Summary of David Siegel: A framework for understanding climate | Tom Nelson Pod #239

00:00:00 - 00:55:00

In the "David Siegel: A framework for understanding climate | Tom Nelson Pod #239" YouTube video, David Siegel discusses his research on climate science and challenges the radiative model's accuracy in representing the real world. He explains that the Earth's climate system can be understood through a thermal model that focuses on heat and temperature gradients. Siegel also discusses the role of carbon dioxide (CO2) and water vapor in the greenhouse effect and the importance of ocean oscillations in climate systems. He emphasizes the need to consider natural factors, such as solar variation and ocean oscillations, as primary drivers of temperature trends. Siegel encourages critical thinking and offers a climate change course, Climate Curious , to help people make informed decisions. He also mentions scientists and papers that have influenced his thinking on climate and expresses skepticism towards predictions of upcoming solar minimums.

• 00:00:00 In this section of the podcast, host Tom Nelson interviews David Siegel about his recent research on climate science. Siegel explains that the Earth's climate system can be understood through either a radiative model or a thermal model. The radiative model focuses on the energy balance between incoming and outgoing radiation, but Siegel argues that it is an inaccurate representation of the real world. He explains that solar energy is converted to heat upon entering the Earth's system and is transported via four important gradients. The energy travels from the core of the Sun, where two hydrogen atoms fuse to create a large amount of energy, to the surface, where it is emitted as photons and travels to Earth. Only about 30% of the photons that reach the Earth's surface actually interact with the surface, with the rest being scattered by clouds or going back to space. In the radiative model, longwave photons are emitted when an object is heated by a shortwave photon, but only about 12% of these photons can escape to space unimpeded. The remaining photons can only interact with greenhouse gas molecules, which absorb the photon and vibrate at a higher energy state.
• 00:05:00 In this section of the YouTube video titled "David Siegel: A framework for understanding climate | Tom Nelson Pod #239", David Siegel discusses two possibilities for how carbon dioxide (CO2) contributes to the Earth's temperature. The first possibility is through mechanical energy transfer via collisions with air molecules, which increases the temperature through thermalization. The second possibility is through the radiative model, where CO2 molecules radiate longwave photons and the atmosphere heats up due to the increased residence time of the photons. However, Siegel explains that in reality, the longwave photon encounters a greenhouse gas molecule like CO2 before it radiates a photon away, and the collision with an air molecule usually happens first, increasing the speed of the air molecules and causing warmer air to rise. He also notes that CO2 does significant work ejecting thermal energy out to space. Siegel then uses real data from satellite measurements to demonstrate the greenhouse effect, showing that during the summer, about 100 watts per square meter comes from water vapor and another 100 from CO2, while during the winter in Antarctica, almost all the radiation is from CO2 due to the extreme dryness and lower temperature. The greenhouse effect is lower in Antarctica than in the Arctic due to its colder temperature and less atmosphere.
• 00:10:00 In this section of the YouTube video titled "David Siegel: A framework for understanding climate | Tom Nelson Pod #239", David Siegel discusses the role of carbon dioxide (CO2) and water vapor in the greenhouse effect, specifically in desert and tropical environments. He explains that CO2 is responsible for overnight temperatures in desert areas due to its downwelling radiation under clear skies. In contrast, water vapor plays a significant role in the greenhouse effect in the rainforest, where it keeps temperatures high during the day and releases energy at night, making cloudy nights warmer than clear ones. Siegel also explains that water vapor covers the same wavelengths as CO2 and covers most of the greenhouse effect on the oceans, with the North Pole being an exception due to its lack of water vapor. He concludes that, on average worldwide at sea level, about 100 watts per square meter of the greenhouse effect comes from CO2, as it constantly feeds energy into the air column and can absorb and transfer energy mechanically to the atmosphere.
• 00:15:00 In this section of the YouTube video titled "David Siegel: A framework for understanding climate | Tom Nelson Pod #239", David Siegel discusses the role of CO2 in the climate system and introduces the thermal model to explain how the Earth's climate system actually works. He explains that CO2 is not saturated as some believe but has a huge capacity to thermalize longwave radiation. The conversation then shifts to the thermal model, which focuses on heat instead of radiation. According to Siegel, heat always moves from hot to cold, and the Earth's climate system is driven by various temperature gradients. He discusses the vertical lapse rate, rotational gradient, and meridional temperature gradient. The thermal model suggests that the Earth's surface and air are hottest around 5:00 p.m. due to the build-up of heat during the afternoon, not because of peak radiation. The meridional temperature gradient shows that the tropics absorb two-thirds of the energy coming from the sun, and the oceans absorb and transport energy from the tropics to the poles. The thermal model is a more accurate representation of the Earth's climate system than the radiative model, which focuses solely on radiation.
• 00:20:00 In this section of the YouTube video titled "David Siegel: A framework for understanding climate | Tom Nelson Pod #239", David Siegel discusses the Earth's climate and the temperature gradients that drive it. He explains that melting ice is part of the annual conveyor belt, transporting excess heat from the tropics to the poles. The Earth's climate is determined by the meridional temperature gradient, which is influenced by the Earth's position relative to the sun and the shape of the continents. The diagram from Jav Vos's book shows the energy distribution by latitude, with a heat surplus inside the Tropics and a net loss of heat at the poles. About 20% of the energy coming into the oceans is transported away from the tropics to the poles, and the Earth can be out of radiative balance as excess heat goes down into the oceans and stays there for hundreds of years before coming back out. This is part of the global ocean conveyor belt, which connects four of the world's five oceans in a current driven by temperature and salinity.
• 00:25:00 In this section of the YouTube video titled "David Siegel: A framework for understanding climate | Tom Nelson Pod #239", David Siegel discusses the importance of ocean oscillations in climate systems, using data from Javier Venus' slides. The Atlantic Multi-Decadal Oscillation (AMO) and Pacific Decadal Oscillation (PDO) play significant roles in temperature trends, with the AMO set to turn negative in a few years. The mainstream temperature series that attempt to show how CO2 drives temperature appear to show a hockey stick pattern, but the fit with the AMO and PDO is much better than with CO2. The data from rural stations, which haven't been compromised by civilization, shows hotter temperatures in the past and milder temperatures in the last few decades. The Sunspot Cycles, which drive more or less energy into the oceans, are the primary drivers of temperature trends on the order of hundreds and thousands of years. The next double low point of the Sunspot model is predicted to be around the year 2450, and even if CO2 levels are high, temperatures may still be low due to this cycle. Siegel presents eight questions for those who use the radiative model to explain climate, including why the Earth's temperature is highest in July when it's farthest from the Sun and why more heat is escaping to space as temperatures rise. He suggests that clouds and ocean oscillations may be contributing factors.
• 00:30:00 In this section of the YouTube video titled "David Siegel: A framework for understanding climate | Tom Nelson Pod #239", David Siegel discusses various factors contributing to ocean warming and the lack of heating in Antarctica. He mentions several events such as decreased positive phase of the Atlantic Meridional Overturning Circulation (AMO), the peak of solar cycle number 25, a change in ship fuel type, and a huge underwater volcano eruption that have increased the greenhouse effect in the stratosphere and caused surface warming. However, these effects are natural and not man-made. Regarding ocean temperature, Siegel states that any numbers before 2004 are "garbage" due to the lack of mid-level ocean temperature measurements before that year. He also explains that CO2 cannot warm the oceans and that the only explanation for the observed rise in ocean heat is more direct sunlight penetrating the water and fewer clouds. When it comes to Antarctica, Siegel points out that it is the driest place on Earth, and the signal from CO2 should be very clear there. However, temperatures at the Vostok and South Pole stations are not moving with CO2 levels. He also mentions that Antarctica experienced a sudden stratospheric warming event this year, which is a natural phenomenon that has been happening for millions of years. Siegel also discusses the inconsistency between climate model simulations that include anthropogenic forcing and observed temperature trends, suggesting that natural variability overwhelms the forced response in the observations. He also explains that tropical temperatures are stable and insensitive to changes in CO2 levels. Finally, Siegel answers a question about why water vapor, the main greenhouse gas, is not being addressed in the IPCC reports or why there are no billions of dollars available for entrepreneurs to suck water vapor out of the atmosphere. He states that it's not about climate and never was about climate.
• 00:35:00 In this section of the YouTube video titled "David Siegel: A framework for understanding climate | Tom Nelson Pod #239", David Siegel discusses different mental models for understanding climate change and makes predictions based on these models. According to Siegel, if one uses a radiative model, the Earth is predicted to cook over the next 200 years due to the continued increase in CO2 emissions. However, if one uses a thermal model, solar variation and ocean oscillations are believed to be the primary drivers of temperature. Siegel predicts that temperatures will continue to rise for another 50 years and then start to descend. He also mentions the importance of studying heat and heat transport via temperature gradients. Siegel recommends the works of Andy May and Javier Venas for those interested in learning more about climate and critical thinking. He also announces a free webinar on critical thinking and a climate class starting in September.
• 00:40:00 In this section of the YouTube video titled "David Siegel: A framework for understanding climate | Tom Nelson Pod #239," David Siegel discusses his online climate change course, Climate Curious, which includes pre-recorded lectures, weekly live sessions, and a mobile app. He emphasizes that his goal is not to convince those who believe the Earth is dying due to human actions, but rather to reach out to "lukewarmers" who think there is a small dose response to adding CO2 to the climate. Siegel, who is a member of the CO2 Coalition, argues that humans have no control over the Earth's climate system and that more CO2 would be beneficial. He encourages lukewarmers to reconsider their assumptions and join the "absolute denial Camp" if they believe CO2 has no effect on temperature. The course aims to inform people and help them make better decisions.
• 00:45:00 In this section of the podcast, David Siegel discusses the various scientists and papers that have influenced his thinking on climate. He mentions Dick Linden and Will Hopper, as well as Tom Schula, whose work on thermalization he found intriguing but disagrees with. Siegel also emphasizes the chaotic nature of climate patterns, with some factors like orbital cycles and solar activity being predictable, while others like El Niño and volcanic activity are not. He mentions the role of cosmic rays and plate tectonics in shaping climate, and expresses skepticism towards predictions of upcoming solar minimums.
• 00:50:00 In this section of the YouTube video titled "David Siegel: A framework for understanding climate | Tom Nelson Pod #239," David Siegel discusses his perspective on climate patterns and the role of natural cycles in shaping temperature trends. He mentions the importance of understanding pressure systems, local conditions, and the impact of solar radiation on climate. Siegel also expresses skepticism towards the idea that CO2 emissions are the primary driver of ocean warming and argues that there will be slight warming and cooling periods between now and 2400, with greater variability the farther out in time one looks. He also predicts that the Earth will experience significant cooling within the next 1500 years, and that future generations will need to find ways to mitigate this trend. Siegel's views are influenced by the Milankovitch cycles, specifically the obliquity cycle, which he believes will determine the Earth's climate over the next few thousand years. He also mentions the work of climate researchers like Jim Steele and Roy Spencer and encourages listeners to explore their perspectives on climate science.
• 00:55:00 In this section of the podcast, David Siegel concludes his discussion on climate change by acknowledging the challenge of changing the beliefs of those who deny the role of CO2 in climate change through scientific evidence. He emphasizes that his upcoming class is for personal enlightenment only and not intended to convince others. Siegel encourages those interested in the topic to take the class and engage in the challenge of understanding climate change with rigor and data. He then concludes the podcast and signs off.