New research indicates the climate models that the Intergovernmental Panel on Climate Change (IPCC) relies upon for policymaking – and to claim humans are 100% responsible for the warming since 1850 – are fundamentally flawed. [some emphasis, links added]
The models cannot reproduce natural climate variability, nor can they simulate the positive water vapor and cloud feedback assumptions essential to demonstrably amplifying the warming thought to occur from doubling CO2.
The assumptions about total solar irradiance (TSI) and/or solar impacts on cloud formation and cosmic rays, which the IPCC chooses to emphasize, may underestimate the role of solar forcing in climate change fivefold.
Key points in Dr. Scafetta’s research summary include:
■ Equilibrium Climate Sensitivity (ECS) estimates for doubled CO2 (280 to 560 ppm) plus feedbacks may be 1°C (0.7°C to 1.3°C) due to the lack of positive feedback from water vapor and clouds.
■ The climate may be 4 to 6 times more sensitive to solar forcing factors (not just TSI alone) than presumed by models of radiative forcing.
■ Human activity may only explain about 30% of the global warming since 1850, with warm biases in the land surface record explaining 20% and natural solar-induced variability factors explaining 50%.
■ Variations in cloud albedo from 1983 to 2010 may explain 0.4°C of the global warming during this period.
Read more at the No Tricks Zone
none of the warmings since 1975 was caused by solar forcing
because top of the atmosphere tsi measured by NASA satellites
slightly declined since the 1970’s
climate models do significantly underestimate the daytime warming effects of the decline of air pollution since 1980. but that is a man made cause of global warming not natural
the decline in the percentage of cloudiness also contributes to daytime warming
it is not known if that is a natural climate forcing or a climate feedback to man-made causes of warming
the claimed warming of 0.3 to 0.4° C between 1850 and 1975 is just a wild guess
because the margins of error of the surface measurements in the 1800s are likely larger than the alleged change in temperature
with no feedbacks the effect of CO2 in the lab is +1° C per CO 2 * 2
there has been an increase in absolute humidity as the atmosphere warmed up after 1980
but there are no accurate measurements of the global average absolute humidity
+1.0 to +1.5 C. per CO2 x 2 is a reasonable guess for what we know right now
the average consensus guess of +3.0 per CO2 x 2 (since 1979) is not supported by the absolute humidity data we have … not to mention several other climate feedbacks we know even less
about
there is little evidence that the warming since 1975 had natural causes
and if the reduction in the percentage of cloudiness is not a natural cause of warming then there is almost no evidence of natural causes of warming since 1975
there was manmade cooling from air pollution between 1940 and 1975 and then manmade warming from the reduction of air pollution after the 1970s
CO2 emissions always cause global warming but not much between 1940 and 1975 because CO2 only increased 6.5% in that period, mainly offset by the increase of air pollution blocking sunlight. compared with the 25.8% increase between 1975 and 2025. amplified by the reduction of air pollution (blocking less sunlight in that period)
i called climate models “climate confuser games” because they’re just a bunch of wild guesses on the future climate and nobody really knows the right answer