As promised, Professor Mark Jacobson has answered Era's questions about climate change. What's more is that the professor took time to answer every single question forwarded!
If you submitted a question but cannot find it in the OP, it is likely due to one of the following reasons:
If none of the above apply to your question, you should find Professor Jacobson's response to your question in this post.
The questions will be divided into two categories: 'ESSENTIAL' and 'TANGENTIAL'. The 'essential' questions are questions that directly focus on the nature of climate change, addressing climate change, and/or its impact on life on Earth. The 'tangential' questions are questions that relate to climate change in a more indirect or roundabout way, or questions that focus on Professor Jacobson's specific methodologies as a scientist/researcher.
Also, you may notice that your question has been modified to a degree. This was done to ensure that questions were presented with clarity and coherent grammar, and/or to make sure that the question fully complied with the rules (e.g. some questions had multiple parts and had to be simplified per the interview rules).
In addition, since there were some posts in the submission thread that called Professor Jacobson's expertise into question, based on criticism from the professor's peers in the past, I have given the professor the opportunity to respond to some of these criticisms and he has done so, as you will find in the 'CRITICISMS' section of this post.Now with all of that out of the way, let's get on with the Q&A!
FORMAT: To improve readability, I've changed the format to match adj_noun 's style: User responses will be in bold, Professor Jacobson's responses will be italicized.
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ESSENTIAL QUESTIONS:
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https://web.stanford.edu/group/efmh/jacobson/Articles/I/sad1109Jaco5p.indd.pdf
Although we have always believed a transition by 2030 is technically and economically possible, as proposed in the 2009 article, we believe that for social and political reasons, an 80% transition by 2030 and 100% no later than 2050 (and hopefully earlier, particularly in some sectors) is both achievable and more realistic. It is also a necessary timeline to return CO2 to 350 ppm by 2100
http://web.stanford.edu/group/efmh/jacobson/Articles/I/CountryGraphs/CO2ChangesWithWWS.pdf
and to avoid catastrophic damage from global warming and to eliminate the 7 million air pollution deaths per year from air pollution.
https://web.stanford.edu/group/efmh/jacobson/Articles/I/AirPollutionDeath.pdf
Based on our calculations, we think the Green New Deal (a 100% clean, renewable energy system) will reduce energy use by half thus reduce aggregate (absolute) energy costs by about half. By reducing air pollution and climate costs in the U.S., it will also reduce aggregate (absolute) social costs by 5/6 while creating many more jobs than lost.
https://cleantechnica.com/2019/03/09/why-the-green-new-deal-cuts-consumer-energy-costs-unemployment/
Adding carbon capture equipment to a coal or gas plant increases air pollution and mining of coal and gas and decreases CO2 only about 10% over 20 years, not 90%. This is before even accounting for leaks after the carbon is stored or used:
https://web.stanford.edu/group/efmh/jacobson/Articles/I/NatGasVsWWS&coal.pdf
The same poor result applies to synthetic direct air capture.
https://web.stanford.edu/group/efmh/jacobson/Articles/I/AirCaptureVsWWS.pdf
No, but sea levels will rise (up to a maximum of 80 m, which is how much sea level is stored in all the world's ice, mostly in the Antarctic).
Reforestation and reducing deforestation is the only effective means of drawing carbon out of the air, so yes that is a good idea and has additional benefits as well (e.g., vegetation absorbs air pollution as well).
https://web.stanford.edu/group/efmh/jacobson/Articles/I/NuclearVsWWS.pdf
https://web.stanford.edu/group/efmh/jacobson/Articles/I/AirCaptureVsWWS.pdf
2) Support policymakers who will put this solution into policy.
3) Make changes in your own life to meet this solution.
This is the best we can do.
1) Electrify everything and provide the electricity with clean, renewable energy.
2) Use electric heat pumps for air and water heating and air conditioning.
3) Use electric vehicles and hydrogen fuel cell vehicles, where the hydrogen is from electricity.
4) Electrify industry.
5) Reduce energy use.
2) Support policymakers who will put this solution into policy.
3) Make changes in your own life to meet this solution.
https://web.stanford.edu/group/efmh/jacobson/WWSBook/WWSBook.html
http://scpd.stanford.edu/search/publicCourseSearchDetails.do?method=load&courseId=87803904
https://web.stanford.edu/group/efmh/jacobson/Articles/I/GeoengineeringVsWWS.pdf
In addition, wind, solar; batteries for storage and electric cars; hydrogen fuel cell vehicles for heavy, long-distance transport; heat pumps (for air and water heating and air cooling) will grow substantially.
More damaging air pollution (since it gets worse with higher temperature).
More severe hurricanes and weather in general
More droughts/floods, especially coastal flooding.
Large shifts in agriculture
Greater heat-related deaths
More malaria, dengue fever
Greater coral reef loss/ocean acidification
Greater loss in biodiversity
More climate migration
https://climate.nasa.gov/vital-signs/global-temperature/
2) Use electric heat pumps for air and water heating and air conditioning.
3) Use electric vehicles and hydrogen fuel cell vehicles, where the hydrogen is from electricity.
4) Electrify industry.
5) Reduce energy use.
2) Add a more bike lanes to roads.
Some people will be exposed to more extreme heat, and this will kill or injure more people.
Others will be exposed to more severe weather.
Adjustments will be needed but I don' think the supply chain will be hampered too long since there will be financial incentives for everyone to secure the supply chain. Plus, there are many ways to produce different technologies and many different technologies that will be implemented.
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TANGENTIAL QUESTIONS:
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Yes, 4.6 billion years ago, the Earth was molten, which is why that time is called the Hadean eon.
And 100 million years ago, the Earth was ice free - but no people lived then. Now we have 7.5 billion, with most people living along coastlines.
http://web.stanford.edu/group/efmh/jacobson/Articles/I/CombiningRenew/PNASReplyClack.pdf
The problem was that PNAS published a paper with false information and did not correct it.
2) Two independent peer-reviewed articles have refuted the Clack et al. paper:
The first one,
https://www.sciencedirect.com/science/article/pii/S1364032118303897
concluded that Clack's and other critiques of 100% contain "factual errors, questionable assumption, important omissions, internal inconsistencies, exaggerations of limitations, and irrelevant arguments."
It goes on to state,
"Of particular concern is that PNAS published the Clack et al. article as a Research Report instead of a Letter to the Editor, although the article contained no original research -- it only criticised a genuine research paper with claims that generally don't stand up to examination."
and
"Our assessment is that Jacobson et al. have clearly refuted all but one of Clack et al. error claims. However, this is a minor 'error.'"
The second paper that debunks the Clack et al. paper and other critiques of 100% renewables is
https://www.sciencedirect.com/science/article/pii/S1364032118303307
which states, "As a result, we conclude that the 100% renewable energy scenarios proposed in the literature are not just feasible, but also viable."
3) The main conclusions of the Clack et al. paper were derived from their own errors, not from any error in our PNAS paper. For example, they pretended our Table 1 contained maximum values when they were fully informed and aware it contained average values. They used their own error to then claim we make modeling errors when it was their own mistake that produced this claim:
http://http://web.stanford.edu/group/efmh/jacobson/Articles/I/CombiningRenew/18-02-Correction.pdfobson/Articles/I/CombiningRenew/18-02-Correction.pdf
4) Three authors on the Clack paper (Sweeney, Weyant, Victor) are being paid by Trump to fight climate action
http://blogs2.law.columbia.edu/clim...nts/2018/20181015_docket-615-cv-1517_na-1.pdf
Two others (Caldeira, Qvist) wrote plans for the world to go all nuclear:
https://www.theguardian.com/environ...he-only-viable-path-forward-on-climate-change
https://www.nytimes.com/2019/02/05/...uture-joshua-s-goldstein-staffan-a-qvist.html
Others have research interests in technologies (e.g., natural gas, carbon capture) we do not include. These facts all speak to their motivation.
******
In sum, I and many others disagree with the premise of the question, that 100% renewables is not within reach. In fact, 8 countries are at 95-100% renewable electricity (not all energy) and 61 countries have commitments for 100%.
There are many ways to get to 100% WWS and storage (electricity, heat, cold, hydrogen storage) in all energy sectors at low cost.
http://web.stanford.edu/group/efmh/jacobson/Articles/I/CombiningRenew/WorldGridIntegration.pdf
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CRITICISMS:
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Further, there was no error in our hydro calculations for the PNAS paper, only misrepresentation by the Clack et al. authors about what was done :
http://web.stanford.edu/group/efmh/jacobson/Articles/I/CombiningRenew/18-02-Correction.pdf
To the contrary, the idea of uprating hydro plants (increasing their nameplate capacity without increasing annual average power output) in order to help meet peaks in demand was a novel idea, which helped to earn the PNAS paper the Cozarelli Prize from PNAS. The U.S. Bureau of Reclamation
https://www.usbr.gov/power/edu/pamphlet.pdf
states that "uprating of existing hydro generator and turbine units is one of the most immediate, cost-effective, and environmentally acceptable means of developing additional electric power. Since 1978,..uprating added more than 1,600,000 kW at avg cost $69 per kW"
Whether hydro plants can be uprated to the level proposed in the paper is a social and political question, not a technical or even economic question See, for example, the calculated costs of such uprating here:
http://web.stanford.edu/group/efmh/jacobson/Articles/I/CombiningRenew/Clarification-PNAS15.pdf
In fact, it is much easier to do what we proposed than to implement the proposed schemes by two Clack authors (Caldeira and Qvist) who want to move the world almost entirely to nuclear power
https://www.theguardian.com/environ...he-only-viable-path-forward-on-climate-change
https://www.nytimes.com/2019/02/05/...uture-joshua-s-goldstein-staffan-a-qvist.html
or the scheme of Clack to convert the US entirely to HVDC transmission without any storage whatsoever.
https://www.nature.com/articles/nclimate2921
It was hypocritical for these authors, the only ones that claimed to perform work on a 21-author paper, to criticize a potential plan without criticizing their own even-more-difficult-to-implement plans.
There are at least 42 peer-reviewed papers supporting 100% renewables
http://web.stanford.edu/group/efmh/jacobson/Articles/I/CombiningRenew/100PercentPaperAbstracts.pdf
and independent peer-reviewed papers find 100% feasible.
https://www.sciencedirect.com/science/article/pii/S1364032118303897
https://www.sciencedirect.com/science/article/pii/S1364032118303307
so the claim that more realistic plans than 100% renewable is not substantiated.
https://www.usbr.gov/power/edu/pamphlet.pdf
states that "uprating of existing hydro generator and turbine units is one of the most immediate, cost-effective, and environmentally acceptable means of developing additional electric power. Since 1978,..uprating added more than 1,600,000 kW at avg cost $69 per kW"
Whether hydro plants can be uprated to the level proposed in the paper is a social and political question, not a technical or even economic question. In fact, it is much easier to do what we proposed than to implement the proposed schemes by two Clack authors (Caldeira and Qvist) who want to move the world almost entirely to nuclear power or the scheme of Clack to convert the US entirely to HVDC transmission without any storage whatsoever. It was hypocritical for these authors, the only ones that claimed to perform work on a 21-author paper, to criticize a potential plan without criticizing their own even-more-difficult-to-implement plans.
The 12 GW being referred to has nothing to do with uprating existing hydro plants. It has to do with powering non-powered dams.
https://web.stanford.edu/group/efmh/jacobson/Articles/I/NuclearVsWWS.pdf
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And that concludes the Q&A!
I would again like to thank Professor Jacobson for his time, as well as all of the users who submitted their questions. It is my hope that through this exchange, we all will have learned something valuable and do everything that we can to combat climate change in a way that causes the least amount of harm.
Thank you, everyone!
If you submitted a question but cannot find it in the OP, it is likely due to one of the following reasons:
- Your question did not comply with the rules that were established in this post
- Your question was too similar to a question that was already asked
- Your question was submitted after you already submitted a question
- Your question was submitted after the deadline
- Your question was deemed too inappropriate to be forwarded
If none of the above apply to your question, you should find Professor Jacobson's response to your question in this post.
The questions will be divided into two categories: 'ESSENTIAL' and 'TANGENTIAL'. The 'essential' questions are questions that directly focus on the nature of climate change, addressing climate change, and/or its impact on life on Earth. The 'tangential' questions are questions that relate to climate change in a more indirect or roundabout way, or questions that focus on Professor Jacobson's specific methodologies as a scientist/researcher.
Also, you may notice that your question has been modified to a degree. This was done to ensure that questions were presented with clarity and coherent grammar, and/or to make sure that the question fully complied with the rules (e.g. some questions had multiple parts and had to be simplified per the interview rules).
In addition, since there were some posts in the submission thread that called Professor Jacobson's expertise into question, based on criticism from the professor's peers in the past, I have given the professor the opportunity to respond to some of these criticisms and he has done so, as you will find in the 'CRITICISMS' section of this post.Now with all of that out of the way, let's get on with the Q&A!
FORMAT: To improve readability, I've changed the format to match adj_noun 's style: User responses will be in bold, Professor Jacobson's responses will be italicized.
_________________________
ESSENTIAL QUESTIONS:
________________________
The Green New Deal puts into policy what we have proposed since 2009, a 100% clean, renewable energy system for all energy sectors (electricity, transportation, building heating/cooling, industry).@UnpopularBlargh asks: What do you think of the Green New Deal?
https://web.stanford.edu/group/efmh/jacobson/Articles/I/sad1109Jaco5p.indd.pdf
Although we have always believed a transition by 2030 is technically and economically possible, as proposed in the 2009 article, we believe that for social and political reasons, an 80% transition by 2030 and 100% no later than 2050 (and hopefully earlier, particularly in some sectors) is both achievable and more realistic. It is also a necessary timeline to return CO2 to 350 ppm by 2100
http://web.stanford.edu/group/efmh/jacobson/Articles/I/CountryGraphs/CO2ChangesWithWWS.pdf
and to avoid catastrophic damage from global warming and to eliminate the 7 million air pollution deaths per year from air pollution.
https://web.stanford.edu/group/efmh/jacobson/Articles/I/AirPollutionDeath.pdf
Based on our calculations, we think the Green New Deal (a 100% clean, renewable energy system) will reduce energy use by half thus reduce aggregate (absolute) energy costs by about half. By reducing air pollution and climate costs in the U.S., it will also reduce aggregate (absolute) social costs by 5/6 while creating many more jobs than lost.
https://cleantechnica.com/2019/03/09/why-the-green-new-deal-cuts-consumer-energy-costs-unemployment/
The only effective carbon-absorbing technologies are natural air capture by trees and reducing deforestation.@Menx64 asks: How effective do you think carbon-absorbing technologies will be to reduce Climate Change?
Adding carbon capture equipment to a coal or gas plant increases air pollution and mining of coal and gas and decreases CO2 only about 10% over 20 years, not 90%. This is before even accounting for leaks after the carbon is stored or used:
https://web.stanford.edu/group/efmh/jacobson/Articles/I/NatGasVsWWS&coal.pdf
The same poor result applies to synthetic direct air capture.
https://web.stanford.edu/group/efmh/jacobson/Articles/I/AirCaptureVsWWS.pdf
I don't think they are. For example, a big effort has been made in the U.S. to phase out the most polluting coal plants.Our roadmaps capture all polluters, since our goal is to go to zero emissions for everything to address air pollution and climate.
No, but sea levels will rise (up to a maximum of 80 m, which is how much sea level is stored in all the world's ice, mostly in the Antarctic).
@Cow Mengde asks: I've been reading about various Chinese re-greening projects like the Loess Plateau, do you think these kinds of projects can (if adapted world wide) help slow/reverse the effects of climate change?
Reforestation and reducing deforestation is the only effective means of drawing carbon out of the air, so yes that is a good idea and has additional benefits as well (e.g., vegetation absorbs air pollution as well).
Aside from the Vogtle reactors being built, which will take 15-16 years to complete from the time of initial planning to operation, there are no other nuclear plants being planned for construction in the U.S., and many are slated for retirement. So, I see only a decrease in nuclear power output over the next 10 years in the U.S. Worldwide, nuclear output in 2018 was 6% lower than in 2006, so there has only been a decrease in the usefulness of nuclear power as a climate change tool in the past 13 years. Nuclear takes 10-19 years between planning and operation and costs 4-5 times that of new onshore wind or utility solar PV so is no longer competitive. It also has meltdown, weapons proliferation, waste, mining lung cancer, and CO2 emissions issues, so there are multiple issues that make it not an attractive method of energy production going forward. Small modular reactors cause many of the same problems. Please see more details of all these issues here:@samoyed asks: What kind of future do you see for nuclear power in America?
https://web.stanford.edu/group/efmh/jacobson/Articles/I/NuclearVsWWS.pdf
Of the remaining candidates, Sen . Sanders has the most aggressive platform to combat climate change.@fauxtrot asks: What current Democratic presidential candidate has the best proposed platform to combat climate change?
In general, individuals can help by electrifying their homes (eliminating the use of gas, gasoline, and fuel oil) as much as possible, improving energy efficiency of their home, and reducing energy use. Electrifying means using heat pumps for air and water heating and air conditioning instead of gas devices; using an electric induction cooktop instead of a gas stove or electric resistance stove; using electric vehicles instead of gasoline or diesel vehicles. Also, going to LED lights, more energy efficient appliances; weatherizing your home. Telecommuting more; flying less; driving less; biking more; walking more. Eat food with a lower carbon footprint. These are just some examples.@ironichaos asks: What's one thing can I do before bed each night to help combat climate change (so I can sleep better at night)?
Provide incentives for alternatives to meat, which there are more and more of these days and/or tax beef consumption.@McStickenstein asks: What can policymakers do about beef consumption?
Direct air capture of CO2 just doesn't work effectively. Instead of reducing 90% of CO2, it reduces only about 10% over a 20 year time frame due to the high energy requirement of removal. As a result, it also increases air pollution and the mining for fossil fuels:@TheHunter asks: Is there a possibility for air scrubbers or sea scrubbers to remove any excess C02 from the air/water?
https://web.stanford.edu/group/efmh/jacobson/Articles/I/AirCaptureVsWWS.pdf
It would immediately help reduce the 78,000 air pollution deaths in the U.S. today and it would help reduce emissions of greenhouse gases proportionally to the reduction in global emissions it results in. However, given that 1 million is only 1/7,500th of the world's population and granted that the U.S emits more per capita than elsewhere, the impact would be much smaller than if the whole U.S. did the same.@Sabot asks: If 1,000,000 people in America just suddenly decided to switch to a zero emission lifestyle, would that even put a noticeable dent in climate change?
Sea level has potential to rise up to 80 m, which is the amount of water stored in all ice worldwide. Hopefully, we can limit sea level rise before we get close to that limit.@Seductivpancakes asks: How boned are coastal cities and islands like Hawaii and Japan?
Recycling helps, so the effort is useful, but its benefits have been modest in comparison with the total emissions from all sources that occur worldwide.@Takuhi asks: Over the last several decades, recycling has been the focus of the general public's limited interest in environmental issues. In retrospect, do you think that has been productive?
Eliminate combustion as a source of energy in favor of electrification and providing the electricity with clean, renewable energy.@Bumrush asks: Assuming what we have already done is not irreparable, what's ONE thing could we do to turn things around with the greatest benefit?
History has shown that reducing emissions does not damage economic growth. To the contrary, countries that do not transition their energy now are the ones that will suffer greater economic disadvantage. Onshore wind and utility scale solar PV are the lowest forms of new electric power in the world today; electric cars save people money over their lifetimes. Heat pumps also save money.@Phrozenflame500 asks: How do we promote decarbonization in large, developing nations such as China and India, while allowing them to maintain their high rates of economic growth?
Wind, solar; batteries for storage and electric cars; hydrogen fuel cell vehicles for heavy, long-distance transport; heat pumps (for air and water heating and air cooling).@Ubik asks: What forms of renewable green energy do you see the most potential in (from a mass adoption standpoint)?
Yes, because a lot of their operations can be cleaned up by electrifying agricultural equipment and processing machines and normal operations, and using electricity run on renewable energy is now less expensive than is using fossil energy for most applications.@sphagnum asks: Do you believe it is possible to mitigate climate change so long as the industries that primarily drive it (meat, energy, transportation, etc.) are privately held and run according to a profit motive?
I can't predict that.@Spiderz asks: How long do I have to get to Micronesia before it disappears?
1) Focus on the solution. Electrify all energy sectors and provide the electricity with clean, renewable energy and reduce all non-energy emissions. Use electric heat pumps for air and water heating and air conditioning. Use electric vehicles and hydrogen fuel cell vehicles, where the hydrogen is from electricity. Electrify industry. Reduce energy use.@louisacommie asks: Even if we stave off the worst scenarios, it is unfortunate that we most likely won't deal with this fast enough that some parts of the earth will be unlivable for the people there, leading to a major migrant crisis like the world has never seen, and will likely lead to an even bigger rise in fascism than we are seeing even today. If we are to prevent this, we obviously can't rely on incrementalism, and based on past precedent, we likely won't have a president and Congress and senate combination in 2021 that will take an uncompromising approach to climate change. Meaning, if we really want to protect everyone in the world from climate change, we need - in addition to electoralism - mass organisation with real leverage to force the biggest source of polluters that the United States has control over (it's corporations and the military) to end their damage. The million dollar question is: how do we achieve this organisation in a way that can actually produce results?
2) Support policymakers who will put this solution into policy.
3) Make changes in your own life to meet this solution.
This is the best we can do.
The solution is simple:@SneakyBadger asks: What is a promising but lesser known solution/approach to climate change that more people should be aware of?
1) Electrify everything and provide the electricity with clean, renewable energy.
2) Use electric heat pumps for air and water heating and air conditioning.
3) Use electric vehicles and hydrogen fuel cell vehicles, where the hydrogen is from electricity.
4) Electrify industry.
5) Reduce energy use.
I can't say exactly, but the Earth would be a lot warmer and climate damage would occur even more rapidly.@Eylos asks: What would be the climate impact in the world if the Amazon is turned into a savanna?
1) Focus on the solution. Electrify all energy sectors and provide the electricity with clean, renewable energy and reduce all non-energy emissions. Use electric heat pumps for air and water heating and air conditioning. Use electric vehicles and hydrogen fuel cell vehicles, where the hydrogen is from electricity. Electrify industry. Reduce energy use.@hanmik asks: What does it take for us to get on the right course again (how do we "save" humanity)?
2) Support policymakers who will put this solution into policy.
3) Make changes in your own life to meet this solution.
Sea walls are enormously expensive and don't pay for themselves, so they are not practical on a large scale. We need to solve the problem to reduce the impact. Otherwise, we will need to adapt.@djplaeskool asks: With such a large percentage of the population living in coastal cities and areas, has there been any tangible advancement in engineering or design for controlling potential sea level rise, like sea walls, dams, or dikes?
I teach about solutions and have a positive outlook because I know a solution is possible. I think this positive outlook can be seen in most every talk I give and in the new course I started teaching, "100% clean, renewable energy and storage for everything,"@i-Lo asks: How do you teach a 'feelings over facts' base comprising of millions about climate modelling systems in an approachable fashion that energize said folks to become environmentally conscientious without pushing them into climate despair (esp. in the face of big fossil fuel industry and governmental corruption) or apathy?
https://web.stanford.edu/group/efmh/jacobson/WWSBook/WWSBook.html
http://scpd.stanford.edu/search/publicCourseSearchDetails.do?method=load&courseId=87803904
Focus on the solutions. A public opinion poll by Orsted found that only 66% of people believed climate change was a significant problem; however, 82% believed the world should transition to 100% clean, renewable energy. The reason is because renewable energy reduces costs, creates jobs, gives people pride in their country, and reduces health problems. Many people believe in clean, renewable energy without believing in climate change.@LeadProtagonist asks: As a high school teacher (and not a science teacher, so it's not covered in my curriculum), what are my best ways to address students who deny climate change in my classroom?
That, I can't say exactly, but I would guess that a diet of mostly fruit and vegetables and non-meat protein is best.@Xpike asks: What would the best diet be in order to minimize my carbon footprint?
Geoengineering is not useful or helpful and, in fact, damaging:@Septimus Prime asks: What are your thoughts on geo-engineering?
https://web.stanford.edu/group/efmh/jacobson/Articles/I/GeoengineeringVsWWS.pdf
I can't say. I'm not sure.@StrangerDanger asks: In your opinion, have there been any reliable carbon offset services established with sufficient auditing to be scaled for long-term, validated carbon offsets?
Electricity storage with gravitational masses is one. Underground thermal energy storage is another.@BennyWhatever asks: What are some new, budding green technologies that we should keep an eye out for?
In addition, wind, solar; batteries for storage and electric cars; hydrogen fuel cell vehicles for heavy, long-distance transport; heat pumps (for air and water heating and air cooling) will grow substantially.
Deforestation is a worldwide problem, particularly in the tropics. I can't compare the magnitudes off hand.@Optional Objectives asks: How does the impact of deforestation in Angola and Central Africa compare to what is currently unfolding in the Amazon?
Yes, it will be noticeable but not nearly enough. In addition, it will eliminate 78,000 air pollution deaths per year in the U.S. from air pollution and millions of illnesses per year.@The Archon asks: If the U.S. manages to stop its emissions, but the rest of the world doesn't follow suit, is it enough to slow down climate change in any noticeable way?
I'm not sure.@ZooSteel asks: How do we scale back the unsustainable growth of the human population (without climate change doing it for us)?
I can't answer that.@King Alamat asks: Given the nightmare scenario of a 3°C rise in global temperatures by the end of the century, would Houston even be a viable place to live?
Higher sea levels.@Kyuuji asks: If everything continued at current pace and acceleration with no change, what are some significant climate-related occurrences, events and effects that would be expected/projected to be happening around/by the year 2100 (i.e. what might a snapshot of the world look like should our current rate of progression to address climate change not change by 2100)?
More damaging air pollution (since it gets worse with higher temperature).
More severe hurricanes and weather in general
More droughts/floods, especially coastal flooding.
Large shifts in agriculture
Greater heat-related deaths
More malaria, dengue fever
Greater coral reef loss/ocean acidification
Greater loss in biodiversity
More climate migration
Louisiana, Florida, New York, California, Arizona, Nevada, Texas.@Nothing Loud asks: What U.S. cities or states do you predict in the next 50 years will feel the effects of climate change the worst in terms of dollars of damage and human lives at risk?
I can't say, but it is possible. Sounds like the trees are drier and the winds are stronger. Climate change does create drier vegetation in many places and more severe storms, particularly ocean storms (e.g., hurricanes, tropical storms).@Euphoria asks: Recently on Long Island we have seen storms that last anywhere from 20-30 minutes but caused damage where they rip trees right out of the ground or make them twist and crack all the way up the trunk. Is this a direct cause of climate change? I ask because I'm not really used to seeing this.
NASA has up-to-date temperature data that are reliable:@TheXbox asks: What do you believe is the most credible source for forecasting global warming?
https://climate.nasa.gov/vital-signs/global-temperature/
That's a personal decision that I won't wade into.
I don't know the answer to that.@Woody asks: How many of your fellow colleagues/associates have gotten into survivalist training, off-grid living, bunker-building, etc. since you've been in the field (i.e. are many scientists already prepping for the worst)?
Anywhere that is near the coast and less than 5 m above sea level, at least for the near term.@Mortemis asks: Which parts of the US do you think would be a good idea NOT to buy a home in as the climate changes?
I don't know the answer to that off hand.@Bee.Cups asks: Where's the best place to live to weather the changing climate with little change year to year?
Coal is down to about 28% of US electricity production. I hope all electricity from coal is eliminated by no later than 2030.@Arm Van Dam asks: How long do you think the coal industry can last in the United States considering that the use of coal has been declining for years?
No.@UnholyChocolate asks: Should we just let the Amazon/arctic circle burn?
1) Electrify everything and provide the electricity with clean, renewable energy.@OniLinkPlus asks: What is an action we can push our legislators to take to combat climate change?
2) Use electric heat pumps for air and water heating and air conditioning.
3) Use electric vehicles and hydrogen fuel cell vehicles, where the hydrogen is from electricity.
4) Electrify industry.
5) Reduce energy use.
1) Ban natural gas and other fossil fuels during the new construction of buildings (as Berkeley has done).@jedivulcan asks: What are some improvements to city planning and roadway construction that are practically easy to implement but consistently overlooked or never done?
2) Add a more bike lanes to roads.
A transition to 100% clean, renewable energy worldwide would reduce energy requirements 57% due to the efficiency of electricity over combustion and the elimination of energy to mine/transport/refine fossil fuels and uranium and due to modest end-use efficiency improvements. Thus, a transition would help to get us on a path to consuming less energy.@Rupetta asks: The Anthropocene seems like the logical material conclusion of capitalism and its imperative of compound growth (annual growth of min. 3%). Energy production (green or not) is mainly used for profitable investment opportunities to achieve this compound growth - . In what way would switching to 100% renewable energy or other policies you champion, challenge a "growth of growth" imperative?
Sure. Venus is an example of the runaway greenhouse effect. However, chances are would stop emitting before that happened possibly due to running out of fossil fuels.@Jeb asks: Is there a scenario in which the effects of climate change can lead to the complete extinction of the human species?
Through policies instituted by nations and by individual actions. Since transitioning to renewables reduces costs and creates jobs, countries should be motivated to transition.@Funyarinpa asks: How can developing and less economically developed countries adopt renewable energy resources on a meaningful scale?
Yes, that is the only useful method of removing carbon from the air (reforestation and reducing deforestation).@Cyprinodon Martius asks: Does the process of re-wilding areas with their natural flora and fauna have a worthwhile place in combating climate change?
Hard to tell. I would need to know more. I don't know what the combustion emissions are and how much energy is needed to obtain the iron in the first place or how much is needed. In general, we want to eliminate combustion to eliminate air pollution in addition to eliminating carbon emissions.@UltimusXI asks: At TU/e (University of Eindhoven, The Netherlands), they are building a demonstration system (for an actual customer, not in a lab) where they're burning iron powder as a 'circular / CO2 free' alternative to coal for industry use. Do you think metal fuels can be a viable not-so-distant future solution? Details about it are here.
Maybe. That is one way to try to educate people.@JAGMASK asks: Do you think that it's possible to make the general public more aware about the major impacts on day to day life that a 1.5 degree increase in global temperature can bring? Many people I speak to have no idea how close the societal impacts of global warming are and think that it's not something that will effect humans greatly until a few hundred years.
We should laser focus on the solutions and try to implement them as fast as possible. Then, we can say we did the best we possibly could.@BabyMurloc asks: How should we approach risk management in climate policy (i.e. the risk of extreme but low probability events like, for example, climate sensitivity being larger than expected)?
Learn about the solutions and understand it is possible to solve the problem if we put our mind to it.@MrSaturn99 asks: What's your recommendation for dealing with climate change anxiety?
I know there is a solution if we eliminate 80% of emissions worldwide by 2030 and 100% no later than 2050 (hopefully earlier). We have the technologies to eliminate emissions and the costs are low today.@HueyFreeman asks: I come across many people that feel there is no hope and therefore no point to implementing changes. How do you go about countering nihilism when it comes to climate change action? It seems like this is a major threat.
People in cities will be exposed to more air pollution, which will kill or injure more people.@Cyborg009 asks: How would climate change effect our bodies? We know what the changing temperatures are doing to our environment but what do you think our how bodies would affected?
Some people will be exposed to more extreme heat, and this will kill or injure more people.
Others will be exposed to more severe weather.
I expect the Arctic may be clear of ice within the next 10 years and that will cause positive feedbacks to accelerate warming faster. It is within our power to stop or slow this if we act quickly by implementing laws and personal actions to transition 80% of energy to clean, renewable energy worldwide by 2030 and 100% no later than 2050.@Tracygill asks: What are your thoughts on a blue ocean event happening sooner than expected?
It all depends on cost, and I'm guessing this won't be cost competitive with wind/solar in most places.@Midramble asks: Is hydrothermal generation (i.e. generation from the temperature differential at the sites of hydrothermal vents) practical? Something I've been hobby engineering for years.
Coastal erosion and flooding; more severe weather (including some additional hurricanes and more intense storms). Also hotter summers.@KSweeley asks: I live in Baltimore, Maryland. What exactly will people who live in major cities along the East Coast such as Baltimore observe as the effects of climate change both currently and in the future?
@nelsonroyale asks: How much of a threat to do you think supply chain vulnerability is to rolling out and maintaining renewable technology over the coming years?
Adjustments will be needed but I don' think the supply chain will be hampered too long since there will be financial incentives for everyone to secure the supply chain. Plus, there are many ways to produce different technologies and many different technologies that will be implemented.
Yes, but the pace would be way too slow. For a solution to occur on the timescale that we need it, we need effective policies put in place as well as concerted personal actions.@Foffy asks: Do you believe "market-based solutions" (i.e. the current way we've been doing things) solve this issue [of climate change]?
Grow plants and trees.@davidpoobond asks: What is the most viable form of carbon capture a normal person can do?
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TANGENTIAL QUESTIONS:
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"The climate has been hot before."@Hoodbury asks: What is the dumbest/funniest but still serious response you have heard from a non climate change believer?
Yes, 4.6 billion years ago, the Earth was molten, which is why that time is called the Hadean eon.
And 100 million years ago, the Earth was ice free - but no people lived then. Now we have 7.5 billion, with most people living along coastlines.
1) PNAS itself claimed it was trying to be neutral. PNAS published their paper and our detailed refutation of their claims, thus gave us the last word:@TheLostBigBoss asks: PNSA published a very in-depth rebuke of your recent 100% Renewable study, it included multiple authors from well respected institutions including Stanford (your own academic institution for those who don't know)
Without getting too bogged into the details, how can you argue that 100% renewable is so easily within reach as you have been describing and promoting, while storage solutions on mass scale that are needed to gain 100% renewable are theoretical at best?
http://web.stanford.edu/group/efmh/jacobson/Articles/I/CombiningRenew/PNASReplyClack.pdf
The problem was that PNAS published a paper with false information and did not correct it.
2) Two independent peer-reviewed articles have refuted the Clack et al. paper:
The first one,
https://www.sciencedirect.com/science/article/pii/S1364032118303897
concluded that Clack's and other critiques of 100% contain "factual errors, questionable assumption, important omissions, internal inconsistencies, exaggerations of limitations, and irrelevant arguments."
It goes on to state,
"Of particular concern is that PNAS published the Clack et al. article as a Research Report instead of a Letter to the Editor, although the article contained no original research -- it only criticised a genuine research paper with claims that generally don't stand up to examination."
and
"Our assessment is that Jacobson et al. have clearly refuted all but one of Clack et al. error claims. However, this is a minor 'error.'"
The second paper that debunks the Clack et al. paper and other critiques of 100% renewables is
https://www.sciencedirect.com/science/article/pii/S1364032118303307
which states, "As a result, we conclude that the 100% renewable energy scenarios proposed in the literature are not just feasible, but also viable."
3) The main conclusions of the Clack et al. paper were derived from their own errors, not from any error in our PNAS paper. For example, they pretended our Table 1 contained maximum values when they were fully informed and aware it contained average values. They used their own error to then claim we make modeling errors when it was their own mistake that produced this claim:
http://http://web.stanford.edu/group/efmh/jacobson/Articles/I/CombiningRenew/18-02-Correction.pdfobson/Articles/I/CombiningRenew/18-02-Correction.pdf
4) Three authors on the Clack paper (Sweeney, Weyant, Victor) are being paid by Trump to fight climate action
http://blogs2.law.columbia.edu/clim...nts/2018/20181015_docket-615-cv-1517_na-1.pdf
Two others (Caldeira, Qvist) wrote plans for the world to go all nuclear:
https://www.theguardian.com/environ...he-only-viable-path-forward-on-climate-change
https://www.nytimes.com/2019/02/05/...uture-joshua-s-goldstein-staffan-a-qvist.html
Others have research interests in technologies (e.g., natural gas, carbon capture) we do not include. These facts all speak to their motivation.
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In sum, I and many others disagree with the premise of the question, that 100% renewables is not within reach. In fact, 8 countries are at 95-100% renewable electricity (not all energy) and 61 countries have commitments for 100%.
There are many ways to get to 100% WWS and storage (electricity, heat, cold, hydrogen storage) in all energy sectors at low cost.
http://web.stanford.edu/group/efmh/jacobson/Articles/I/CombiningRenew/WorldGridIntegration.pdf
I haven't read it.@firehawk12 asks: What do you think of David Wallace-Wells' book?
Not sure which process is being referred to.
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There has been no retraction whatsoever of the technical or economic feasibility of our 100% plan, either in PNAS or elsewhere.@Copper posted: Jacobson has been widely criticized for his absurdly handwaving projections that basically underestimated the factor of hydro needed to run full renewables by a factor of 2 or 3. In fact, he had to retract on several of his initial statements over the feasibility of his 100% renewables Plan. A group of climate and Energy scientists had to write a collective letter to him about this, to which he firstly responded by calling them shills of the Fossil industry.
There have been much more realistic 100% plans then the Jacobson One (i don't remember names now, but in short double overgen, 20% baseload and a day of storage is what you need in most scenarios, Jacobson was nowhere close to it). In fact, i'd be wary of anything this man put out After the precedents.
Further, there was no error in our hydro calculations for the PNAS paper, only misrepresentation by the Clack et al. authors about what was done :
http://web.stanford.edu/group/efmh/jacobson/Articles/I/CombiningRenew/18-02-Correction.pdf
To the contrary, the idea of uprating hydro plants (increasing their nameplate capacity without increasing annual average power output) in order to help meet peaks in demand was a novel idea, which helped to earn the PNAS paper the Cozarelli Prize from PNAS. The U.S. Bureau of Reclamation
https://www.usbr.gov/power/edu/pamphlet.pdf
states that "uprating of existing hydro generator and turbine units is one of the most immediate, cost-effective, and environmentally acceptable means of developing additional electric power. Since 1978,..uprating added more than 1,600,000 kW at avg cost $69 per kW"
Whether hydro plants can be uprated to the level proposed in the paper is a social and political question, not a technical or even economic question See, for example, the calculated costs of such uprating here:
http://web.stanford.edu/group/efmh/jacobson/Articles/I/CombiningRenew/Clarification-PNAS15.pdf
In fact, it is much easier to do what we proposed than to implement the proposed schemes by two Clack authors (Caldeira and Qvist) who want to move the world almost entirely to nuclear power
https://www.theguardian.com/environ...he-only-viable-path-forward-on-climate-change
https://www.nytimes.com/2019/02/05/...uture-joshua-s-goldstein-staffan-a-qvist.html
or the scheme of Clack to convert the US entirely to HVDC transmission without any storage whatsoever.
https://www.nature.com/articles/nclimate2921
It was hypocritical for these authors, the only ones that claimed to perform work on a 21-author paper, to criticize a potential plan without criticizing their own even-more-difficult-to-implement plans.
There are at least 42 peer-reviewed papers supporting 100% renewables
http://web.stanford.edu/group/efmh/jacobson/Articles/I/CombiningRenew/100PercentPaperAbstracts.pdf
and independent peer-reviewed papers find 100% feasible.
https://www.sciencedirect.com/science/article/pii/S1364032118303897
https://www.sciencedirect.com/science/article/pii/S1364032118303307
so the claim that more realistic plans than 100% renewable is not substantiated.
The idea of uprating hydro plants (increasing their nameplate capacity without annual average power output) in order to help meet peaks in demand was a novel idea, which helped to earn the PNAS paper the Cozarelli Prize from PNAS. The U.S. Bureau of Reclamation@TheLostBigBoss posted: ....The most glaring of which is the assumption that U.S. hydroelectric dams could add turbines and transformers to produce 1,300 gigawatts of electricity instantaneously — equivalent to over 16 times the current U.S. hydroelectric capacity of 80 gigawatts. A previous study by the U.S. Department of Energy found the maximum capacity that could be added is just 12 gigawatts — leaving a 1,288 gigawatt deficit, or the equivalent of about 1000 large nuclear or coal power plants running at full power.
https://www.usbr.gov/power/edu/pamphlet.pdf
states that "uprating of existing hydro generator and turbine units is one of the most immediate, cost-effective, and environmentally acceptable means of developing additional electric power. Since 1978,..uprating added more than 1,600,000 kW at avg cost $69 per kW"
Whether hydro plants can be uprated to the level proposed in the paper is a social and political question, not a technical or even economic question. In fact, it is much easier to do what we proposed than to implement the proposed schemes by two Clack authors (Caldeira and Qvist) who want to move the world almost entirely to nuclear power or the scheme of Clack to convert the US entirely to HVDC transmission without any storage whatsoever. It was hypocritical for these authors, the only ones that claimed to perform work on a 21-author paper, to criticize a potential plan without criticizing their own even-more-difficult-to-implement plans.
The 12 GW being referred to has nothing to do with uprating existing hydro plants. It has to do with powering non-powered dams.
All nuclear plants ever built have had a planning-to-operation time of 10-19 years, so you're just illustrating why the Clack paper was flawed. The lower limit of nuclear war emission was zero, which the Clack authors failed to report. The higher emissions due to the time-lag between planning and operation of nuclear causes mortality, and this is a fact.@Steel posted: I'd say that's not even the most glaring assumption, there are quite a lot, such as:
"As an example, the lifecycle GHG emissions for nuclear power generation in ref. 21 include the emissions of the background fossil-based power system during an assumed planning and construction period for up to 19 y per nuclear plant.7 Added to these emissions, the effects of a nuclear war, which is assumed to periodically reoccur on a 30-y cycle, are included in the analysis of emissions and mortality of civilian nuclear power.8"
https://web.stanford.edu/group/efmh/jacobson/Articles/I/NuclearVsWWS.pdf
Aviation is already starting to be converted to hydrogen. The electricity analogy is misplaced since a WWS system converts all energy to electricity so electricity demand goes up by a factor of 2-3 but all energy goes down 50%.Or this bit:
"The 100% wind, solar, and hydroelectric power system study (11) also makes unsupported assumptions about widespread adoption of hydrogen as an energy carrier, including the conversion of the aviation and steel industries to hydrogen and the ability to store in hydrogen an amount of energy equivalent to more than 1 month of current US electricity consumption. Furthermore, in figure S6 of ref. 11, hydrogen is being produced at a peak rate consuming nearly 2,000 GW of electricity, nearly twice the current US electricity-generating capacity."
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And that concludes the Q&A!
I would again like to thank Professor Jacobson for his time, as well as all of the users who submitted their questions. It is my hope that through this exchange, we all will have learned something valuable and do everything that we can to combat climate change in a way that causes the least amount of harm.
Thank you, everyone!
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