https://www.mdpi.com/2225-1154/13/3/43
*Authors* Alec Feinberg https://doi.org/10.3390/cli13030043 *Published: 21 February 2025* *Simple Summary* Global warming (GW) occurs when we add greenhouse gasses (GHGs) like CO2 and darken the Earth with black roads and roofs. This is called “forcing” in climatology. Warming due to forcing is increased by nature’s feedback problems like snow and ice melting which makes the planet hotter as we lose reflectivity. But as the planet loses reflectivity and warms, more snow and ice melt, and this is called a feedback loop. Most of the feedback and feedback loop problems are due to atmospheric water vapor, which is increasing as the planet becomes hotter. This is because warmer air holds more water vapor. More water vapor in the atmosphere is a problem because water vapor is a strong GHG. This study estimates that water vapor GHG increase is 83% of the total feedback problem. In short, global warming is the sum of forcing and feedback problems. Most people are concerned about CO2 forcing problems from emissions (from cars, power plants, etc.). However, this study estimates that GW due to feedback in 2024 has become larger than forcing with about 54% due to feedback and 46% due to forcing. Although forcing causes feedback, it is unlikely that if we could remove all the forcing (CO2, etc.) that feedback would also fully reverse since we are over the 50% point. This adds to our global warming risks. This study estimates feedback trends over time with simple graphs which helps us better understand our global warming root causes. Calculations for these are based on simple data manipulation on how much faster global warming occurs, compared to energy consumption. This is shown to provide feedback estimates. Results show that, in 2024, forcing, what man does, like adding CO2, is now less of a problem than what nature’s feedback warming is doing, like adding water vapor and the snow and ice melting. Because GW due to feedback is larger now than forcing, this study highly recommends that we should try and mitigate feedback as well. There are two methods to mitigate global warming: reducing manmade GHGs (a secondary warming source) and/or using solar geoengineering (SG). SG is 62% more efficient than CO2 reduction as it uses methods to reduce the Sun’s energy (the primary warming source) absorbed by the Earth, to help cool it. For example, we could brighten our streets and roofs to reflect the sunlight away, to reduce the amount of heat absorbed. However, we will need stronger solar geoengineering methods, which likely will include ways to reflect sunlight away in the stratosphere and/or in outer space. GHG current mitigation methods are likely far too slow to keep up with the rate of aggressive feedback increases and CO2 lingers in the atmosphere for 100’s of years. Furthermore, GHG reduction efforts have been disappointing, with many obstacles other than emission problems, like wildfires, and lack of worldwide unification with the U.S. again pulling out of the Paris Agreement. Therefore, given the current circumstances including feasibility, it is unfortunate, but we should not expect that we can mitigate GW using only GHG reduction methods according to a risk assessment provided here. There are currently no strong SG efforts, which can take years to develop and implement. There are no guidelines in the Paris Agreement to stop even the opposite problem of worldwide abuse of dark roads, roofs, cars, and buildings, a form of negative SG. Candidates for SG besides urbanization include the Arctic and Antarctic to help cool the planet. In this paper, the method called annual SG, which can help stop yearly GW increases to stabilize temperature increase problems, is recommended while GHG reduction methods can improve. SG implementation will take years to develop and urgently requires the help of organizations like NASA, Space X, and the Canadian, Chinese, and European space agencies. *Abstract* This paper provides climate feedback trends, quantifies the feedback-doubling (FD) period, considers urbanization influences, and provides related equilibrium climate sensitivity (ECS) estimates using data from 1880 to 2024. Data modeling is accomplished by focusing on statistically significant stable normalized correlated rates (NCRs, i.e., normalized related slopes). Estimates indicate that the global warming NCR is increasing by a factor of 1.65 to 2.33 times faster than the energy consumption NCR, from 1975 to 2024. The reason is feedback amplification. This is supported by the fact that the NCR for forcing and energy consumption shows approximate equivalency in the period studied. Results provide feedback yearly trend estimates at the 95% confidence level that key results will fall within the IPCC AR6 likely range. The projected 2017–2024 feedback amplification estimates, using the EC approach, range from 2.0 to 2.16, respectively. A feedback amplification of 2.0 (approximately equal to −2.74 Wm−2 K−1) doubles the forcing, indicating that in 2024, more than half of global warming (53.7%) is likely due to feedback. Relative to the feedback-doubling (FD) threshold (i.e., the point where feedback exceeds forcing), the FD overage is 3.7% in 2024. This is the amount of feedback exceeding the forcing portion found to have a surprisingly aggressive 3.1% to 3.9% estimated overage growth rate per decade. We now ask, shouldn’t we try to mitigate feedback as well as GHG forcing, and if forcing could be removed, would global warming fully “self-mitigate”? Additionally, CO2 yearly increases are complex, with poor reduction progress. Therefore, this study’s risk assessment urgently recommends that supplementary “mild” annual solar geoengineering is necessary, to reduce the dominant aggressive feedback. SG reduces the primary solar warming source creating 62% higher mitigation efficiency than CDR. Urgency is enhanced since solar geoengineering must be timely and can take years to develop. This study also estimates that 75% to 90.5% (83% average) of the feedback problem is due to water vapor feedback (WVF). High WVF also plagues many cities needing local SG. Trend analysis indicates that by 2047, the earliest we may reach 10 billion people, feedback amplification could reach a value of 2.4 to 2.8. Furthermore, by 2082, the year estimated for 2× CO2, at the current rate, feedback amplification could range from 2.88 to 3.71. This yields an ECS range from 2.4 °C to 3.07 °C, in reasonable agreement with the reported estimated range in AR6. An overview of recent urbanization forcing attribution indicates the ECS value may be lower by 10.7% if this forcing is considered. For numerous reasons, the lack of albedo urbanization Earth brightening requirements in the Paris Agreement, is unsettling. In addition, a model assesses effective forced feedback (EFF) temperature characteristics of up to 1.9 °C, providing interesting feedback insights that may relate to high GW land and pipeline temperature estimates. Lastly in addition to urbanization, solar geoengineering in the Arctic and Antarctic is advised. Worldwide efforts in GHG mitigation, with no significant work in SG, appears highly misdirected. <https://www.mdpi.com/2225-1154/13/3/43#> <https://pub.mdpi-res.com/climate/climate-13-00043/article_deploy/html/images/climate-13-00043-ag.png?1740457641> Graphical Abstract *Source: MDPI* -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/geoengineering/CAHJsh9960dkfq2cmqZfWFL4qDgEBvye-a9rZfKZT1%3DnxkYOq9Q%40mail.gmail.com.
