How much has the Sun influenced Northern Hemisphere temperature trends? An ongoing debate

Abstract

To evaluate the role of Total Solar Irradiance (TSI) on Northern Hemisphere (NH) surface air temperature trends it is important to have reliable estimates of both quantities. 16 different TSI estimates were compiled from the literature. 1/2 of these estimates are low variability and 1/2 are high variability. 5 largely-independent methods for estimating NH temperature trends were evaluated using: 1) only rural weather stations; 2) all available stations whether urban or rural (the standard approach); 3) only sea surface temperatures; 4) tree-ring temperature proxies; 5) glacier length temperature proxies. The standard estimates using urban as well as rural stations were anomalous as they implied a much greater warming in recent decades than the other estimates. This suggests urbanization bias might still be a problem in current global temperature datasets despite the conclusions of some earlier studies. Still, all 5 estimates confirm it is currently warmer than the late 19th century, i.e., there has been some global warming since 1850. For the 5 estimates of NH temperatures, the contribution from direct solar forcing for all 16 estimates of TSI was evaluated using simple linear least-squares fitting. The role of human activity in recent warming was then calculated by fitting the residuals to the UN IPCC's recommended anthropogenic forcings time series. For all 5 NH temperature series, different TSI estimates implied everything from recent global warming being mostly human-caused to it being mostly natural. It seems previous studies (including the most recent IPCC reports) that had prematurely concluded the former failed to adequately consider all the relevant estimates of TSI and/or to satisfactorily address the uncertainties still associated with NH temperature trend estimates. Several recommendations are provided on how future research could more satisfactorily resolve these issues.

arXiv comment71 pages, 18 figures. To be published in Research in Astronomy and Astrophysics

References in corpus (66)

• Revisiting the Sunspot Number
• Grand minima and maxima of solar activity: New observational constraints
• Low cloud properties influenced by cosmic rays
• Evolution of the solar irradiance during the Holocene
• A new approach to long-term reconstruction of the solar irradiance leads to large historical solar forcing
• The new Sunspot Number: assembling all corrections
• Cosmic Rays and Climate
• Empirical evidence for a celestial origin of the climate oscillations and its implications
• Patterns of photometric and chromospheric variation among Sun-like stars: A 20-year perspective
• Reconstruction of the Sunspot Group Number: the Backbone Method
• The Maunder minimum (1645--1715) was indeed a Grand minimum: A reassessment of multiple datasets
• A Revised Collection of Sunspot Group Numbers
• Magnitudes and Timescales of Total Solar Irradiance Variability
• Do We Know of Any Maunder Minimum Stars?
• The Mount Wilson Observatory S-index of the Sun
• Stellar Evidence that the Solar Dynamo may be in Transition
• Photometric Variability in Kepler Target Stars. III. Comparison with the Sun on Different Timescales
• Sun-as-a-Star Spectrum Variations 1974-2006
• The Sun is less active than other solar-like stars
• Methodology to create a new Total Solar Irradiance record: Making a composite out of multiple data records
• Multi-scale harmonic model for solar and climate cyclical variation throughout the Holocene based on Jupiter-Saturn tidal frequencies plus the 11-year solar dynamo cycle
• Does the Sun work as a nuclear fusion amplifier of planetary tidal forcing? A proposal for a physical mechanism based on the mass-luminosity relation
• The Impact of the Revised Sunspot Record on Solar Irradiance Reconstructions
• On-Orbit Degradation of Solar Instruments
• Are solar brightness variations faculae- or spot-dominated?
• Long Term Photometric Variability in Kepler Full Frame Images: Magnetic Cycles of Sun-Like Stars
• On the astronomical origin of the Hallstatt oscillation found in radiocarbon and climate records throughout the Holocene
• Empirical analysis of the solar contribution to global mean air surface temperature change
• Discussion on climate oscillations: CMIP5 general circulation models versus a semi empirical harmonic model based on astronomical cycles
• Evidence for photometric activity cycles in 3203 Kepler stars
• A shared frequency set between the historical mid-latitude aurora records and the global surface temperature
• On climate response to changes in the cosmic ray flux and radiative budget
• Response of Cloud Condensation Nuclei (> 50 nm) to changes in ion-nucleation
• Revised historical solar irradiance forcing
• Photospheric and chromospheric magnetic activity of seismic solar analogs. Observational inputs on the solar/stellar connection from Kepler and Hermes
• Evidence of nearby supernovae affecting life on Earth
• ACRIM total solar irradiance satellite composite validation versus TSI proxy models
• Synchronized helicity oscillations: a link between planetary tides and the solar cycle?
• The long sunspot cycle 23 predicts a significant temperature decrease in cycle 24
• A cosmic ray-climate link and cloud observations
• Why isn't the solar constant a constant?
• The Dimmest State of the Sun
• Discussion on the spectral coherence between planetary, solar and climate oscillations: a reply to some critiques
• Solar activity: intrinsic periodicities beyond 11 years
• Short-Term Orbital Forcing: A Quasi-Review and a Reappraisal of Realistic Boundary Conditions for Climate Modeling
• Correlation of Spectral Solar Irradiance with solar activity as measured by VIRGO
• Critical Analysis of a Hypothesis of the Planetary Tidal Influence on Solar Activity
• Power spectra of solar brightness variations at different inclinations
• No evidence for planetary influence on solar activity
• Activity-Brightness Correlations for the Sun and Sun-like Stars
• Phase coherence and phase jumps in the Schwabe cycle
• Global temperatures and sunspot numbers. Are they related? Yes, but non linearly. A reply to Gil-Alana et al. (2014)
• Transition from spot to faculae domination -- An alternate explanation for the dearth of intermediate \textit{Kepler} rotation periods
• Solar-type Stars Observed by LAMOST and Kepler
• On the contribution of quiet Sun magnetism to solar irradiance variations: Constraints on quiet Sun variability and grand minimum scenarios
• HD 4915: A Maunder Minimum Candidate
• Schwabe, Gleissberg, Suess-de Vries: Towards a consistent model of planetary synchronization of solar cycles
• Solar Resonant Diffusion Waves as a Driver of Terrestrial Climate Change
• The place of the Sun among the Sun-like stars
• Comment on the paper by Popova et al. "On a role of quadruple component of magnetic field in defining solar activity in grand cycles"
• Sun-like Stars Shed Light on Solar Climate Forcing
• The glacial cycles and cosmic rays
• The Little Ice Age was 1.0-1.5 °C cooler than current warm period according to LOD and NAO
• Interglacials, Milankovitch Cycles, and Carbon Dioxide
• Reply on Comment on "High resolution coherence analysis between planetary and climate oscillations" by S. Holm
• Dimming of the Mid-20th Century Sun

Cited by in corpus (7)

• Impacts and risks of "realistic" global warming projections for the 21st century
• Reply to "Comment on 'Advanced Testing of Low, Medium, and High ECS CMIP6 GCM Simulations Versus ERA5-T2m' by N. Scafetta (2022)" by Schmidt, Jones, and Kennedy (2023)
• Advanced testing of low, medium and high ECS CMIP6 GCM simulations versus ERA5-T2m
• CMIP6 GCM ensemble members versus global surface temperatures
• Triskels and Symmetries of Mean Global Sea-Level Pressure
• On the Nature and Origin of Atmospheric Annual and Semi-annual Oscillations
• Iterative construction of the optimal sunspot number series