And how do we reconcile the data with the very alarming news stories from France and from Portugal and Spain earlier this year?

Yeah, and I think this is the challenge that people often have, is that we are primed to focus in on the particular stories of the particular countries that are in the news, and they're in the news because they're having a very, very bad wildfire year.

And there are some countries in Europe where it has been genuinely extremely bad.

So France is a very good example.

Belgium, which usually doesn't get very many wildfires, has a very, very bad year.

At the same time, there are also countries in Europe that have had a really low year.

Like Greece will often have very extreme wildfires.

Can we do the opposite and zoom out? Do we have any data on the global picture for wildfires?

Right.

And then once you get into the kind of 1990s, early 2000s, there were a couple of countries that invested in rolling out solar programs when it was very expensive, right? And just the reality was several decades ago, solar power was expensive.

Right.

But then you get on this train where China gets involved and a couple of other countries get involved.

And then this technology starts to follow what you call a learning curve, where the more of the stuff that's deployed, you start, again, it's this incremental progress.

There were no huge step changes in the price here.

Right.

Okay.

What does the average person get wrong? What does the media get wrong about where we actually are with respect to climate change?

I think a f- a couple of key things.

I think the world has set these ambitious climate targets.

You might have heard of the one-and-a-half degree target or the two degree target, and that's basically targets the world has set on what we're gonna limit temperature rise to.

And we're very rapidly approaching one and a half degrees of warming.

We will pass that.

There's no way that we're gonna stay below that.

Batteries, I mean, they're quite frankly, it just seems like they're moving to where the puck is headed.

It's used for lots of different interventions and projects around the world.

The best analysis we found was from researchers called Charles Kenny and Justin Sandefur from the Centre for Global Development.

What they frame as their preferred estimate was that in recent years, US aid has saved around 3.3 million lives per year.

But what they stress in those estimates is that that ranges from a kind of lower estimate of 2.3 to 5.6, right? So more than a twofold difference.

And I think there are a couple of key reasons why it's really quite hard to estimate this.

First is that they focus very much on these health programs.

HIV, malaria, vaccine delivery.

So how do you disentangle which improvements were actually caused by USAD? They tried to

What do you think is going on and how can people get out of that funk?

Yeah, I think there are two attitudes there.

The first is this kind of blanket, no one cares, right? Which the data very strongly suggests in every country in the world, that's just not true.

In every country in the world that's been surveyed, and that's a large number, the majority of people believe in climate change, care about climate change, are concerned and want to see governments and other policy makers make effort to take climate action.

So the notion that just no one cares is just not true.

The majority of people do care.

And the second thing that people always bring up is this polarisation issue, where often it's framed as people on the left care about climate, but people on the right do not care about climate.

And you want to share how you suggest that we deal with it?

Yeah.

And Ch- and that's because China is the largest emitter.

And, and I think, I think the first question there is really, really crucial.

I think many people in what we might call small-emitting countries feel that way and feel like what they do doesn't matter, or what their, their country as a whole does or doesn't do doesn't matter, and I think that's just simply incorrect.

And as I try to put forward, um, in the book, if you were to take the world's CO2 emissions, uh, kind of as a pie, right? So China is around a third of the total, right? So it's very, very clear, if China doesn't take action on climate change, we won't be able to solve climate change.

There's another third which is made up of countries that we would say have, you know, reasonably high emissions in terms of the global total.

So let's say they have more than 2% of the total, so that's another third.

What do you mean by that?

And so what were the results then? And did they surprise you?

Yes and no.

So the results, the actual number of the carbon footprint, which was an average of the nine farms.

So we're being careful to say it's not an average of New Zealand pork.

It's an average of the nine farms that participated.

It was 5.8 kilograms of corn.

carbon equivalent per kilogram of pork produced.

Do you know how that benchmarks across, say, lamb or beef? Have you done those comparisons?

And it's that supply which has contributed to the United States, the UK, and then the rest of the world becoming heavier and heavier.

Probably over the last 30 or 40 years, you've seen, um, the most substantial rise.

So if we go back to kind of 1980, um, obesity was already a problem in today's rich countries, right? So they already had relatively high rates of people being overweight or obese.

I think what's really changed over the last 30 years or so has been this shift to it not just being a rich country problem to being a truly global problem.

So you've actually seen quite rapid rises in obesity levels in low- and middle-income countries, which you hadn't seen previously.

Just to give a bit of context there, so in 1980, around one in five adults were overweight.

Today that's clos- closing in on half globally.

Other maps on the Our World in Data website show the impact of obesity, including its contribution to death rates.

So in rich countries, LEDs have actually reduced energy consumption by 50%, despite us sticking millions of them anywhere we can possibly think of

And the story in other economies, so low to middle income countries, has been not that they have cut the amount of energy used for lighting, but that basically LEDs have curbed the increase that would have happened if they'd purely been using incandescent light bulbs, right? So what you've seen over the last decade or so is actually hundreds of millions, if not billions of people, rising incomes, moving out of energy poverty, maybe getting their first artificial lights for the first time, right? So they are consuming more electricity for lighting, which is why you generally saw an increase, but that has been curbed by the adoption of LEDs, so you haven't had as much of a rise as you otherwise would have

What LEDs have achieved is actually pretty unique.

Other technologies have also seen efficiency gains, but I don't think to the same extent as lighting, right? So fridges and air conditioners and other electronic appliances have got more efficient, but not to the extent where they are five to ten times more efficient like you've seen with LEDs.

If you look at the increase in electricity consumption for other sectors, they've actually been still been growing very, very strongly, partly because you have people moving out of energy poverty.

Is there an example of something in the past, Hannah, that you said that you now think that you would revise if you were going back to re-say or rewrite it?

There's definitely, uh, I think there's things that I've been wrong about, and then there's stuff...

There's always when you're writing a book or doing any form of writing, you have to make choices about what you include and what you don't include, right? And you have constrained space.

I think one thing from my first book, Not the End of the World, that I would have added, and I think was, like, useful kind of criticism from, from some people is w- is this tension between the environmental impacts of meat and the kind of animal suffering lens of it, right? And maybe we'll get into this, but, like, when it comes to environmental impact, for someone that's going to eat meat, right, often the best option for the environment is chicken or fish, right? They tend to have a lower carbon footprint than beef or pork or dairy, right? And that's the kind of recommendation I give.

You know, if you are going to eat meat, that's the probably the more environmentally sustainable choice.

Uh, what I didn't really cover in much detail there is that it's probably the opposite for animal welfare, right? So if you're eating chicken and fish, you're naturally killing more animals in order to provide that meat 'cause they're smaller, and often the living conditions of those animals are worse, right? So I think looking back on my first book, I w- I wish I'd had more of that kind of animal welfare, environmental impact balance in there somewhere.

And then, like, stuff that I've just changed my mind on or just outright wrong on, uh, I mean, I think I've been...

Is there something that you think is still needed right now that you hope that somebody listening may think, "Oh, yeah, I would start a company to try to solve that problem"?

And it's not just cats that are more deadly for birds than wind turbines.

Buildings and cars and trucks are, are also very high on that list, so they kill maybe 600 million for buildings and around 200 million for cars and trucks.

There are other big hazards like pesticides, communication towers.

They are kind of in the, the order of magnitude of, uh, millions to tens of millions, and obviously these hazards just don't get the same attention in terms of policy, uh, uh, and media attention as wind turbines do.

So I think the number is maybe correct, but I think the context surrounding it is missing to help us understand whether this should be a barrier to us deploying wind power or not.

So what's the final verdict? Should the number of birds being killed make us reconsider our use of wind turbines?

I don't think the death toll from wind turbines should stop us from deploying wind power for a couple of reasons.

I think the first one is that we are actually deploying clean energy for a reason, and, and, and part of that reason is to mitigate climate change and also it has the side benefit of mitigation air pollution, and both of those are relatively large threats to birds and, and wildlife at large.

Every couple of years, the UN publishes global population estimates, and using historical estimates of population and fertility rates, the age structure of the population, and indicators such as life expectancy, the UN makes forecasts as to when the world's population will peak.

If we start with its 2019 publication, it was basically saying the global population in its medium scenario would reach 10.9 billion people by 2100, but actually that wouldn't be the peak yet, so the population would continue growing past 2100.

If we take that forward to its 2022 publication, so at this point, it was saying that the peak would be in 2086.

Two years later in its 2024 publication, it brought this forward two years again to 2084 as its predicted peak.

Looking back at previous forecasts-

Often, the actual estimated fertility rates have actually been more closely following what we call the, the low scenario in their, the projections historically.

So basically, fertility rates have been falling faster than they might have expected.

I think another key uncertainty is around the fall in fertility rates across Sub-Saharan Africa.

How do you think about our agency at this stage of the crisis? Like, how much of a difference can we still make?

We can absolutely make a difference.

So if you look at any of the kind of future pathways, the range of possible climate futures, um, you know, the trajectory we take is very much determined by the decisions we make today and tomorrow and the next day.

And, and, and we're very much, um, the driving force of the, the trajectory that we take, the final temperature rise that we end up in.

I mean, people have a sense that there is often some single threshold in the system that once we pass that, it's over, there's nothing we can do to stop this.

This is generally not how climate impacts work.

What's really clear is that the higher the warming, the higher the impacts, right? So going from 1.5 to 1.6 to 1.7 to one point...

Burned a lot of shit.

How do you think about our agency at this stage of the crisis? How much of a difference can we still make?

We can absolutely make a difference.

So if you look at any of the kind of future pathways, the range of possible climate futures, um, you know, the trajectory we take is very much determined by the decisions we make today and tomorrow and the next day, and, and, and we're very much, um, the driving force of the, the trajectory that we take, the final temperature rise that we end up in.

I think people have a sense that there is often some single threshold in the system that once we pass that, it's over, there's nothing we can do to stop this.

This is generally not how climate impacts work.

What's really clear is that the higher the warming, the higher the impacts, right? So going from 1.5 to 1.6 to 1.7 to one point...

All of those incremental increases in global temperatures make a difference to the impacts.

Burned a lot of shit.

Just elaborate for us on what that is.

Yeah, it's difficult because of, as you say, I think just giving people a ton of information doesn't shift them that dramatically.

I think there are a small percentage of people that are maybe very, very open and just make decisions based on data.

I think they're quite rare.

But I think I often use the frame that data is necessary, but not adequate in order to do this.

So there is, I think one key thing is what really doesn't work is for someone to say something and you to say, no, you're wrong.

that they automatically shut down.

So how important is it that we get over that roadblock of Yes, we're on board, but are we going to actually push now in this room rather than waiting for somebody else to solve the problem?

What happens when the wind doesn't blow and the sun doesn't shine?

I opened that chapter by pointing out that, you know, the people that design wind turbines and the engineers that design the stuff, they know that actually the wind doesn't blow all the time.

This is not news to them.

But people like to point out this all the time.

And it is obviously is a valid concern, right? Like we don't just want...

cheap power.

We want cheap, reliable power that's available 24-7.

Well, sure, but can we build the grid to those places fast enough?