5. How much clean electricity do we really need (subtitles)
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Hello, how is everyone feeling?
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(Cheers)
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Are you ready to solve climate change?
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(Cheers)
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Good.
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Do you know what a pettawat hour is?
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Yeah, it's a unit of energy like kilowatt hour or megawatt hour.
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I've been a climate activist since age 11
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and I studied engineering,
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and so I was familiar with those terms.
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Kilowatt, megawatt, even gigawatt and terawatt.
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But I had never heard of a petawatt hour
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until I wrote a book on climate change solutions.
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That's because it's so big.
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But that's the scale I want to talk about.
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A petawatt hour is a trillion kilowatt hours.
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And today the world generates about 25 trillion kilowatt hours
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of electricity each year.
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Most of that is from fossil-fuel power plants,
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and the dominant mindset is that we have to change
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the current electricity system
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by replacing those fossil-fuel plants
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with clean generation by 2050.
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Well, over one third of our electricity generation is already clean,
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mostly from hydro and nuclear,
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along with wind and solar,
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and clean generation is growing.
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Projections based on current policies around the world show
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that we are on track to have about 25 petawatt hours
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of clean electricity generation in 2050.
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That's two and a half times today's amount of clean generation
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and equal to today's total generation.
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So this is great.
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We can replace all our fossil fuel plants,
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have a clean version of today's world,
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walk away, we've solved climate change.
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Thank you very much.
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Oh, but I did forget one tiny little detail.
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We actually need five times that much.
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To be clear, we need and we're on track to have
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two and a half times today's amount of clean generation
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to switch to a clean version of our current electricity system.
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But changing the current system isn't enough.
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We need five times that,
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all of it clean,
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or 12 times today's clean electricity production,
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to actually avoid the worst impacts of climate change.
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Can I repeat that?
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To avoid the worst impacts of climate change,
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we have to multiply today's clean electricity production by 12 times.
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There are four main reasons we need that much.
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First, let’s keep in mind scientists’ goalpost for addressing climate change:
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achieving net-negative emissions globally by around 2050.
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Most of us know that to do so,
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we'll have to electrify a whole range of vehicles,
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heating systems and some industrial processes.
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Electric equipment is more efficient than fuel-based equipment.
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So electrification actually lowers total global energy demand,
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but it increases electricity generation needed.
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In our current energy world,
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electrifying 60 percent, which is ambitious,
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would add enough demand
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that we would need roughly 40 petawatt hours
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of total electricity generation by 2050.
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Second, it's not OK to simply replace today's world with a clean version.
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In today's world,
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over 700 million people don't have access to electricity.
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Billions more have access only to small amounts
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or to unreliable supply that often cuts out.
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Energy demand in rich industrialized countries will grow more slowly
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over the next few decades with increased efficiency.
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But energy demand in developing countries will continue to grow dramatically,
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especially if we can make electricity cheaper.
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This is good.
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Energy access is lifting people out of poverty,
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driving access to education,
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commerce, health care and lower birth rates.
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Both for moral and practical reasons,
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those of us in richer countries need to realize that addressing climate change
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will necessarily center
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on a massive expansion of energy access in developing countries.
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So electricity generation will have to grow even more
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and get cheaper
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to accommodate global economic development.
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Based on projections of global development by 2050,
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generation needed rises to 60 petawatt hours per year.
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The third reason is a bit more debatable,
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but it needs to be talked about more in public discourse.
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It has to do with the fact
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that not everything can be electrified by 2050.
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Long-range airplanes, for instance,
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are still going to need the energy density of a liquid fuel.
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Similar for some industrial processes.
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Now, many models waive this issue away with two overoptimistic assumptions:
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that all those factories continue burning fossil fuels but use carbon capture,
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which costs extra and will only happen where governments mandate it,
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and that all those long-range vehicles use sustainable biofuel,
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which is only sustainable if every supplying country,
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and its local governments,
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fully enforces strict standards for biomass
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to avoid deforestation and other impacts
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that could increase emissions from agriculture.
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Some amount of carbon capture at factories and sustainable bioenergy
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will absolutely be part of the picture.
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But I’ve been in politics,
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and I am sure that we should plan for imperfect policy.
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And that means we need to plan
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for building even more electricity generation.
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We can use this additional generation to synthesize fuels
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that are truly carbon neutral or entirely carbon free:
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hydrogen, ammonia, synthetic jet fuel and others.
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This is a much rougher estimate,
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but to be confident of minimizing climate change impacts,
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we should aim to push our line up to around 90 petawatt hours per year.
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Finally, the fourth reason is that we need not only net-zero
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but net-negative emissions in 2050.
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There will be some non-energy emissions that remain, especially from agriculture.
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And we'll have to pull CO2 from the atmosphere
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to make up for those.
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But we also need to use all our possible carbon-removal methods
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at their maximum capacity
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to remove more CO2 each year,
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getting as far as possible in o net-negative emissions,
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drawing down levels of greenhouse gases in the atmosphere
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to eventually restore a stable climate.
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One of the carbon-removal methods we’ll have to use is direct air-capture:
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arrays of fans filtering CO2 from the air.
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And doing enough of this to restore safe temperatures within decades,
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not centuries,
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will require yet more electricity generation.
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Again, the exact amount depends on quite how ambitious we're able to be.
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But for a comfortable rate of carbon removal,
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we would need perhaps 120 petawatt hours per year total.
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So roughly five times today's total global electricity system,
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12 times today's clean electricity production,
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and that can actually achieve net-negative emissions globally.
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And there's a bonus reason to consider.
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Because clean electricity is going to power so much
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of the rest of the transition: electrification, global development,
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synthesized fuels and sequestration,
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to achieve net-negative emissions by 2050,
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we should really build as much as possible
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of that new electricity generation
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at the beginning of the transition, starting now.
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This will make sure that clean electricity is abundant
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and cheap soon enough
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to still leave time for all of the other transitions that rely on it
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to fully roll out by 2050.
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And when we talk about abundant and cheap electricity,
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we're talking about eliminating poverty faster,
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powering access to water desalination,
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strengthening medical supply chains,
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so much more.
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Decarbonizing and scaling electricity generation
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will also be the biggest global development project ever.
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So if we want to avoid the worst of climate change,
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we need to discard that dominant mindset
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about merely replacing fossil fuel generation.
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My point is, that misses the scale.
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Our project is not changing the current global electricity system.
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Our project is building a new global electricity system.
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Political action that tinkers around within the current system
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will never get us where we need to be by 2050.
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Arguments over which sources of clean electricity we should use are unhelpful.
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We need all of them:
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hydro, solar, wind, nuclear, advanced nuclear,
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advanced geothermal,
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mandates for carbon capture on remaining fossil plants.
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If you look at the potential rates of addition for each of these,
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you'll see we need everything as much as possible
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and we may still fall short.
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It's not changing the electricity system.
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It's building a new electricity system.
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One five times bigger than today's total system
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and 100 percent clean.
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As fellow youth activists often say,
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the project is much more comparable
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to the World War II-era manufacturing boom
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than anything the world has done since.
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Building new things that we've barely ever built before,
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in massive amounts, to create a new system entirely.
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In fact, this mindset goes beyond electricity-generation itself.
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Many people are wary of ambitious climate action
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because they see the project as changing the familiar current world.
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That's not it.
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Addressing climate change means building a new world.
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A world in which energy is healthier,
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doesn't pollute the air we breathe
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and where it's cheaper and everyone globally has access to it.
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A world with higher incomes,
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longer and better lives,
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greater equality.
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A better world.
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Thank you, and let's make it happen.
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(Applause)