Climate change. Nuclear war. Asteroid Collision. Supervolcanoes. 

For TIME Magazine’s former Senior Writer, Bryan Walsh, these are among the numerous catastrophes threatening civilization.

Walsh’s latest book, “End Times: A Brief Guide to the End of the World (Hachette Books, 416 pp.),” publishes on Aug. 27. It examines the biggest natural and man-made threats to civilization, their impact and how to prevent and prepare for them.

In Karma’s conversation with the 15-year veteran science reporter, Walsh discussed pressing issues such as nuclear war and disasters that may affect climate change. He warned that investors should be alert to “a more dangerous world than ever before.”

Keshav Pandya: What was your goal when writing this book? What do you hope to show?

Bryan Walsh: Whether it is a big catastrophe like an asteroid hitting the Earth’s surface or an ongoing thing like climate change or stuff coming from emerging technologies like AI or biotech, I look into something called existential risks. I researched each of these individually, talking to a lot of experts in the field, gathered researched around them, and created a journalistic guide to what seemed to be the most pressing issues from natural ones to human-being induced ones. We are in a more dangerous world than ever before, and yet we also have the ability to respond to these issues and prevent the worst from happening.

Pandya: You talk a lot about climate change threats in the book. What were the major issues that emerged  in your reporting and research?

Walsh: Climate change is different from other risks in the book. For example, an asteroid either hits earth or it doesn’t. Nuclear war either happens or it doesn’t. With climate change, it is happening now and has been happening. It is killing people already. It’s gonna keep getting worse, considering we’ve been putting a lot more carbon in the atmosphere. What we do will have an impact on people 50-60 years from now. The question I was looking into was at what point can climate change end humanity, versus something that can go really wrong like a nuclear bomb? How bad it gets depends on how we respond to it, what policies we put in place, and what type of technologies we use to take carbon out of the atmosphere. But there’s always a possibility that we don’t do anything or aren’t good at removing carbon, and face tipping points. 

Pandya: What do you say is the tipping point here?

Walsh: It’s all murky. Scientists use an increase by 3.6 degrees Fahrenheit (above pre-Industrial levels) as the red line. Leading up to that, you see intense events. We raise the risk of things going really bad. Ultimately how we deal with it is dependent on what we do politically and technologically, more than what scientists do. 

Pandya: You touch on different apocalyptic scenarios. Did you feel like you touched on too many and didn’t hone in on a couple? 

Walsh: The subtitle was a brief guide to the end of the world, and it didn’t end up being as brief as I thought it would be. At the same time, it’s hard to pack everything you need to know about each one of these subject matters, like climate change.  So I tried to highlight which aspect of each risk showed the whole issue. For something like climate change – instead of presenting all that I know about climate change, I decided to focus on what aspects of climate change really make us think about the future.

Pandya: For any of these issues, do you give examples from your reporting and experiences traveling?

Walsh:  For climate change, I talked about traveling to the Greenland icecap in 2008 and seeing glaciers melting and moving into the ocean. Or, with pandemics and disease, I was on the ground reporting in 2009 during the H1N1 flu epidemic. It was a mix of reading and research, talking to experts around it, and also going out there on the field.

Pandya: How should we consider nuclear war in terms of climate change?

Walsh: So there was a potential nuclear war and a shift when the Cold War happened in 1945. Now we have a number of ways these wars could happen via biotechnology. But nuclear was the first of its kind. I look through how people reacted to nuclear weapons during that time, then the risk of nuclear war during the Cold War, and then today where the risk is back. We see the U.S. and Russia developing more nuclear weapons and tests. You see new countries with nuclear weapons. Climate change is front and center, with good reason. But if something were to end the world tomorrow, the most likely one would be a nuclear war. There needs to be a push for countries to reduce that risk. 

Pandya: What experiences have convinced you that nuclear war is possible? 

Walsh: I was a foreign correspondent in Tokyo, when North Korea exploded its first nuclear test in 2006. Then it was also talking to people like Daniel Ellsberg, best known for releasing the Pentagon Papers, who also saw the nuclear testing in the 1960s, and has been concerned and pressed against it since then. When people like him warn us about nuclear warfare, it says a lot.

Pandya: Who would you say your audience was in this book?

Walsh: It’s the future of humanity so it can be anybody. There’s nothing more important than this subject matter of what can happen in our future. If you are concerned and working against things like climate change, and people into emerging technologies like AI, they can get a lot out of this. If you are interested in investing in positive trends and businesses, and how they will have a big impact for our future, I speak on that as well. Investors should look into innovative artificial intelligence and biotechnologies that can help us progress in a positive direction. 

Pandya: Were there organizations or people that are doing interesting and important things to solve or prevent these issues?

Walsh: One subject that came up was the concern for food, meaning, how do you ensure that in the event of any number of risks that would have a big impact on the climate, you can prepare food for survivors. 

If a major super volcano goes off or a nuclear winter, it would cloud the sky and vastly reduce sunlight. It would be lots of cooling fast. That would reduce farming. We would run out of food fast. There are people trying to work on food alternatively without sunlight. Which means growing mushrooms or eating insects or growing bacteria, for example. 

There’s a guy named David Denckenberger, at the University of Alaska, who is the leading expert in this field of alternative food. He created a nonprofit called ALLFED, which tries to raise money to raise awareness about the problem and also experiment with different technologies. 

Lastly, there are a number of people in Silicon Valley getting into space exploration too and finding alternative ways for food development.