He now says “We find that large decreases in stratocumulus and middle clouds over the sub-tropics and decreases in low and middle clouds at midlatitudes are the primary reasons for increasing ASR trends in the northern hemisphere (NH). These changes are especially large over the eastern and northern Pacific Ocean, and coincide with large increases in sea-surface temperature (SST). The decrease in cloud fraction and higher SSTs over the NH sub-tropics lead to a significant increase in OLR from cloud-free regions, which partially compensate for the NH ASR increase. Decreases in middle cloud reflection and a weaker reduction in low-cloud reflection account for the increase in ASR in the southern hemisphere, while OLR changes are weak. Changes in cloud cover in response to SST increases imply a feedback to climate change yet a contribution from radiative forcing or internal variability cannot be ruled out.”
The 2023 Record Temperatures: Correlation to Absorbed Shortwave Radiation Anomaly — Science of Climate Change, 2024; Antero Ollila
“The total Radiative Forcing (RF) according to the AR6 was 2.70 Wm-2 for the period 1750-2019. This can be compared to the change in the ASR, which was 2.01 Wm-2 from the year 2000 to the year 2023. This finding means that natural climate drivers have altogether an important role in recent global warming.”
Analyzing changes in the complexity of climate in the last four decades using MERRA-2 radiation data — Nature Scientific Reports, 2020; Delgado-Bonal et al.
This extremely technical NASA paper looks at 4 decades of cloud data, suggesting that clouds are a key driver of climate, because a tiny increase in cloud cover can have a huge cooling effect. “Our research supports the idea that clouds and albedo, which ultimately determine the SW radiation, are variables of the utmost importance for current climate change, in agreement with previous research about the changes in stratocumulus or energy imbalance in the last four decades for example. An increase in cloud coverage of 0.1 would, on average, lead to a 7% increase in spectrally integrated global average reflectance of shortwave radiation.”
Decoupling CO2 from Climate Change — International Journal of Geosciences, 2024; Nelson & Nelson
“The world cloud cover has gone down 4.1% from 1982 to 2018. Calculations show that this could be responsible for 2.4°F of the 2.7°F. The research shows that most of the recent increase in temperature (89.9%) is because of fewer clouds.”
Atmospheric ionization and cloud radiative forcing — Scientific Reports, 2021; Svensmark et al.
“If changes in atmospheric ionization have a substantial impact on clouds, one would expect to observe significant responses in Earth’s energy budget. Here it is shown that the average of the five strongest week-long decreases in atmospheric ionization coincides with changes in the average net radiative balance of 1.7 W/m2 (median value: 1.2 W/m2) using CERES satellite observations.” — This exciting paper shows that the solar cycle can indeed have a large influence on temperature by the modulation of cosmic rays that nucleate clouds, leading to less albedo during peak sunspot times and more albedo during sunspot minima.
The changing nature of Earth's reflected sunlight — Proceedings of the Royal Society, 2022; Stephens et al.
This paper claims that recent warming is from slightly reduced albedo, not greenhouse forcing: “As in other recent studies, we find that by far the largest contribution to the increasing rate of change of earth’s energy imbalance is from an increase in net absorption of solar energy by the planet that has occurred over the past two decades due to reductions in the amount of solar radiation reflected to space by Earth. We cannot say if these changes in reflected sunlight are unprecedented given they are small within the context of the historical changes that must have occurred over Earth's history. Although small in that context, the changes are both statistically significant at the 95% confidence level and profound.”
Radiative Energy Flux Variation from 2001–2020 — Atmospheres, 2021; Dubal & Vahrenholt
This recent paper uses CERES data to show that a) the total amount of energy leaving the earth system has been INCREASING, and b) the total amount of shortwave radiation has been DECREASING. This is the OPPOSITE of what the CO2 hypothesis would predict.
Measurement of the Earth Radiation Budget at the Top of the Atmosphere—A Review — Remote Sensing, 2017; Dewitte & Clerbaux
“We highlight the link between long-term changes of the Outgoing Longwave Radiation, the strengthening of El Nino in the period 1985–1997 and the strengthening of La Nina in the period 2000–2009.”
Surface Albedo Feedback, Seasonal Heat Storage and Meridional Heat Transport Determine the Seasonality of Recent Warming in Antarctica — JGR Atmospheres, 2024; Haijin Dai
“1) Local radiative feedback and remote forcing warm the polar region of Southern Hemisphere, although additional energy is stored in the ocean. 2) Seasonal warming in Antarctica is mainly determined by anomalies in solar radiation, seasonal heat storage and meridional heat transport. 3) Stronger (weaker) eddy activity increases (decreases) poleward meridional heat transport and warms (cools) Antarctica in most months (June)”
Earth's Albedo 1998–2017 as Measured From Earthshine — Geophysical Research Letters, 2021; Goode et al.
“We measure a gradual, but climatologically significant 0.5 decline in the global albedo over the two decades of data. We found no correlation between the changes in the terrestrial albedo and measures of solar activity. The inter-annual pattern of earthshine fluctuations are in good agreement with those measured by CERES (data began in 2001) even though the satellite observations are sensitive to retroflected light while earthshine is sensitive to wide-angle reflectivity. The CERES decline is about twice that of earthshine.”