The Limitations of Climate Change Models

>> Steven Koonin: Okay since this is a policy oriented gathering, I thought the best thing I could do as a scientist was to lay out some of the factual context for climate and the closely related subject of energy. So if you listen to most of the political dialogue and certainly the Media, what you hear is that climate science compels us to make large and rapid reductions in greenhouse gas emissions, take climate action immediately and on a large scale.

And that is driven by the fact that global greenhouse gas emissions have been rising at about 1.5% a year. The UN says that we need to get to net 0 emissions by 30 years from now in order to, quote, avoid the worst effects of climate change. And they have various trajectories of emissions going forward.

Do I have a pointer, by the way? I guess not. As you can see there, emissions would have to go to 0 by 2050 or so if we are to keep the global temperature rise to one and a half degrees above pre industrial.

>> Steven Koonin: You think about policy required to implement something like that, and they have to strike a balance.

On the one side, we've got the certainties and uncertainties of climate science. And I was amused to hear during the banking talk yesterday the reverence with which physics and chemistry are treated in terms of the precision and certainty of their understanding. It's very much not the case, and the hazards and the risks of a changing climate.

And on the other side, as we'll see, the world's growing demand for reliable, affordable and clean energy. Striking that balance is about policy, you have to fold in values and priorities, environment versus development, tolerance for risk, equity across north south, and across generations. And really, do any of the responses that you might make in policy make a difference?

And how much will they cost? And of course, it's in the center box that I expect most of you are interested and focused. So I wanna take you through some of the considerations involved in striking that balance in the form of three high level statements. The first is that the notion of a climate crisis, which you hear so often, has scant scientific support.

The climate today is not broken, and fears of future catastrophes depend on extreme emission scenarios that are fed into models that are entirely unsuited to the task. And so if we act too rapidly and in an ill thought through way, we will incur a greater threat to human well being than climate change itself.

And of course, I'm going to show you data and trends that support these statements. The second is that if you advocate for rapid or overly rapid global decarbonization, you've got a moral issue which I will try to elucidate. And the third is if you try to decarbonize too rapidly at the national level, it's gonna be disruptive, expensive and will ultimately degrade national security.

Let me start with a definition. First, weather is not climate. Climate is the long term average, typically 30 years of the properties of weather. And that's nicely illustrated by this chart, which shows about a 900 year long record of the annual height of the Nile river measured during the summer minimum in Cairo.

The Egyptians, of course cared a lot about the height of the Nile, as did the people who were ruling Egypt in any given time. And what you see when you look at this graph, the blue values are the annual values, is that there's a lot of up and down from year to year.

One year it could be up at almost 6 meters, and the next year or so it's down at 2 meters or 1 meter. So that's weather, it happens year to year. The second is if you look at the 30 year average, which is the red line, you can see that it also goes up and down a lot.

And if you were alive during the first 150 years of this record, you would see the annual minimum going down and down. And no doubt some medieval egyptian climate panel would be screaming new normal, new normal, and recommending prayers and sacrifice. In fact, the climate varies a lot on its own.

Human influencers were entirely absent during this time. And if they just waited a couple hundred years after 700, you see it comes back up quite a lot. So you can get fooled a lot by year to year variability or by variability over decades. And untangling the response to human influences from this natural variability of the climate system is something that is a major challenge in the science these days.

We do it a lot in the media. The media entirely misrepresent the science. Here's a little vignette, NASA press release in March of 2020. The Guardian newspaper in the UK in December 2019. Headline, Greenland's ice sheet is melting seven times faster than in the 1990s. And if you look in the text of the article, the rate of ice loss has risen from 33 billion tons a year in the 90s to 254 billion tons a year in the past decade.

That's a true statement, but if you look at it in context, it carries a very different message. Here's the actual data compiled by the Danish Meteorological Institute. This is how much Greenland lost in ice year by year, averaged over ten years. And you can see that from 1990 to 2012 or so, it did go up a lot.

So quite a part of this graph. But if you look at the past, almost 100 years, it went up and down a lot. And if you go back to 1930, when human influences were much smaller than they are today, about one fifth, you can see that it was goozed ice almost as much.

And even as the globe warmed from 1930 up to 2022, the ice loss went up. Up and down, and, in fact, is currently declining rather than going up. So, this is not global warming, okay, this is weather, turns out to be weather in the north Atlantic. So, it's impossible to talk about weather without talking about the unusual heat that we have seen this summer.

Here is context, okay, this is data from the US EPA, official government data. It's the heat wave index, we can talk about how you define heat waves, but not now. And you can see that in the last 40 years or so, from 1980, not much change. This does not include the last summer, of course, we don't have that data yet, but even so, one year is not gonna make all that much difference in our climate sense.

And it was a lot more active in terms of heat waves in the 1930s than it is now, when, again, human influence is much smaller. This is the satellite derived record of the global temperature, temperature of the lower atmosphere month by month, okay? And the last point in that graph is July 2023, last month, and you can see, wow, big spike, right?

But when you look at it, you see other big spikes, mostly due to El Ninos, and you can see that there's a gradual long-term trend. So, however much the media and other folks make of the unusually hot July that we have had, that's not human influences, it's weather.

The long-term trend in this data may well be human influences, but they can't resist capitalizing on dramatic weather events to make the point. There it is, what are the causes? Maybe greenhouse gases, but that seems unlikely again, cuz greenhouse gases act over long time periods smoothly. El Nino, we are in the beginnings of another El Nino cycle.

There are other oscillations in the climate system that are conspiring to work together. Stratospheric water vapor is another explanation. You may not know that in January of last year, there was an enormous underwater volcanic eruption that increased the water vapor in the upper atmosphere by 10 to 13%.

You can see it here in this graph, that big dark blob at the end of the graph, the most recent years, is the water vapor from this underground eruption, undersea eruption. And that increases the heat trapping of the atmosphere. And then finally, we've been cleaning up the lower atmosphere from coal emissions and from ship emissions that allows the earth to absorb a little more sunlight, and that's also playing a role in the recent warming.

Finally, urban heat island, you hear a lot about records being broken, Phoenix, Houston, and so on. The temperature in the cities is hotter than the surroundings by as much as 5 or 6 degrees. And if you've got a weather station that's in the middle of a city that's growing and growing and growing, the heating of the city starts to affect whether you're gonna break a record or not, all right?

Temperature is not the only thing that is a manifestation of climate. Of much greater concern are extreme weather events and sea level rise. This is a chart from the most recent UN report issued about a year ago. And the colors indicate whether a trend has been observed or not in various phenomena.

The ones associated with heat and cold, well, yeah, we've got more heat waves globally, though not in the US, less, fewer cold spells. But then there's a whole category of wet and dry for which there is no trend. There's a whole category of wind, including tropical cyclones, hurricanes, typhoons, again, for which there is no trend, etc.

So, in fact, for most of the extreme weather events, we have not seen trends over the last century. Here are some of the text that goes along with it. Low confidence in most reported long-term trends in hurricanes. Low confidence in mid latitude storms, tornadoes, hail, lightning, no trends, etc.

The one in which there is confidence is that we have seen some increase in heavy precipitation on a global scale over land. And you go on and on again, not a lot that gives us support that there is a climate crisis underway. Here's some of the data for hurricanes, this is the record of the number of hurricanes globally.

Upper trace is all tropical storms, lower trace are hurricanes, and this is a record that extends over 50 some odd years, it's hard to see any change at all. This is a measure of hurricane activity, it weights the strongest storms more than the weaker storms. Again, globally in the top, northern hemisphere on the bottom, lots of ups and downs over 50 years, but it's hard to find any effect.

And in fact, the official reports say we can't find any trends. I'm not gonna go through the language, but that's what it says. By the way, I don't know if you'll have access to the charts, but they have links to all of the supporting either UN reports or quality peer-reviewed literature in each of the statements.

So, that's the climate of today, in the past, you might ask, what about the future? Well, for that, we rely on models. And one of the major measures of a model is how sensitive is it to increasing the carbon dioxide? If you doubled the carbon dioxide in the model, by how much would the temperature go up?

And that's shown in this graph, there are about 40 different models listed there, they're produced by institutes and universities around the world. And what's plotted is how sensitive the model is. And the ones in yellow, about 40% of them, were deemed too sensitive by the UN and so are not used at all.

That's a little bit scary, the world's best modelers making their best tries get it wrong 40% of the time. It's even worse when you ask, how well do the models produce the temperature history that we've seen? And that's shown on these graphs, the black is the actual observed temperature rise of the globe and the different traces are the different models.

And you can see that many of the models differ from the data or that differ from themselves by more than the temperature rise that they're trying to describe. And in fact, even the climate modelers don't believe their own models, at least at the regional level. Tim Palmer at Oxford and Bjorn Stevens, who is the director of the Max Planck, Institute for Meteorology says for many key applications, the current generation of models is not fit for purpose.

There's Bjorn, he gave a lecture at UCLA about a year ago. And he says it's difficult, in many places impossible, to scientifically advise societal efforts to adapt in the face of unavoidable warming. We can't assess the extent to which a given degree of warming poses an existential threat.

And there's Tim Palmer. In an email not publicly published, but broadly published in the National Academy membership, he says our understanding of climate change, especially at the regional scale, is rather poor. How can a country adapt if it doesn't even know the sign of precipitation change, as the IPCC figures show?

And he says the policy and decision makers start to feel uncomfortable when we say that, they'd rather we didn't say such things in public, they claim it undermines the public's faith in the need to take action. And I think this is a disease, a dysfunction of the science in this particular field.

As a scientist, I think it's our duty to lay out the science knowns and unknowns transparently, completely, and without bias. That's not happening, I can tell you, show you specific examples. All right, let's look at just one or two more model projections, sea level. I live most of the time in Manhattan in New York City.

There's been a tide gauge at the foot of Manhattan, the southern tip, for 150 years, maybe a little more. This is the rate of rise of the sea at the tip of Manhattan since 1920. It averages about 5, no, 3 millimeters a year, you can see, but it goes up and down.

3 millimeters a year, by the way, is 1 foot a century. NOAA, the part of the US government concerned with oceans and atmospheres, says that over the next 30 years this graph is gonna do that. Remarkable, who am I to challenge NOAA, right? But we'll know soon enough whether that's gonna happen or not.

And in fact, other researchers say you shouldn't be using these models because they're not very precise, they're not very accurate, and so on, giving an impression of false confidence to users. Well if you can't believe the models about what's gonna happen going forward, how might we get a handle on how things are gonna change as the globe warms?

Well we can look at the past. So here's the global average temperature since 1850, and you can see that since 1900 or so it's gone up by about 1.3 degrees to the present. That's just about the same amount of warming that the UN predicts on average to the end of the century, 2100.

What will be the impacts? Well we don't know, but we can see how the globe has fared during the previous 120 years. And the answer is humanity has prospered as never before. The global temperature went up by 1.3 degrees. The population went up by a factor of five.

Life expectancy went from 32 years to almost 73 years. The literacy fraction jumped by a factor of four. GDP per capita went up by a factor of seven, etc., etc. And the death rate from extreme weather went down by a factor of 50, even as the globe warmed 1.3 degrees.

That doesn't say things are gonna be perfect over the next 80 years, but it sure gives some sense that humanity is perfectly capable of adapting and flourishing as conditions change. Here's one example of that, agriculture, this is 60 years' worth of agricultural data globally. The land area used for grain production hasn't gone up at all, as shown by the lower trace.

But the population, of course, has gone up. The grain yield, which is how many bushels per acre you get, or tons per acre or whatever, has gone up spectacularly as agronomy has gotten better. And the grain production, how much grain the world actually produces, has also gone up by 250%, even as the globe warmed.

If you look at weather losses, how much GDP did you spend because of extreme weather events? This is global data, you can see first of all that it hovers around 0.25% of GDP. Second, you can see it's actually gone down a little bit. Again, people who are concerned will say well this is just gonna go up and up.

But in fact, as the world develops we get more and more resilient and able to deal with extreme weather events. And in any event, right now it's only 0.25% of GDP globally. What about the economic impacts? Well last March, about four months ago, the White House put out a white paper that summarized the result of 12 independent peer-reviewed studies of how much warming would affect the US GDP, this graph comes from that report.

And what you can see is that as the change in global surface temperature, it's in degrees Fahrenheit because this is a US graph. Okay, we're currently at that vertical line, and you can see that it's expected that warming has affected the US GDP. Those different lines indicate different models.

The black line is the average, you can see it's down at less than 0.1%. And that if we go out to the extreme end of this chart, which is where we would be under the Paris 2 degree warming, you can see it's still at 2%. In other words, the economy would be 2% smaller in 2100, let's say, than it would have been otherwise.

It's in the noise. Bjorn Lomborg in another paper compiled a similar set of estimates for the globe as a whole. And again, the takeaway is a few percent for a few degrees. Well you might say well what about tipping points? And of course, people have studied that as well, there's a paper, it's another 1 or 2% for the tipping points.

And so, economically, this is in the noise. Now you might argue GDP is not the only thing that matters. There will be differential impacts, poor people versus rich people, etc. All true, but hardly a catastrophe or existential threat. Okay, let me turn to the second statement I wanted to make in that advocacy for rapid decarbonization globally.

Is immoral and it starts with demographics. This is the global population historically and projected out to 2100. And you can see we've just crossed 8 billion people right now. And according to this projection, we'll get to 10 billion by the end of the century. Most of the growth between now and the end of the century is in Asia and in Africa.

That means that the developed world, where there are one and a half billion of us, is getting older. The developing world is younger, and urbanization is proceeding at a spectacular pace. 50 million people a year, the equivalent to six New York cities a year, are getting created. Half of the world now is urbanized, 70% will be by the end of the century.

>> Steven Koonin: Steve Haber yesterday talked about the developed world bubble. We're sort of living in, I would say almost echo chamber. This graph makes it rather apparent. What's plotted here is, for a number of representative countries indicated on the right, the annual energy consumption per capita. How much energy did each person use parted as a function of the GDP per capita in constant $2017.

And you can see that there are lots of interesting things to understand about this chart. I some of us in the US, Canada, some other very developed countries use a lot of energy. We sit in the upper right corner, we have a relatively high GDP as a result.

In the middle of the graph, you find the European countries, a number of other middle countries that use about half the energy per capita of the US, have a somewhat smaller GDP. And down on the lower left corner, you see a set of countries whose energy use increases universally and monotonically as they get richer.

Richer countries use more energy, and when you're a developing country down in the lower left, your energy use is gonna go up a lot as you become better off. What is sobering about this chart is that there are only 1 and half billion people in the upper parts of this chart.

If you go down to the bottom left, you got about 6 billion people. And so it's pretty clear that as they improve their standard of living by using more energy, the energy demand is gonna go up. People down there, maybe some of you come from those countries or have been in them.

Life without energy is no fun, it means cooking and heating with what's politely called traditional biomass or wood and dung. The indoor air pollution from that is terrible, kills 2 million people a year. Without 24 hours lighting, you've got to study under extreme conditions. It's okay to eat romantically by candlelight, but studying by candlelight is no fun.

The inequalities are astounding, Nigeria consumes one-thirtieth the energy per capita that we do in the US. And there are 3 billion people in the world, three-eighths of the population that use less electricity per year than the average US refrigerator. And I will say with a little bit of embarrassment, I have three refrigerators in my house in New York.

>> Steven Koonin: So if you combine the demographics of population growth with the need for energy as you develop, you get a strong growth in energy consumption. This is shown projected out to 2050, again, you can see most of the growth, about 50% in total, is there in Asia. And the developed world is pretty flat and where are we gonna get that?

If we don't change our policies, most of it is gonna continue to come from fossil fuels even though renewables may grow strongly,. Fossil fuels continue to dominate. This shows where the world got its energy from different sources from 1965 up until the present. And you can see that the great bulk of the world's energy comes from the bottom segments, oil, coal and gas.

The others growing a little bit, but not a tremendously rapid amount. The world has spent about $4 trillion over the last decade trying to change the energy mix. But fossil fuels still amount to just about 80% of the world's energy. And that means that there are going to be increased emissions from the developing world.

Whatever we do in the OECD, you can see right now emissions are just about half and half the vertical line, 2020. But as we go out to mid century, the developing world dominates. That's because fossil fuels are in fact the most reliable and convenient way for those countries to get the energy that they need.

There's a guy, political scientist, economist named Anthony Downs, who died about two years ago. He wound up working at Brookings, but for the early part of his career in the 60s, he was working at UCLA, watching the smog get worse and worse as more and more people were able to acquire automobiles.

And he wrote a wonderful paper called up and Down with Ecology 1972, I would highly recommend it. What he said there is that the elite's environmental deterioration is often the common man's improved standard of living. And so we in the developed world might clutch our pearls and recoil with horror at the threat of human induced climate change.

The folks in the developing world have much bigger problems, more immediate problems and more readily soluble. And so when we say the science compels us to make emissions reductions, they say, what do you mean us? So you have PM Modi in India saying the colonial mindset hasn't gone.

The developing nations are closing to us, the path that made them developed. And the ex president of Niger, who was just opposed in a coup, said about a year ago, Africa is being punished by decisions of Western countries to end public financing for foreign fossil fuel projects by the end of 2022.

You see this when the IMF of the World bank refused to fund fossil fuel projects. We're gonna continue to fight, we have fossil fuels that should be exploited. So there is a moral issue for those of us who are sitting fat and happy in the developed world. What are we gonna tell these folks?

Nobody's got a good answer, as I've gone around and asked that question.

>> Steven Koonin: Finally, let me turn a little bit to rapid national decarbonization. You say, well, okay, the US-EU should lead the way and reduce our emissions. Well, it's not so simple, because, to borrow a phrase from a movie recently, energy touches everything, everywhere, all the time.

It is one of the fundamental systems of society. Energy systems evolve very slowly because they need to be reliable and the assets last a long time, power plants, refineries, automobiles, etc. So you tinker with the energy system at your peril. If you try to make the energy system change too rapidly, it is going to be, it will be extraordinarily disruptive.

The cost and reliability of energy services. California here has very close to the highest electricity rates the country because of the strong dependence on solar and wind. We're going to change the way people are employed. You put in electric cars, mechanics will disappear the flow of funds, you lose the fuel tax.

What are you gonna do to replace that? Financing an electric car, as an example, costs a lot more upfront, but has lower operating costs, at least until the government starts taxing it to recover the lost fuel revenues. Domestic manufacturing costs increase. If you make energy expensive, manufacturing gets expensive.

Germany, which has the highest energy costs almost in the world, is seeing an outflux of manufacturing as the manufacturers decamp for cheaper energy costs elsewhere. You deploy immature technologies, you're gonna have to replace them. Wind is not quite up to snuff yet, and so we're seeing a lot of wind turbines having to get replaced before their projected end of life, 30 years.

It's turning out to be more like 15, because we haven't taken the time to mature the technologies. We need new supply chains. A major part of the energy transition is going to be technologies that employ exotic materials, relatively exotic. Lithium, more copper, cobalt, manganese, rare earths, because renewable energies have to harvest energy over very large areas, and they need to be very efficient at harvesting it.

So you need fancy magnets and conductors and so on. So you got to rejigger the supply chains and right now, China has got a market on the processing of these exotic materials and that's causing grief, if you like, in the energy transition. How much is it going to cost?

Well, it's hard to estimate, but people try. Number of estimates show that to go net zero by 2050 in the US, is gonna cost somewhere between 5 and 7% of GDP each year. That's one and a half trillion dollars a year. We could do a lot with one and a half trillion dollars besides trying to reduce our emissions when the US is only 13% of global emissions anyway and the rest of the developing world is going up rather than going down.

Globally, the numbers are about the same. So we should be thinking hard before we commit to investing 1.5 trillion a year to go net zero. And we're already starting to see pushback on these overly stringent regulations that are aimed at decarbonizing the economy. In Europe, we probably are seeing what people call peak green.

There's been pushback in Germany, in France, in the UK and Netherlands about how you heat your homes, whether you can ban an internal combustion engine by 2035 and so on. And there are political shifts that are underway as a result of people, consumers being unhappy about these. The mandates in the US are just beginning to affect everyday consumers and I think we will see similar pushback.

People will start asking, tell me again why we're doing all of this? As electricity costs go up, as electric vehicles cost more than internal combustion engines and so on. All right, so I've given you a lot of things that are somewhat on the cup is half empty side.

What do I think we should do? I think the first thing we've got to do is cancel the climate crisis. When the UN secretary general stands up and says we're on the highway to climate hell with our foot on the accelerator, that's just flat wrong and it is counterproductive.

At the same time, I think we need to acknowledge the task and the challenges in trying to reduce human influences on the climate. We need to have better and more transparent representations of the scientific knowns and unknowns and the technology potentials to non experts. And more generally, I think the public and the decision makers, including policymakers, have to become more literate about energy and climate.

We need to work harder on the science observations, understanding we must not constrain the developing world's energy supply. If we in the West, US-EU try to do that, China is going to step in and make sure that they get the energy, and that's not a good thing geopolitically.

We need a greater focus on adaptation and resilience. If we can't reduce emissions sufficiently rapidly and I think there are many reasons why we can't. All we need to understand how to better adapt to a changing climate. One of the things we don't do is to prepare for the past.

The terrible tragedy we've seen in the last week or so in Maui was anticipated by many more than a decade ago. And there are reports that say you should do x, y and z and of course nobody did, most of them.

>> Steven Koonin: And of course for the developing countries, we need to make sure that they improve their lot so that they can be more resilient.

Technology is really important, we've got to make a technologies that are low or zero emissions about as cheap as fossil fuels. I have my own favorite list there I won't go through in any detail. And then finally I think graceful decarbonization. Right now governments are just throwing stuff at the wall and trying to see what sticks.

So you've got for example in the US, Ira, I think totally unjustified subsidies for wind and solar when they cannot be the primary source of electricity in the country. So we need to figure out these pathways involves technology, business regulation, behavior. Nobody has done that, we're just all running around saying the sky is falling.

Last chart, I thought it would be good to just offer a couple thoughts on S&T input to policy more generally. Not just climate and energy, but pandemics, for example, other S&T artificial intelligence. For those of you who are not experts, as most of you aren't, as I read your bios in S&T matters, don't be afraid to ask dumb questions.

Sometimes they can elucidate or reveal gaps in our understanding or things that the advisors are not telling you about. Ask about the data, coverage, bias, uncertainties, we saw that in COVID. Ask about model protections, how do you know the models are right? What's the range of models that you get, for example, for the spread of Covid-19 or for climate?

Do not rely on the media for S&T input in these policy matters, they get it completely wrong. It's like shooting fish in a barrel to write op eds that pick out one another media story and confront it with the real data in climate and energy. Get yourself out of the echo chamber, look for diverse perspectives among the scientists and engineers, and welcome bad news.

If everybody tells you the same thing you wanna hear, that's not very good at all. Paul Simon wrote 60 years ago, almost man hears what he wants to hear and disregards the rest. So look for that diversity of perspective, opinion, and finally, don't misrepresent the science to justify a decision.

Make that balance that I talked about at the beginning, explicit. Yes on the one hand, on the other hand, and so on. Having been a scientist most of my life, and only gotten involved in policy matters, I would say in the last 20 years, I at one point heard the phrase science informed policy.

And I thought when I heard it, well, of course, what other kind of policy is there? And then I discovered that you often see in climate issues policy informed of science, namely, that the description of the science is meant to conform to what policymakers would like to have happen.

So I leave you with those general thoughts and welcome any comments or questions that you might have.