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Emergency medicine for our climate fever

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    I'm here to talk to you about something
    important that may be new to you.
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    The governments of the world
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    are about to conduct
    an unintentional experiment
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    on our climate.
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    In 2020, new rules will require ships
    to lower their sulfur emissions
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    by scrubbing their dirty exhaust
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    or switching to cleaner fuels.
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    For human health, this is really good,
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    but sulfur particles
    in the emission of ships
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    also have an effect on clouds.
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    This is a satellite image of marine clouds
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    off the Pacific West Coast
    of the United States.
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    The streaks in the clouds
    are created by the exhaust from ships.
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    Ships' emissions include
    both greenhouse gases,
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    which trap heat over long periods of time,
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    and particulates like sulfates
    that mix with clouds
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    and temporarily make them brighter.
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    Brighter clouds reflect
    more sunlight back to space,
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    cooling the climate.
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    So in fact,
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    humans are currently running
    two unintentional experiments
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    on our climate.
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    In the first one, we're increasing
    the concentration of greenhouse gases
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    and gradually warming the earth system.
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    This works something like a fever
    in the human body.
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    If the fever remains low,
    its effects are mild,
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    but as the fever rises,
    damage grows more severe
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    and eventually devastating.
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    We're seeing a little of this now.
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    In our other experiment,
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    we're planning to remove
    a layer of particles
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    that brighten clouds and shield us
    from some of this warming.
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    The effect is strongest
    in ocean clouds like these,
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    and scientists expect the reduction
    of sulfur emissions from ships next year
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    to produce a measurable increase
    in global warming.
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    Bit of a shocker?
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    In fact, most emissions contain sulfates
    that brighten clouds:
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    coal, diesel exhaust, forest fires.
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    Scientists estimate that the total
    cooling effect from emission particles,
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    which they call aerosols
    when they're in the climate,
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    may be as much as all of the warming
    we've experienced up until now.
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    There's a lot of uncertainty
    around this effect,
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    and it's one of the major reasons
    why we have difficulty predicting climate,
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    but this is cooling that we'll lose
    as emissions fall.
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    So to be clear, humans
    are currently cooling the planet
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    by dispersing particles
    into the atmosphere at massive scale.
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    We just don't know how much,
    and we're doing it accidentally.
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    That's worrying,
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    but it could mean that we have
    a fast-acting way to reduce warming,
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    emergency medicine
    for our climate fever if we needed it,
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    and it's a medicine
    with origins in nature.
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    This is a NASA simulation
    of earth's atmosphere,
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    showing clouds and particles
    moving over the planet.
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    The brightness is the Sun's light
    reflecting from particles in clouds,
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    and this reflective shield
    is one of the primary ways
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    that nature keeps the planet
    cool enough for humans
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    and all of the life that we know.
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    In 2015, scientists assessed possibilities
    for rapidly cooling climate.
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    They discounted
    things like mirrors in space,
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    ping-pong balls in the ocean,
    plastic sheets on the Arctic,
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    and they found
    that the most viable approaches
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    involved slightly increasing
    this atmospheric reflectivity.
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    In fact, it's possible that reflecting
    just one or two percent more sunlight
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    from the atmosphere
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    could offset two degrees Celsius
    or more of warming.
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    Now, I'm a technology executive,
    not a scientist.
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    About a decade ago,
    concerned about climate,
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    I started to talk with scientists about
    potential countermeasures to warming.
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    These conversations grew
    into collaborations
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    that became the Marine
    Cloud Brightening Project,
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    which I'll talk about momentarily,
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    and the nonprofit policy organization
    SilverLining, where I am today.
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    I work with politicians, researchers,
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    members of the tech industry and others
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    to talk about some of these ideas.
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    Early on, I met British
    atmospheric scientist John Latham,
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    who proposed cooling the climate
    the way that the ships do,
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    but with a natural source of particles:
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    sea-salt mist from seawater
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    sprayed from ships into areas
    of susceptible clouds over the ocean.
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    The approach became known
    by the name I gave it then,
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    "marine cloud brightening."
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    Early modeling studies suggested
    that by deploying marine cloud brightening
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    in just 10 to 20 percent
    of susceptible ocean clouds,
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    it might be possible to offset
    as much as two degrees Celsius's warming.
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    It might even be possible
    to brighten clouds in local regions
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    to reduce the impacts caused
    by warming ocean surface temperatures.
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    For example, regions
    such as the Gulf Atlantic
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    might be cooled in the months
    before a hurricane season
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    to reduce the force of storms.
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    Or, it might be possible to cool waters
    flowing onto coral reefs
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    overwhelmed by heat stress,
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    like Australia's Great Barrier Reef.
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    But these ideas are only theoretical,
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    and brightening marine clouds
    is not the only way
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    to increase the reflection
    of the sunlight from the atmosphere.
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    Another occurs when large volcanoes
    release material with enough force
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    to reach the upper layer
    of the atmosphere, the stratosphere.
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    When Mount Pinatubo erupted in 1991,
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    it released material
    into the stratosphere,
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    including sulfates that mix
    with the atmosphere to reflect sunlight.
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    This material remained
    and circulated around the planet.
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    It was enough to cool the climate
    by over half a degree Celsius
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    for about two years.
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    This cooling led to a striking increase
    in Arctic ice cover in 1992,
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    which dropped in subsequent years
    as the particles fell back to earth.
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    But the volcanic phenomenon
    led Nobel Prize winner Paul Crutzen
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    to propose the idea that dispersing
    particles into the stratosphere
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    in a controlled way might be
    a way to counter global warming.
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    Now, this has risks
    that we don't understand,
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    including things like
    heating up the stratosphere
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    or damage to the ozone layer.
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    Scientists think that there could be
    safe approaches to this,
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    but is this really where we are?
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    Is this really worth considering?
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    This is a simulation
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    from the US National Center
    for Atmospheric Research
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    global climate model showing,
    earth surface temperatures through 2100.
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    The globe on the left visualizes
    our current trajectory,
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    and on the right, a world where particles
    are introduced into the stratosphere
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    gradually in 2020,
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    and maintained through 2100.
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    Intervention keeps surface temperatures
    near those of today,
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    while without it, temperatures rise
    well over three degrees.
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    This could be the difference
    between a safe and an unsafe world.
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    So, if there's even a chance
    that this could be close to reality,
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    is this something
    we should consider seriously?
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    Today, there are no capabilities,
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    and scientific knowledge
    is extremely limited.
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    We don't know whether these types
    of interventions are even feasible,
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    or how to characterize their risks.
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    Researchers hope to explore
    some basic questions
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    that might help us know
    whether or not these might be real options
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    or whether we should rule them out.
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    It requires multiple ways
    of studying the climate system,
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    including computer models
    to forecast changes,
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    analytic techniques like machine learning,
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    and many types of observations.
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    And though it's controversial,
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    it's also critical that researchers
    develop core technologies
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    and perform small-scale,
    real-world experiments.
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    There are two research programs
    proposing experiments like this.
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    At Harvard, the SCoPEx experiment
    would release very small amounts
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    of sulfates, calcium carbonate and water
    into the stratosphere with a balloon,
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    to study chemistry and physics effects.
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    How much material?
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    Less than the amount released
    in one minute of flight
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    from a commercial aircraft.
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    So this is definitely not dangerous,
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    and it may not even be scary.
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    At the University of Washington,
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    scientists hope to spray
    a fine mist of salt water into clouds
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    in a series of land and ocean tests.
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    If those are successful,
    this would culminate in experiments
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    to measurably brighten
    an area of clouds over the ocean.
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    The marine cloud brightening effort
    is the first to develop any technology
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    for generating aerosols for atmospheric
    sunlight reflection in this way.
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    It requires producing
    very tiny particles --
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    think about the mist that comes
    out of an asthma inhaler --
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    at massive scale -- so think
    of looking up at a cloud.
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    It's a tricky engineering problem.
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    So this one nozzle they developed
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    generates three trillion
    particles per second,
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    80 nanometers in size,
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    from very corrosive saltwater.
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    It was developed by a team
    of retired engineers in Silicon Valley --
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    here they are --
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    working full-time for six years,
    without pay, for their grandchildren.
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    It will take a few million dollars
    and another year or two
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    to develop the full spray system
    they need to do these experiments.
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    In other parts of the world,
    research efforts are emerging,
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    including small modeling programs
    at Beijing Normal University in China,
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    the Indian Institute of Science,
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    a proposed center for climate repair
    at Cambridge University in the UK
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    and the DECIMALS Fund,
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    which sponsors researchers
    in global South countries
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    to study the potential impacts
    of these sunlight interventions
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    in their part of the world.
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    But all of these programs,
    including the experimental ones,
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    lack significant funding.
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    And understanding
    these interventions is a hard problem.
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    The earth is a vast, complex system
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    and we need major investments
    in climate models, observations
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    and basic science
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    to be able to predict climate
    much better than we can today
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    and manage both our accidental
    and any intentional interventions.
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    And it could be urgent.
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    Recent scientific reports
    predict that in the next few decades,
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    earth's fever is on a path to devastation:
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    extreme heat and fires,
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    major loss of ocean life,
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    collapse of Arctic ice,
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    displacement and suffering
    for hundreds of millions of people.
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    The fever could even reach tipping points
    where warming takes over
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    and human efforts are no longer enough
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    to counter accelerating changes
    in natural systems.
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    To prevent this circumstance,
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    the UN's International Panel
    on Climate Change predicts
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    that we need to stop
    and even reverse emissions by 2050.
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    How? We have to quickly and radically
    transform major economic sectors,
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    including energy, construction,
    agriculture, transportation and others.
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    And it is imperative that we do this
    as fast as we can.
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    But our fever is now so high
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    that climate experts say
    we also have to remove
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    massive quantities of CO2
    from the atmosphere,
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    possibly 10 times
    all of the world's annual emissions,
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    in ways that aren't proven yet.
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    Right now, we have slow-moving solutions
    to a fast-moving problem.
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    Even with the most optimistic assumptions,
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    our exposure to risk
    in the next 10 to 30 years
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    is unacceptably high, in my opinion.
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    Could interventions like these
    provide fast-acting medicine if we need it
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    to reduce the earth's fever
    while we address its underlying causes?
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    There are real concerns about this idea.
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    Some people are very worried
    that even researching these interventions
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    could provide an excuse to delay efforts
    to reduce emissions.
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    This is also known as a moral hazard.
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    But, like most medicines,
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    interventions are more dangerous
    the more that you do,
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    so research actually
    tends to draw out the fact
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    that we absolutely,
    positively cannot continue
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    to fill up the atmosphere
    with greenhouse gases,
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    that these kinds of alternatives are risky
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    and if we were to use them,
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    we would need to use
    as little as possible.
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    But even so,
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    could we ever learn enough
    about these interventions
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    to manage the risk?
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    Who would make decisions
    about when and how to intervene?
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    What if some people are worse off,
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    or they just think they are?
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    These are really hard problems.
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    But what really worries me
    is that as climate impacts worsen,
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    leaders will be called on to respond
    by any means available.
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    I for one don't want them to act
    without real information
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    and much better options.
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    Scientists think it will take
    a decade of research
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    just to assess these interventions,
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    before we ever were
    to develop or use them.
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    Yet today, the global level of investment
    in these interventions
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    is effectively zero.
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    So, we need to move quickly
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    if we want policymakers
    to have real information
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    on this kind of emergency medicine.
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    There is hope!
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    The world has solved
    these kinds of problems before.
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    In the 1970s, we identified
    an existential threat
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    to our protective ozone layer.
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    In the 1980s, scientists,
    politicians and industry
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    came together in a solution to replace
    the chemicals causing the problem.
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    They achieved this with the only
    legally binding environmental agreement
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    signed by all countries in the world,
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    the Montreal Protocol.
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    Still in force today,
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    it has resulted in a recovery
    of the ozone layer
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    and is the most successful
    environmental protection effort
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    in human history.
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    We have a far greater threat now,
  • 14:04 - 14:08
    but we do have the ability
    to develop and agree on solutions
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    to protect people
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    and restore our climate to health.
  • 14:12 - 14:15
    This could mean that to remain safe,
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    we reflect sunlight for a few decades,
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    while we green our industries
    and remove CO2.
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    It definitely means we must work now
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    to understand our options
    for this kind of emergency medicine.
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    Thank you,
  • 14:31 - 14:36
    (Applause)
Title:
Emergency medicine for our climate fever
Speaker:
Kelly Wanser
Description:

As we recklessly warm the planet by pumping greenhouse gases into the atmosphere, some industrial emissions also produce particles that reflect sunshine back into space, putting a check on global warming that we're only starting to understand. Climate activist Kelly Wanser asks: Can we engineer ways to harness this effect and further reduce warming? Learn about the promises and risks of "cloud brightening" -- and how it could help restore our climate to health.

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Video Language:
English
Team:
TED
Project:
TEDTalks
Duration:
14:49

English subtitles

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