Updated: Nov 17, 2019
How bad is Global Warming going to get, and how can we fix it?
By now you understand that burning fossil fuels will increase the CO2 content and drive the temperatures up. During the Cretaceous Epoch, about 60 million years ago, the Earth had over 1700 ppm CO2, no ice caps (breadfruit trees growing in Antarctica), and the St. Louis area was on the coast of the Midwest Ocean. Humans could have survived in the Cretaceous but I’m not sure all 10-billions of us would make it. In any case, I don’t think there are enough easily accessible fossil fuels left to reach Cretaceous levels of CO2, and the dinosaurs are gone anyway.
However, if we look at the big picture it may already be too late for the US to impact Global Warming. If we look at current global energy usage and the fraction that is renewable energy in figure 11 on the right, we see the current rapid increase in energy generation, and that currently Wind, Solar, and Geothermal energy contributes roughly 2.2% of the world total while Gas, Oil, and Coal contribute 85% (the remaining 12.8% is Hydroelectric and Nuclear).
Figure 11 - Global Energy Generation by Year and Source
For easier cost calculations we converted gigatons of oil into terawatt-hours/year in Figure 12 below. As you can see we need to replace roughly 50,000 TWh/y of power plants by 2050 if we’re going to meet the Green Revolution’s plans. That is patently absurd, but we need to generate costs to better understand our viable options
Figure 12 Global Energy Consumption in Terawatt-hours per year
To understand how much various solutions are going to cost, we will look at existing and predicted cost data for all power options, and we cover that next.What is eliminating all fossil fuels going to cost? There are two types of power costs to consider.
The first is the capital cost to build a power plant and connect it to the grid. If this cost is too high the Public Utility can’t afford to update its infrastructure and the government will have to bear the costs. That is probably a non-starter. The average capital costs for current candidate power plants without connection costs is shown in figure 13 on the right, (All cost data is from reference 6.)
Figure 13 Capital Costs for candidate Power plant types
The second cost we need to consider is the Levelized Cost of Electricity (LCOE) shown in figure 14 below. The LCOE is the average cost of electricity from the plant over its thirty-year lifetime. If the LCOE for the new green power plant is significantly higher than the fossil-fuel power plant it is replacing, the increase in their electric bill is going to be very hard to sell to the consumers. Fortunately, the LCOE data indicates that except for advance combined cycle (ACC) natural gas this should not be much of a problem.
Figure 14 Levelized Cost of Electrical Power Generation in US by Source
Now that we have the data, what does it tell us. First, we will address capital costs. Our favorite green power plants need to be located in sites favorable to wind and sun and these are often not located near their costumers, so connection costs will be high. If we only use solar PV and windmills for peak and fill-in power, and use type IV fission power plants for base power, we can eliminate batteries and most connection expenses. In this case the world needs roughly 1.7x10^9 kWe of renewable power and 4.0x10^9 kWe of type IV fission plants. Assuming a 50-50 split between wind and solar power the renewables’ capital cost will be 2.26 Trillion dollars and the nuclear power plants will cost 15.1 Trillion dollars for a total of 17.36 Trillion dollars. The idea is not to replace the existing fossil-fueled power plants all at once but as they wear-out and then to replace them with plants that provide cheaper energy to the consumer. We can do that because I’m predicting that type IV fission plants will use thorium fuel which is four times more abundant than uranium and doesn’t require expensive enrichment.
Let me give an example as to why I don’t want to eliminate nuclear power and go entirely with renewable sources. In figure 9 we saw that that the average windmill output varied from 40% to 25% of capacity based on the season. If we are relying on windmills for base power, we need to install over 1/25% or four+ times the base power requirement in windmill capacity so we generate enough energy while the wind is blowing to charge the batteries to provide the base power while the wind isn’t blowing during the worst season. The “plus” is added to account for the losses incurred charging and discharging the batteries. The bottom line is that going entirely with windmills and solar PV plus batteries more than doubles the already high capital costs to achieve carbon-free energy. I calculate the cost for the world going carbon free with just windmills, solar PV, and batteries to be 37.2 Trillion dollars. We can’t afford that no matter what the Green Revolution Warriors are telling you, and it’s not going to happen by 2050. We will replace existing fossil-fueled infrastructure as it wears out, and we will replace it with a combination of nuclear, wind energy, solar PV, or bio fueled power plants, whichever is most appropriate for each particular use and location. I predict it will be well past 2080 before most fossil-fuel infrastructure is gone, and that is what I show in these results.
From a system engineering standpoint, the answer to this problem is obvious. Continue to develop renewable energy sources (windmills and solar farms) and build long-distance high voltage transmission lines to interconnect major consumers of electricity with the deserts and plains where renewable energy can be generated efficiently. This is almost a no-brainer, but politics has slowed building new high voltage transmission lines down to a crawl (the NIMBY factor). We are still going to need peak and backup power (remember, windmills and solar farms are time and weather dependent), and for those I would go nuclear, but not the nuclear we have now.
Nuclear power plant technology has changed radically over the last decades. We now have designs for Molten-Salt Fission Reactors using Thorium as fuel that generate almost no long-term nuclear waste to store and can be operated in a manner to make it impossible to generate bomb-grade material. Unfortunately, the Nuclear Regulatory Commission (NRC) has made licensing new reactor designs so onerous that all advance nuclear testing has moved overseas. This is a definite show-stopper.
In addition, the existing nuclear power industry has exceeded their accident quota by a large margin, so I think we are going to need a fresh start. I recommend we embrace small local, long-lived, nuclear power-plants (~ 10 MWe) that can be mass-produced in a factory, then delivered by truck and installed in weeks, not years. There are numerous designs available but the one I favor is the Terra Power by Intellectual Ventures, a local Bellevue Washington company where I know the chairman. This particular system is designed to be buried underground and then operate for 100 years with only periodic inspection and maintenance.
The critical feature is that it is designed to be fail safe. If anything goes wrong, it shuts down and just sits there until maintenance arrives. No meltdown, no radiation leaks, and no trauma. Every 100 years the factory truck comes by, loads it up, and takes it to the reprocessing facility where the nuclear waste and remaining fuel is removed and processed.
Our problem is that there is very little government funding going into design and test of these small, fail safe fission reactors and the NRC is hostile to even building a test reactor? Small fission reactors would be only be the first step in my new recommended Green Energy program. Did you know that there are five companies in North America doing preliminary testing on 10 MWe fusion reactors? I’m betting that at least one of these companies will be successful within the next ten years and then we can start replacing the 10 MWe fission reactors with clean, efficient 10 MWe fusion reactors. Since the NRC is not hostile to new fusion reactor designs this may be our only hope. Again, very little government funding is going to support these five commercial fusion reactor developers.
The 900-pound gorilla in the room is politics. Our political leaders offer small incentives for building and using renewable power but then want to tax and penalize transportation systems where there is really no option but to use fossil fuels. Solar panels and windmills are now very affordable, and our governments needs to move on to the next phase, i.e. incentivize the construction of long distance high-voltage transmission lines and new technology nuclear facilities. I recommend that the government match the current private funding of all the competitive fission and fusion power plant developers as soon as possible.
As you can see from figures 7 and 11 eliminating fossil fuels by 2050 worldwide is a joke and we need to plan for a world where significant fossils fuels are burned far into the future.
Note, in figure 6, that if the US and Europe stopped all CO2 emissions tomorrow, the rest of the world would still be dumping 30 Gigatons of CO2 into the Earth’s atmosphere every year.
Therefore, I don’t recommend trashing our successful economy on a crash program to reduce US CO2 emissions, because we’re only 1/8 of the current worldwide emissions and dropping, so it isn’t going to make that much difference in global warming. I do recommend we continue to encourage the development of affordable renewables and lead a worldwide effort to fund a sensible program to develop small safe nuclear power plants, so we do our part to reduce CO2, but we also need to understand that some of our infrastructure is going to continue to use fossil fuels and emit CO2. This is because there really is no feasible option to completely eliminate them using the technologies we have available to us. Likewise, most of the developing world is going to continue to burn fossil fuels and drive the CO2 level to 700 ppm and beyond, because they want to better the life for their population, and I can understand that.
Just how bad is it going to get? For that I will borrow data from the IPCC (Intergovernmental Panel on Climate Change), a UN sponsored panel of Scientists who have spent over one billion dollars studying global warming over the last decade. They have about 23 models with specific scenarios of emission of CO2 and other greenhouse gases over time (see Figure 15 below). In one scenario, RCP8.5, the world continues as shown in Figure 11, with escalating use of fossil fuels and not much renewable energy.This worst-case scenario results in a world temperature rise of up to 5.4 degrees Celsius and world CO2 above 1000 ppm. I believe this scenario is too pessimistic and if non-fossil fuel energy sources were to be made affordable to the developing world they would use them.
Figure 15 Atmosphere CO2 results with various emissionscenarios
The other extreme assumption is RCP 2.6 where the world immediately embraces green energy this year and all the nations in the world stop non-energy related infrastructure development immediately, and focus on solar farms, windmills, and nuclear power plants. We would also have to make synthetic hydrocarbon fuels from recycled materials or launch dozens of Space Solar Power Satellites in Geosynchronous Earth Orbit (GEO) so they could beam down focused laser beams to power long-haul trucks, long-range aircraft, and remote power installations. These actions would cause CO2 emissions to peak about 2024 and fall to zero by 2070! Somehow, I just don’t think that is going to happen.
My personal opinion is that the most reasonable assumption is that the world’s response will fall somewhere between RCP6 which sees a CO2 peak of over 800 ppm, and RDP4.5 which sees a peak CO2 of around 700 ppm. Yes, this is pessimistic, but I am trying to be realistic because tens of Trillions of dollars of investment are involved. In RCP4.5 emissions keep increasing through 2040 and start declining after 2050. In RCP6 emissions continue to increase until 2080 before finally falling off. My predicted scenario would result in world CO2 emission peaking about 2060 and dropping to 2015 emission levels (30 Gigatons/year) by 2100. The IPCC has plotted probable world temperature changes for each of these scenarios and they are shown in figure 16 below. The solid lines are the average temperature increase over time with a baseline set of assumptions.
Figure 16 Average Global Temperature Changes with Emission Scenarios
This data shows that with my pessimistic (realistic?) emissions scenario halfway between RCP 4.5 and RCP 6 we can expect an average rise in the world’s temperature of approximately 2.5 degree Celsius. How will that impact our Great-Grand-Children?
The IPCC also plotted the expected impact on Sea Level relative to the average in the year 2000 (see Figure 17 below) and this shows an expected ocean sea-level rise for a scenario halfway between RCP 4.5 and RCP 6 to be roughly 1.5 m (5 feet). Remember, I’m trying to be as realistic as possible, but this impact is huge. My family owns waterfront property in the San Juan Islands near Seattle and a five-foot increase in sea level would wipe out the beach entirely at high tide. This problem just became personal! It will also impact millions of other businesses and property owners all living near the coast all over the planet. The total cost to raise facilities and build sea walls boggles the mind.
Figure 17 – IPCC Projections of Sea Levels vs Time
Beyond the impact on waterfront properties how will rise in temperature effect industry and farming? As it turns the IPCC has been investigating that very question and their answers are shown in Figure 18 below.
According to Figure 18 our selected CO2 rise between RCP 6 and RCP 4.5 would result in a loss of US Gross Domestic Product (GDP) of just under 2% relative to the GDP in 2100 with no temperature rise. Note that at a 1.8% average growth rate the GDP will quadruple in the 80 years between now and 2100, so a gradual drop leading up to a 2% reduction in 2100 will have little effect near term but will essentially negate growth in the long term. This tells me that Global Warming will probably be a huge inconvenience and a money sink, but unless we let it get out of control, it will not be a threat to civilization. The world needs to respond to this threat in a timely and well-thought-out manner to mitigate the problem. Yeah, good luck with that. My motto is “Remember the Cretaceous” for that is where we are headed if we do nothing.
Figure 18 – Reduction in US GDP due to Global Warming
One option is to be less reactive and more proactive with respect to this threat. This means that the ice cap and glaciers are going to continue to melt and the sea level is going to rise unless we take active steps to reduce the Earth’s temperature. Our options are to collect and sequester CO2 (there are demonstrators being built to test the economics of this approach (3,4); or to reduce the amount of sunlight being absorbed by the Earth’s surface. For instance, if most of the Earth’s unusable land were covered by a highly reflective surface the average temperature should start dropping. I would use coated-mylar stretched between poles about ten feet off the ground. The mylar coating could treated with special coatings to reflect visible light and radiate in the IR spectrum (we coat space radiators with this material). Likewise, if an ingredient were added to airline jet fuel that seeded high altitude clouds, the sunlight reflected by clouds could be increased to the point where the average atmospheric temperature started dropping. Cloud seeding could be as simple as adding sulfur back into jet fuel (5).
In summary, I think we can agree that global warming is real and it’s going to get worse. The current Green Energy initiative is going to cost lots of tax money, but it’s really not going to make a significant difference with respect to the real problem, which is international in scope. It is absolutely essential we fund development of small, safe molten salt nuclear power plants, but right now only the Chinese and Indians are doing that. Please bring the nuclear power plant issue to the attention of your Congress critters.
There is an alternative approach which is to reduce the amount of sunlight being absorbed by the Earth’s surface. This work is progressing in almost stealth mode and it deserves to be brought into the open and discussed publicly. Reflecting sunlight may be cheaper and easier overall and could even buy us the time we need to reverse the burning of fossil fuels. We need to study all options to solve this worldwide problem.
1. Tsao, Jeff, “Some Simple Physics of Global Warming”, Sandia National Laboratories, April 2008.
2. Adapted from http://en.wikipedia.org/wiki/Greenhouse_effect