 This talk is not so much research-oriented as observation-oriented, basically a collection of news articles, many of them from the New York Times, that over the last month I've been looking at and putting this together, searched up again, and quoted from a bit. So let's start out with a little background. So Earth receives about 340.2 watts per meter squared in solar radiation, and it reflects back about 100 watts per meter squared of that. So we're left with Earth absorbing about 240 watts per meter squared. Now if we look at the temperature of black body would be at to radiate 240.2 watts per meter squared out to space. We get a temperature of 255 Kelvin or minus 18 degrees C. Our civilization and history has not been at an average global temperature of minus 18 degrees C. It's been at an average temperature of plus 15 degrees C. And that's due to natural concentrations of greenhouse gases. So the greenhouse effect and an effect of global warming isn't anything new, isn't anything that we haven't developed our institutions and infrastructure at all along. So the Earth's surface temperature and the tropospheric temperature where the Earth radiates the space are tied together by confection. So you can't change one without changing the other. And the World Meteorological Organization has a list, an average lapse rate that's the temperature decrease with altitude of six and a half degrees centigrade per kilometer or about 3.56 degrees Fahrenheit per thousand feet. So when we increase greenhouse gases, we increase the opacity of the atmosphere, the inability to just transmit something through the atmosphere. And that pushes the emissions to space to higher altitudes. And it's because of the lapse rate, it's colder at higher altitudes. And colder means less radiation emitted. So there you have why there's a greenhouse effect in a nutshell, doesn't take a huge model to understand it. And in fact, a calculation was first done in about 1967 that was fairly accurate. So a bit of back of the envelope consideration, things they sort of play with. If we look at the average temperature, the surface temperature of the Earth is 288 Kelvin and subtract the effective radiation temperature, we get 33K. And it'll lapse rate of 6.5 degrees per kilometer. That's an effective emission altitude of just over five kilometers above the surface. More detailed radiative calculations indicate that doubling the concentration of CO2, carbon dioxide, would reduce the infrared leaving the troposphere by four watts per meter squared. And just looking at how a black body would handle that, it corresponds to a temperature of emission lower by about 1 degree C or higher by about 0.165 kilometer in altitude using the lapse rate. And if we bring that down to the surface using the lapse rate, we get about a degree of heating. But that degree of heating causes the water vapor to increase. And back in 1967, Sukhiro Manabe and Richard Weatherold estimated that the net effect would be a heating, surface heating of about 2.5 degrees centigrade or 2.4 degrees centigrade. Now, just this last month, Berkeley Earth released collections of measurements and statistical analysis that depict the warming over time. And Zeke Housefather wrote an opinion in the New York Times indicating that the warming seems to be accelerating, not just staying at the same rate. And, you know, that's depicted in the graph here in this red dot region, this being 2023 to date. Now, this year, sorry, June, July, August and September were all the hottest on record since the mid-1800s when reliable measurements first started. And the warming through 2022 compared to pre-industrial has been about 1.3 degrees centigrade or 2.3 degrees Fahrenheit. And these temperatures just wouldn't have occurred without the global warming. And a quote by Zeke Housefather from Berkeley Earth. Now, Berkeley Earth has had an interesting start. It was founded by the Millers, I think, Roger Miller is a physicist at UC Berkeley. And partly to evaluate skeptics consideration, like it's all due to a heat island or a data bias. And so they started, you know, thinking, well, maybe some of these skeptic considerations have merit. And what they found is none of them influenced the result significantly. So in that sense, Berkeley Earth irritated a number of atmospheric scientists because it was like the assumption was maybe these atmospheric scientists can't do it right. And what they got was pretty much agreement, but they at least were honest brokers in the sense that. They reported the results they got that basically matched what atmospheric scientists were already doing. Now, one of the observation is that tropical storms are intensifying much more rapidly. For instance, Otis, which just recently hit Acapulco, became a category five hurricane from a tropical storm in 24 hours. And one of the people whose name I recognize, you know, from decades of research on clouds and storms was Kerry Emanuel, who said, you know, the worst nightmare used to be that you went to bed with the storm. 36 hours from land fall, that was a tropical storm, and you woke up and it was a category four hurricane and 12 hours left to evacuate people. And what actually happened with Otis was you woke up and it was a category five hurricane where it had been a tropical storm before. And it was only a few hours from landfall and there just simply wasn't time to evacuate people. Another observation is that summer heat has become more extreme and you can see a distribution in 1963 up here at the top and one in 2023 down here at the bottom and the change over time. So while the global annual average temperature has changed only by about 1.3 degrees, there have been significant changes in extreme weather. And Phoenix had sort of the summer from hell in that they had 31 days in a row that were above 110 degrees Fahrenheit. And one of the articles I read mentioned that Tempe, Arizona, which is just outside of Phoenix, people had shifted to nighttime activities, both, I mean, the only time you could be outside, whether you were a repairman or just enjoying outside is at night. So we have drought, heat, and wildfires. The top picture here is from the Canadian wildfires, which a lot of the US became familiar with through the smoke. Alberta had almost a million acres burned and 30,000 residents had to evacuate. And they declared an emergency with 110 wildfires burning across the province. And those fires produce a smoke with a lot of particles smaller than 2.5 microns, which are a danger to breathe. The middle picture was the Doyle fire in California. And this is what I think of whenever I hear the word firestorm, because this truly is a firestorm. Back in 1989, with friends had been up at Point Rays, California, and about the middle of the day, we looked back to the south and there was all this smoky haze and we thought, well, what's going on? And that night driving back, it was eerie looking up at the Oakland Hills fire and there was this, you know, licks of flame and an orange glow. It's something you don't forget. And in California, the wildfires have burned parts of the Pacific Crest Trail. And the Dixie fire was the first ever to cross the crest of the Sierra Nevada. So when people are hiking now, there's these stretches like in this bottom picture that are denuded. And so there's a lot more sunlight and a lot more chances for dehydration, along with weirder weather, bone dry soil, and most of all, the increasing threat of wildfires as you're hiking. And this is turning out to be an El Nino year. In El Nino years, the east to west trade winds basically subside and the water in the southeastern Pacific off of Peru becomes warmer, fewer nutrients, so fishing isn't as good in the inverse. Oh, and then in the El Nino year, because of the heat in the ocean, the average temperature of the earth tends to be higher. In El Nino year, the trade winds are stronger. It blows the warm water, surface water to the west where it kind of stacks up. This is one of those things where, you know, sea surface is not uniform. If you have wind stacking up water, you know, you have a higher sea surface. You also have evaporation increasing salinity. So you get a hailing gravity circulation and cold water rises up off the coast of Peru with more nutrients and some more fish. So now also places that like in Vermont have flooded that aren't anywhere near a river that fills up and overflows. It's a bank. So you can have flooding apart from rivers just because of the amount of rain and lack of drainage and rising temperatures mean the atmosphere can hold more water vapor. So you can have more rainfall and it's getting harder to adapt to changing conditions because it's just everywhere. And many places that aren't in the federal flood pangs, there are 16 million properties are at risk compared with 7.5 million in federally designated flood zones. And the storm gets worse places like New Orleans, Miami, Houston, Charleston, or even areas of New York City. Can use up the budget for climate resilience without solving anyone's problems permanently. That's one thing I didn't look at is disease spread. One of the increasing problems is the US is using up its aquifers at a high rate and some of them are starting to run dry. And as you pump water out of an aquifer without replacing the water, the aquifer can collapse. So it becomes an irreversible loss of groundwater that supplies many of the nation's water systems. So there are going to be areas that we've populated that aren't going to have sufficient water. Now, another thing that's been observed is that the ice sheets in West Antarctica are melting due to water that's warm underneath them, warming water underneath them, melting the ice. So those are thinning and the mass of those is basically restrained glaciers on land from shoving ice into the sea. So as those thin, there's likely to be an increase in glacier ice in Antarctica moving into the sea and raising sea level. And recent research appears that we have lost control of the West Antarctic ice sheet and that even if emissions are limited at this point, they're still going to keep thinning. So we are going to see some sea level rise from that. And right, Phil, we are past the point of no return. As we are on the aquifers, well, a matter of how high the sea level will rise, which isn't necessarily uniform at all. So there's a consequence to that. Insurance companies are realists. And if they're facing growing losses, they're going and are pulling out of places that they can't avoid having those losses, like California, Florida and Louisiana. And since most banks typically require insurance when writing a mortgage, if you can't get insurance, then that affects the real estate market and the whole economics of the area. And just on the 1st of November, the Senate Budget Committee sent letters to 40 insurance companies seeking documents that show where in the country they're pulling out and where they're planning to pull out of. And basically it's the increase in drought, wildfires and extreme weather that is making places uninsurable. We don't have so much desk grains that scatter the light. It's sulfate like Mount Pinatubo blew tons of sulfate into the stratosphere where it had about a 13 month half life. On the other hand, Mount St. Helens mostly just erupted ash, which fell out more quickly and didn't really affect the sunlight that much. Now looking at an article in The Economist, they're talking about a populist backlash against climate mitigation policies. Basically, if it costs money or causes an uncomfortable transition, there's a significant number of people and policy makers that don't want to go there. The Economist notes that eventually technology will eliminate much of the reason for this, that clean energy is already cheaper than dirty in many parts. But it also depends, like in Africa, on interest rates. If you have a 15% interest, wind and solar are not cheaper than fossil fuels for generating electricity, but at 7% or 8% interest they are. And then the graph on the right hand side shows the spread between right wing and left wing opinions on whether climate is a major problem. It's notable that the United States has about the biggest spread. And that's what I have for today. So we're not living in the climate that, certainly not that our grandparents did, and not even that many of us grew up with. Some of the articles we're talking about, you know, we used to go out and just sit on the lawn chairs and enjoy the summer and we can't do that anymore. It's been too hot. And even a few years ago, I was reading that in Rochester, New York, that backyard winter ice rinks were becoming unfeasible. It just wasn't cold enough, enough days in the winter to maintain the ice. There are geoengineering ideas like, you know, putting aerosols into the upper atmosphere, like Mount Pinatubo did, reflecting more sunlight, but that doesn't get you back to zero effect. You've reduced or you've improved the energy balance by reflecting more sunlight, but that doesn't mean you get the same circulation patterns because it's handled differently. One thing you don't want to do is anything that would have a chain effect of reducing greenhouse gases to zero because if you did that, the atmosphere would gradually lose all its water vapor over about 50 years because the non-precipital greenhouse gases, meaning carbon dioxide and methane, act as a rheostat for the amount of water vapor in the atmosphere. Andy Laces and colleagues did a study on that with what happens if you removed all the non-precipitating, meaning not water vapor, but all the other greenhouse gases from the atmosphere in about 50 years, there were still non-ice covered oceans in the tropics, but the ice had extended in the oceans much further south and the atmosphere basically had gradually lost all its water vapor. Water vapor is a strong greenhouse gas. It means that if you double carbon dioxide, it creates about a one degree change in surface temperature, whereas the water feedback effect adds another degree and a half, at least according to that early estimate by Minami and Weatherhold, but it's controlled by the amount of CO2 and methane. Yeah, greenhouse gases raise the temperature and the amount of water vapor the atmosphere can hold is temperature dependent, highly temperature dependent. So you get more rain and warmer oceans mean there's more energy for severe storm development. Thank you.