Last week I did my 9^th Ask Me Anything on Reddit. AMAs are always fun—they really live up to the name. Redditors asked about climate change (including my new book on the subject), COVID-19, advice for a young software engineer, taxing the wealthy, conspiracy theories, the books I’ve been reading, and lots more. I even got in a plug for my favorite comedy of all time.

You can see all the questions and answers below. Thanks to everyone who joined the AMA. I can’t wait for the next one!

Redditor’s question: Hi Bill! How are you doing today?

My answer: Great! I like typing...

Hi Bill, Firstly, thank you for doing this AMA! At what percentage would you say our chances of reaching (net-) 0 emissions by ~2060 are at today?

It really depends on whether the younger generation worldwide adopts this as a moral cause they force us to pay attention to. If they do then I would say 75% chance of success. If there isn't that push then the investments may not get made. Innovation is hard to schedule but with lots of inventors some will succeed. We are seeing a lot of amazing companies which Breakthrough Energy Ventures is funding. Now we need to create the demand and scaling of the successful products including in hard areas like steel and cement. Governments are engaged because they see the voters caring more and this year will have some key events like Glasgow (COP26).

What's the best scenario if we do nothing about climate change?

It gets worse over time and natural ecosystems go away. The migration away from the unlivable areas around the equator will be massive. We won't be able to support a large population if it gets a lot warmer.

Thanks for doing this AMA! What do you think are the most important things that regular citizens can do to decrease their carbon footprint?

Your political voice is the most important thing. Getting educated and convincing people of all political parties to care will make a huge difference. Then you can consume less and when you do consume buy green products like electric cars or synthetic meat. You will also be able to give to a fund to help with this. Another area is to make sure your company is paying for offsets and doing its part. If you want to help, there are ways everyone can get involved.

What are you personally doing to consume less?

I created Breakthrough Energy including the Venture fund, Fellows and Catalyst to help with climate. To me the innovation is what will make it possible to provide services to everyone without emissions.

On the personal front, I am doing a lot more. I am driving electric cars. I have solar panels at my house. I eat synthetic meat (some of the time!). I buy green aviation fuel. I pay for direct air capture by Climeworks. I help finance electric heat pumps in low cost housing to replace natural gas. I plan to fly a lot less now that the pandemic has shown we can get by with less trips.

What niche technology do you believe could play a significant role in the future in the battle against climate change?

We need a lot of technologies - synthetic meat, energy storage, new way of making building materials,...We want to be open to ideas that seem wild. Fusion might come along but we can't count on it.

When Oxford University was working on a COVID-19 vaccine it announced that it would be made "open source", meaning that any pharmaceutical manufacturer would be able to produce it legally without infringement on any drug patent, which would make the vaccine more widely available and less expensive, enabling widespread vaccination of the economically destitute populations in developing countries. But after their announcement that they would make the vaccine free to produce, they received immense pressure from the Bill and Melinda Gates Foundation (wherein Oxford research staff were threatened with the reduction or elimination of all grants from the Foundation, not limited only to those for medical research) to patent the vaccine and partner with AstraZeneca to sell it. So, now, not only did AstraZeneca receive all the accolades for "developing" a vaccine (which the company did not do), it's also being produced in limited quantities and sold for $4 per dose to the federal government, which is about 20 times more expensive than the estimated cost if the formula had been open source and allowed to be mass produced by any manufacturer with the required equipment. In addition, because it is patented, it can only be produced by AstraZeneca, and poor countries have no or limited access to inexpensive vaccines. Why did you do that, Bill?

Our foundation has given over $2B to help with this pandemic. I value anyone looking at what we have done and giving us suggestions. The problem with vaccine manufacturing quickly is not an IP problem. We sent funds to Serum Institute and others early in the pandemic because of the lead time for factories including regulatory review to make sure the factory is high quality.

This vaccine is inexpensive - around $3 to $2 once you get into high high volume but there are fixed costs to get going.

[EDIT: After I posted this answer, a Redditor helpfully posted a link to this interview, in which I give a more expansive response to this question.]

Hey Bill, I will be doing my first internship this Summer as a Software Engineer for a well known bank. I am a little nervous and really want to perform well. As a successful figure in the tech industry, do you have advice or insight for a young intern going into the tech industry? Thanks in advance and thank you for all the good you have done in the world.

You can surprise people by learning a lot about the company and its competition and its systems. If you are helpful and friendly you will likely get good mentorship from the experienced employees. I think you can be open about your nervousness and a reasonable company will embrace your honesty.

Is it possible to stop global warming without decreasing of the population growth number?

Fortunately population growth stops when countries improve health and get to middle income levels. Population will peak around 10B if we are generous to the poorest countries particularly in Africa. Africa faces climate problems and population growth so having enough food and education and stability is a huge challenge. It was looking at African agriculture and how the climate is making it less productive that got me to study climate. So we should help moderate population growth with aid for health, education and good governance.

The best book on this is Hans Rosling's Factfulness.

10B is a lot especially as they consume more so the imperative for innovation in seeds and green approaches with low premiums is urgent.

Favorite Mortal Kombat fighter?

I have never played.

Hi Bill, What do you think is a reasonable percentage tax rate for the extremely-wealthy to pay? Either on their income, gains, or total wealth.

Taxes are an important issue. Government has to do more - health costs, pandemic recovery, climate investments, foreign aid generosity... So I have pushed for some higher taxes. I have disagreed with some proposals that seem to go too far.

I have pushed for the Estate tax to be higher. I think it is an effective tool for revenue and avoiding dynastic wealth. I have a piece on Gates Notes that talks about more progressive taxation.

You can tax income up to 50% but once you get much above that you have to worry that people waste a lot of time getting around the taxes. Each country has to consider what works for them. I only know the US system and it can be somewhat more progressive.

Are you familiar with Bjorn Lomborg's works, of so what do you think about his book False Alarm, and the idea that Climate Change, even though its a very serious problem we should solve, isn't the one we should prioritize?

Bjorn focuses on the need to innovate but he is far too narrow. He doesn't appreciate the need for demand for green products to scale up these markets. I enjoy talking to Bjorn - he has done a lot of good work but climate needs a lot more investment and policy work than he suggests.

What is your favorite comedy film?

Obscure film - Its a Mad Mad Mad Mad World…

Why can't we read your book How to Avoid a Climate Disaster for free?

We are working on a way for college students to get free access digitally.

How does it feel to know that a creation of yours - windows - completely changed the world?

I am proud of Microsoft and the work we did on great software and helping the Digital revolution. It was fun to be part of it. I actually enjoy my current work on Global Health just as much but it is different.

Hello Mr. Gates! I am curious about this: How do you cope with hate, theories and conspiracies about you? Thanks for doing this!

I get both positive and negative feedback for my work. Intelligent criticism is helpful. If people have ideas about how to solve climate that are different from mine or better solutions for global health I want to hear about them. Just personal attacks don't move things forward as much but I don't let it stop me.

Hey Bill, How does it make you feel when you see these conspiracy theorists talking about how you are plotting to take over with the Covid-19 vaccine? Also, GME?

Vaccines are important and it is too bad they are so controversial. I don't know why people think I want to track other people - it is unfortunate if this makes people not wear masks or consider getting the vaccine.

Hi Mr. Gates, I am a 16 year old at Wilson HS in Long Beach, California. My passion is education and I know that many students can share this desire, but it is hidden beneath distractions and social norms for so many people around the world. My school has a majority low-income and 81% minority enrollment and we have been doing remote learning since a year from this date. During this time, I decided to start a non-profit online platform that focuses on increasing the motivation and confidence that students have for education, keeping in mind the fact that students learn differently even among similar areas, cultures, and backgrounds. My goal with the platform is to be a place where students create their own instructional videos, which solidifies their learning and gives them motivation associated with the satisfaction that comes with creating the end-product of a video. The result is that students learn from teaching, also known as the protege effect, and gain opportunities to practice their presentation and technical skills in a world that embraces video presentation skills. On the platform, students can also learn from each other by interacting with the videos of their peers from around the world. I know that it is an ambitious and not mainstream concept to have students teach and make videos, but after personal experience and research that backs it up, I have conviction that this can improve motivation and outcomes for all students. To help foster the growth of this concept, and to make it mainstream, I plan to raise funds to hold quarterly scholarship competitions to encourage more participation in this opportunity throughout the world. What advice can you give me about my mission to introduce this idea to the mainstream of education?

I think people connecting across country boundaries is important. We should understand the perspective of the young generation in China, Nigeria, India, etc. If we can use digital tools to connect like this that would be great. I also think on-line learning can improve a lot so it is great you are working on that.

Hello Mr. Gates! Do you still code on your computer? If so, how often? If not, have you gotten rusty? Thanks!

My code no longer goes into shipping products so I am rusty. I do like to try the new tools to understand how they help. I just did a review of the low-code tools where there is a lot of great innovation.

Best burger in Seattle?

I am eclectic. Dicks, Burgermaster, etc. Seattle has a lot of good choices. I encourage people to offer synthetic beef as a choice.

Any comment on the opinions of r/conspiracy about you and vaccines?

I am innocent! The whole thing about 5G and microchips is pretty crazy. Why would I want to do that? I do believe in vaccines which have performed miracles. My 2015 Ted talk was more viewed after the pandemic than before which is too bad. I hope my 2010 Ted Climate talk is viewed more before the problem gets bad…

What book have you most recently read?

Barack Obama's autobiography is good. Overstory is a great fiction book a friend got me to read. I just read Hot Seat about Jeff Immelt running GE. I am starting a Jeff Hawkins book called A Thousand Brains. Next will be Daniel Yergin's The New Map.

What is your opinion on "engineering" a solution for the climate change problem? Economist Stephen Levitt has written on this topic [1], [2], [3], and has even bet that geoengineering is pretty much the only solution that will get us towards the goal of cooling the Earth by about 2°C pre-industrial levels [4] in time, before catastrophic, irreversible changes. On a similar note, what is your opinion on large scale carbon sequestration projects and carbon offsets that corporations purchase? Stripe has a Climate division now that lets customers divert a fraction of their dollars to purchase carbon offsets [5]. Do you think such efforts are important in preventing large scale climate change and what are your views on it?

Also, did Vaclav get a chance to read this book? What did he think of it? Thank you again for doing this AMA!

Direct Air Capture will be important for things we can't solve directly. Today the cost is over $600 per ton. I think it can come down to $100 with companies like Carbon Engineering as they scale up over the next decade. We don't know if we can get it cheaper than that.

Companies that are buying offsets are fantastic. We need to work on rating different offset on how impactful they are. I even am putting together something called Catalyst which will direct offset money from companies to getting green products to be less expensive. Geoengineering should be explored but only as a backup.

Hi Bill, It's well established that you bring a large tote bag of books on trips and usually finish them all prior to returning home. How are you able to focus and absorb so much information, especially when (I assume) the main purpose of these trips isn't usually reading? Is there a specific note-taking strategy you use? What exactly do you write as you're taking notes? I've been trying to read more during the pandemic and sort of succeeding, but at times I find myself looking at words and not absorbing their content. This is partially due to ADHD, but I think learning to take notes will help. Thank you!

On vacation I get to read about 3 hours a day so I get through a lot of books. I only take notes on about 20% of the books I read. It takes me at least 2x as much time when I write notes but for a lot of books that is key to my learning.

Hey Bill! How do you think Seawater Desalination will impact the issue of global water shortage in the coming years?

Yes. We have lots of water. The problem is that it is expensive to desalinate it and move it to where it is needed. This is all about the cost of energy. The cost is prohibitive for agricultural use of water. New seeds can reduce water use but some areas won't be able to farm as much.

How do you think the PR-problem of nuclear energy can be solved?

I hope so. Nuclear has had real cost problems as the systems have gotten more complex. A new generation that starts over and gets rid of the high pressure is needed. Explaining how the new safety systems work will be very important. The actual record of nuclear isn't bad compared to coal or natural gas but we can do better with the new design which can be inherently safe.

I live in a mid sized city in Canada (Winnipeg). What are the most effective things I can get my local government to do that will have a positive impact on climate change while being cash positive or having a tiny green premium?

Electric buses are becoming economic. There has been an issue with cold and hot temperatures but that is being solved as the demand scales up.

Cities are often involved in electricity generation so they can help drive demand for clean generation.

Hello Mr. Gates! How long did it take you to write your new book (including researching, interviewing, and the general writing process)? Thanks for taking the time to do this!

I had a lot of help from my staff including Josh Daniel and I was able to draw on all of my learning about climate from over a decade. I would say it was 2 months of full time work spread over a year including a big edit this last November.

What one piece of advice you would give to a 19 year old?

You should learn about climate change. It doesn't need to be a full time thing - you should pick the job you care about and feel you can contribute to but also have goals that aren't just about your own success.

How misinformation, disinformation, and fake news can do damage to society?

This is a huge issue. Some false information is more interesting than the truth so digital channels seem to magnify echo chambers with bad facts. I haven't seen as much creativity on how we solve this as we need.

Hello Mr. Gates! What is something alarming about Climate Change that most people don’t know about? (something that was not included in your new book). Thanks for doing this; it made my day!

I didn't spend time going through all the bad things climate will do if we don't solve it. However the list is very long and some things could accelerate as we heat up. The damage to nature is going to be massive. David Attenborough has a movie that isn't really about climate but more about the beauty of nature and what we are losing that is very good.

Do you think lab grown meat will become widespread and replace livestock? Do you have experience with lab grown meat?

If the cost of making synthetic meat comes down it might be competitive even without considering climate or animal welfare. There are two approaches - one is growing the meat in the lab (cells), the other is using plant material to make the meat. Right now the plant approach used by Beyond and Impossible is cheaper.

I hope we can reduce emissions from cattle also since a lot of people depend on the value of their livestock. There is some research on this.

Will climate change make future pandemics more common or more severe and how?

I wouldn't tie them directly. Pandemic risk is hard to compute but with humans invading nature more and more it has gone up. Travel causes fast spread which makes respiratory diseases very scary. We can prepare for the next pandemic with tens of billions in investments. I will be talking about this more this year to make sure we do the right things while people still remember how bad this pandemic was.

Hi Bill, How do you think misinformation plays a role in difficulting the battle against climate change? Do you think it has a meaningful impact or is it minimal?

The damage in the past was huge. Now the oil companies have stopped funding these things so I think climate denial will go down. There are issues about how we go about reducing emissions but I hope all young people agree that is a critical goal.

Do you see UBI as a sustainable way of economic?

Today we provide income to people who are disabled in many countries. The question is can we afford to do this for everyone. We are getting richer as we innovate but I question if we are rich enough to discourage able people from working. Over time we have been more generous and we will be more generous. The discussion on this is very interesting but it does come down to numbers…

Hello Mr Gates, do you think crypto mining should be banned globally due to the energy costs involved? Edit : expanding on this, they contribute significantly on pure energy, let alone the carbon footprint of computer chips that are used to mine currencies. They seem to be easiest to remove carbon emissions because they hardly serve value apart from investment. Single transaction costs 700-800 kWh and that's just not acceptable.

I have a lot of issues with anonymous money transfer compared to attributed systems where you can dispute and reverse transactions and make sure taxes are paid. The electricity use is just one issue. We do need digital money but without that overhead.

Hey Bill! Why are you buying so much farmland?

My investment group chose to do this. It is not connected to climate. The agriculture sector is important. With more productive seeds we can avoid deforestation and help Africa deal with the climate difficulty they already face. It is unclear how cheap biofuels can be but if they are cheap it can solve the aviation and truck emissions.

While going vegan might seem to be a huge stretch for some, it's important to know that 1/5 of the CO2 reduction goal can be met by changing our eating habits! Think about it, by reducing our meat consumption as much as possible (i.e. going vegan or limiting it to 1-2 meals per week and by meal, I mean the meat should not be more than 1/4 of our plate), we can help reach neutral carbon! Source : IPCC report from 2018 on limiting global warming to 1.5C° (I don't remember the exact chapter, and I don't have access to it at the moment. That said, if someone is interested, I should be able to quickly find it back once I am home)

Go vegan!

Yes. Meat is responsible for a lot of emissions but I think people will still want meat so alternatives are key.