Last night, I gave a "Science Café" public talk about global warming and climate change and stuff like that (in Czech) which was substantially longer than any previous presentation of mine about the topic – it was something like two hours plus a discussion.



One may talk about lots of the sociology and history of the movement and it's interesting – and often infuriating. But I still think it's more relevant to focus on the hard science and the physical basis of all the phenomena.









Some of the comments I made aren't found on the slides – my audible statements during any talk never quite agree with what is written on the slides. I think it's a virtue – it allows the audiences to gain a multi-dimensional perspective and/or a more detailed information if you listen and read the slides.









Here is collection of topics that I covered and that you may want to cover in similar talks:



Why it is relevant for a physicist to talk about an interdisciplinary "applied" field such as climatology

Weather: observables, synoptic maps

Climate and weather: the difference and why the timescale 30 years is just a convention

Example: Weather today in Pilsen and what the climate predicts (high, low, average, how they differ throughout the year, warmest and coolest weather stations in Czechia)

How the temperature changes at nights and during days, how quickly the Earth would cool down if the Sun disappeared

Seasons and the tilted axis

The need of averaging to get the quasi-monotonically increasing curves: averaging over days, dates, and locations is needed, otherwise everything is noise

Once you suppress the noise, the variations of the averaged temperature are modest, comparable to variations of the human body's temperature; stretching the graphs in the vertical direction is how things are made "look dramatic" although they aren't

Global mean temperature 1850-2018: the warming episodes 1900-1945 and 1975-2018 are similar, despite quadrupled emissions

Satellite record, 1.3 °C/century trend, El Niño 1997/1998 in the middle

Hiatus 1997-2015: warming isn't reliable and persistent, the "noise" is too big

Global warming temperature isn't the best quantity: pole-to-equator difference changed from 20 °C to 60 °C, the global mean temperature just in a smaller interval between 6 °C and 14 °C; differences drive processes in the atmosphere

Timescales and drivers of temperature: galactic spiral arms and the 140-million-year periodicity

Continental drift (including explanation and comments about the flawed anti-Wegener group think): Antarctica mostly warm in recent 100 million years

Ice ages: graphs of temperature, CO2, CH4 in 650,000 years

Milanković's theory: tilt and eccentricity oscillate

June irradiation near the Arctic circle varies, the ice sheets over there respond, the Earth's albedo and temperature follows

Gerard Roe-style fix: derivative needed to Milanković functional relations, perfect agreement

Graphs are obtained from sediments or ice cores (Vostok pictures, comparison of ice core and annual rings)

Correlation of CO2 and temperature: temperature is the cause: outgassing explained

CO2 can't be the cause: there'd be no explanation for CO2-CH4 agreement

CO2 can't be cause: 100 ppm would have to warm planet by 8 °C but we recently added 120 ppm and warming was just 0.8 °C

CO2 isn't the cause: the 800-year delay

The greenhouse effect: 1824 Fourier, 1896 Arrhenius – a wrong explanation of ice ages

The greenhouse effect: how it resembles the greenhouse or the quilt and how it differs

Layers of the atmosphere, growth and decrease of temperature

Energy fluxes in the atmosphere, analogy with trade between countries, balanced account balances

Energy fluxes: 1366/4 = 342 W/m2; the denominator is \(4\pi r^2/\pi r^2 = 4\), why

Composition of atmosphere: nitrogen, oxygen not greenhouse gases

Three-atomic molecules needed, H2O main greenhouse gas, 30 °C, what it means

CO2 is the second, 3-5 °C in total, including around 1 °C of man-made so far

Negligible other greenhouse gases, infrared absorption spectra

Wrong fingerprint of the greenhouse effect: 10 km above equator should warm most quickly, is observed not to

Climate sensitivity as warming from CO2 doubling

CO2 concentrations: ppm(v) as a unit, 180 ppm in ice ages, why plants die near 150 ppm, 280 ppm interglacials, 405 ppm today, 2 ppm growth, 560 ppm in 2080, 700 ppm in room, 6,000-10,000 ppm in distant past, 10,000-50,000 ppm people faint, 40,000 ppm what we breathe out; 20% increase of agriculture from 40% increase of CO2, reducing CO2 to 280 ppm overnight is Stalin on steroids

Arguments that the sensitivity is near 1-1.5 °C

Higher climate sensitivities in the literature and why these values reflect societal pressures

Logarithmic dependence of the greenhouse effect, painting analogy, decreasing problem

Positive and negative feedbacks, examples, biased treatment by the IPCC

Climate models: predict 3 °C per century, what is seen is 1-1.5 °C century, no one fixes the discrepancy by picking the more accurate ones because climate models aren't treated as tools of science

Additional drivers: volcanos, Mt Piñatubo, 0.5 °C cooling for five years, volcanos emit just 2% of CO2 per year than humans do, eruptions could have been more frequent – cooler weather

Oceans: 2/3 of surface, absorb 1/2 of excess heat, 1/2 of new CO2 (4 ppm of emissions vs 2 ppm/year rise)

Oceans, cycles: PDO and correlation with the warming/no-warming epochs since 1850

Oceans: El Niño, La Niña, definitions, (existence of) local meteorological effects, effect on global mean temperature after a 6-month delay

Global conveyor belt and the 1,500-year periodicity

Solar activity: introduction to sunspots and magnetic fields, solar cycles

Maunder minimum and Little Ice Age; Dalton minimum, picture of frozen Thames

How it could work: cosmoclimatology, cosmic rays shielded by the Sun, but create cloud condensation nuclei, application to the spiral arm 140 million year periodicity

Combined predictions from several effects, uncertainties

Consequences of global warming: melting continental ice, sea was 120 meters lower 20,000 years ago

Oceans almost stopped rising 6-8 thousand years ago, rise of civilization

Sea level rise seems to be 30 cm/century now, was 2 meters some 10,000 years ago

Remaining ice – Himalayan and Alps glaciers, Greenland, Antarctica, how much sea level rise, why the latter can't melt

Trends of polar ice: Arctic was going down, Antarctic mostly up very slowly, comments on the biased reporting

Failure of predictions about ice-free summers, cheap ways to save polar bears

Impact on ecosystems: Pilsen-Prague temperature difference is 3 °C and is believed to be zero, Pilsen would "become" Prague, transfer of ecosystems would solve problems if any

Influence on extreme and undesirable events, droughts, torrential rains, wildfires, tropical cyclones – show graphs with non-existent trends (or "improving" trends whenever policies have affected those)

The 2005 hurricane season and how cataclysmic predictions about the "new normal" were made in 2005, how they turned out to be completely wrong

Actual effects that work: energy consumption per capita is correlated with GDP per capita very clearly, also with literacy rate, decreases infant mortality, children per mother – graphs

Summary: global warming panic has a scientific core, the greenhouse effect, that is taken out of the context, blown out of proportion, dozens of similar effects are overlooked, censored, and suppressed; most of the "secondary" alleged effects due to CO2 don't take place and aren't predicted by proper science

Summary: try to think, be critical