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Translator: Amanda Chu Reviewer: Peter van de Ven
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Thank you very much.
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When I was a boy,
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my parents would sometimes take me camping in California.
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We would camp in the beaches, in the forests, in the deserts.
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Some people think the deserts are empty of life,
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but my parents taught me to see the wildlife all around us,
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the hawks, the eagles, the tortoises.
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One time when we were setting up camp,
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we found a baby scorpion with its stinger out,
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and I remember thinking how cool it was
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that something could be both so cute and also so dangerous.
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After college, I moved to California,
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and I started working on a number of environmental campaigns.
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I got involved in helping to save the state's last ancient redwood forest
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and blocking a proposed radioactive waste repository
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set for the desert.
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Shortly after I turned 30,
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I decided I wanted to dedicate a significant amount of my life
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to solving climate change.
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I was worried that global warming would end up destroying
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many of the natural environments that people had worked so hard to protect.
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I thought the technical solutions were pretty straightforward -
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solar panels on every roof, electric car in the driveway -
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that the main obstacles were political.
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And so I helped to organize a coalition
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of the country's biggest labor unions and biggest environmental groups.
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Our proposal was for a 300-billion-dollar investment in renewables.
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And the idea was not only would we prevent climate change,
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but we would also create millions of new jobs
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in a very fast-growing high-tech sector.
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Our efforts really paid off in 2007,
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when then-presidential candidate Barack Obama embraced our vision.
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And between 2009 and 2015, the US invested 150 billion dollars
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in renewables and other kinds of clean tech.
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But right away, we started to encounter some problems.
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So first of all, the electricity from solar rooftops
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ends up costing about twice as much as the electricity from solar farms.
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And both solar farms and wind farms
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require covering a pretty significant amount of land
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with solar panels and wind turbines
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and also building very big transmission lines
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to bring all that electricity from the countryside into the city.
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Both of those things were often very strongly resisted by local communities,
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as well as by conservation biologists
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who were concerned about the impacts on wild-bird species and other animals.
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Now, there was a lot of other people
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working on technical solutions at the time.
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One of the big challenges, of course, is the intermittency of solar and wind.
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They only generate electricity about 10 to 30 percent of the time
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during most of year.
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But some of the solutions being proposed
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were to convert hydroelectric dams into gigantic batteries.
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The idea was that when the sun was shining and the wind was blowing,
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you would pump the water uphill, store it for later,
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and then when you needed electricity, run it over the turbines.
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In terms of wildlife, some of these problems
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just didn't seem like a significant concern.
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So when I learned that house cats kill billions of birds every year,
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it put into perspective the hundreds of thousands of birds
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that are killed by wind turbines.
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It basically seemed to me at the time
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that most, if not all, of the problems of scaling up solar and wind
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could be solved through more technological innovation.
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But as the years went by,
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these problems persisted and, in many cases, grew worse.
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So California is a state that's really committed to renewable energy,
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but we still haven't converted many of our hydroelectric dams
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into big batteries.
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Some of the problems are just geographic;
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it's just you have to have a very particular kind of formation
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to be able to do that,
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and even in those cases,
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it's quite expensive to make those conversions.
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Other challenges are just that there's other uses for water,
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like irrigation,
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and maybe the most significant problem
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is just that in California the water in our rivers and reservoirs
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is growing increasingly scarce and unreliable
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due to climate change.
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In terms of this issue of reliability, as a consequence of it,
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we've actually had to stop the electricity
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coming from the solar farms into the cities
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because there's just been too much of it at times.
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Or we've been starting to pay our neighboring states, like Arizona,
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to take that solar electricity.
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The alternative is to suffer from blowouts of the grid.
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And it turns out that when it comes to birds and cats -
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cats don't kill eagles; eagles kill cats.
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What cats kill are the small common sparrows and jays and robins,
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birds that are not endangered and not at risk of going extinct.
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What do kill eagles and other big birds,
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like this kite as well as owls and condors
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and other threatened and endangered species,
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are wind turbines;
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in fact, they're one of the most significant threats
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to those big bird species that we have.
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We just haven't been introducing the airspace with many other objects
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like we have wind turbines over the last several years.
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And in terms of solar,
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you know, building a solar farm is a lot like building any other kind of farm:
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you have to clear the whole area of wildlife.
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So this is a picture of one third of one of the biggest solar farms in California,
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called Ivanpah.
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In order to build this,
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they had to clear the whole area of desert tortoises,
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literally pulling desert tortoises and their babies out of burrows,
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putting them on the back of pickup trucks, and transporting them to captivity,
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where many of them ended up dying.
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And the current estimates are that about 6,000 birds are killed every year,
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actually catching on fire above the solar farm
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and plunging to their deaths.
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Over time, it gradually struck me
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that there was really no amount of technological innovation
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that was going to make the sun shine more regularly
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or wind blow more reliably;
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in fact, you could make solar panels cheaper,
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and you could make wind turbines bigger,
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but sunlight and wind are just really dilute fuels,
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and in order to produce significant amounts of electricity,
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you just have to cover a very large land mass with them.
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In other words, all of the major problems with renewables aren't technical,
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they're natural.
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Well, dealing with all of this unreliability
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and the big environmental impacts
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obviously comes at a pretty high economic cost.
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We've been hearing a lot
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about how solar panels and wind turbines have come down in cost in recent years,
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but that cost has been significantly outweighed
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by just the challenges of integrating all of that unreliable power onto the grid.
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Just take, for instance, what's happened in California.
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At the period in which solar panels have come down in price
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very significantly, same with wind,
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we've seen our electricity prices go up
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five times more than the rest of the country.
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And it's not unique to us.
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You can see the same phenomenon happened in Germany,
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which is really the world's leader
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in solar, wind and other renewable technologies.
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Their prices increased 50 percent during their big renewable-energy push.
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Now you might think, well, dealing with climate change
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is just going to require that we all pay more for energy.
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That's what I used to think.
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But consider the case of France.
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France actually gets twice as much of its electricity
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from clean zero-emission sources than does Germany,
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and yet France pays almost half as much for its electricity.
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How can that be?
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You might have already anticipated the answer.
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France gets most of its electricity from nuclear power, about 75% in total.
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And nuclear just ends up being a lot more reliable,
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generating power 24 hours a day, seven days a week,
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for about 90% of the year.
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We see this phenomenon show up at a global level.
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So, for example, there's been a natural experiment
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over the last 40 years,
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even more than that,
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in terms of the deployment of nuclear and the deployment of solar.
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You can see that at a little bit higher cost,
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we got about half as much electricity from solar and wind
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than we did from nuclear.
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Well, what does all this mean for going forward?
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I think one of the most significant findings to date is this one.
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Had Germany spent 580 billion dollars on nuclear instead of renewables,
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it would already be getting a hundred percent of its electricity
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from clean energy sources, and all of its transportation energy.
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Now I think you might be wondering, and it's quite reasonable to ask:
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Is nuclear power safe? And what do you do with the waste?
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Well, those are very reasonable questions.
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Turns out that there's been scientific studies on this
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going over 40 years.
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This is just the most recent study,
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that was done by the prestigious British medical journal Lancet,
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finds that nuclear power is the safest.
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It's easy to understand why.
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According to the WHO,
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about 7 million people die annually from air pollution.
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And nuclear plants don't emit that.
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As a result, the climate scientist James Hansen looked at it.
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He calculated that nuclear power has already saved
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almost two million lives to date.
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It turns out that even wind energy is more deadly than nuclear.
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This is a photograph taken of two maintenance workers
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in the Netherlands,
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shortly before one of them fell to his death to avoid the fire,
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and the other one was engulfed in flames.
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Now, what about environmental impact?
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I think a really easy way to think about it
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is that uranium fuel, which is what we used to power nuclear plants,
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is just really energy dense.
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About the same amount of uranium as this Rubik's Cube
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can power all of the energy you need in your entire life.
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As a consequence,
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you just don't need that much land
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in order to produce a significant amount of electricity.
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Here you can compare the solar farm I just described, Ivanpah,
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to California's last nuclear plant,
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Diablo Canyon.
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It takes 450 times more land to generate the same amount of electricity
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as it does from nuclear.
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You would need 17 more solar farms like Ivanpah
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in order to generate the same output as Diablo Canyon,
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and of course, it would then be unreliable.
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Well, what about the mining and the waste and the material throughput.
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This has been studied pretty closely as well,
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and it just turns out
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that solar panels require 17 times more materials than nuclear plants do,
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in the form of cement, glass, concrete, steel -
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and that includes all the fuel used for those nuclear plants.
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The consequence is that what comes out at the end, since its material throughput,
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is just not a lot of waste from nuclear.
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All of the waste from the Swiss nuclear program fits into this room.
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Nuclear waste is actually the only waste from electricity production
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that's safely contained and internalized.
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Every other way of making electricity
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emits that waste into the natural environment,
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either as pollution or as material waste.
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We tend to think of solar panels as clean,
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but the truth is that there is no plan
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to deal with solar panels at the end of their 20 or 25-year life.
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A lot of experts are actually very concerned that solar panels
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are just going to be shipped to poor countries in Africa or Asia,
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with the rest of our electronic-waste stream,
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to be disassembled,
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often exposing people to really high level of toxic elements,
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including lead, cadmium and chromium,
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elements that because they're elements, their toxicity never declines over time.
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I think we have an intuitive sense
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that nuclear is a really powerful strong energy source
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and that sunlight is really dilute and diffuse and weak,
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which is why you have to spread solar collectors or wind collectors
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over such a large amount of land.
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Maybe that's why nobody was surprised
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when in the recent science-fiction remake of Blade Runner,
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the film opens with a very dark dystopian scene
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where California's deserts have been entirely paved with solar farms.
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All of which, I think, raises a really uncomfortable question:
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In the effort to try to save the climate, are we destroying the environment?
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The interesting thing is that over the last several hundred years,
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human beings have actually been trying to move away
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from what you would consider matter-dense fuels
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towards energy-dense ones.
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That means, really, from wood and dung towards coal, oil, natural gas, uranium.
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This is a phenomenon that's been going on for a long time.
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Poor countries around the world are in the process still
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of moving away from wood and dung as primary energies.
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And for the most part, this is a positive thing.
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As you stop using wood as your major source of fuel,
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it allows the forests to grow back and the wildlife to return.