[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.84,0:00:04.74,Default,,0000,0000,0000,,I'm here to talk to you about something\Nimportant that may be new to you.
Dialogue: 0,0:00:05.26,0:00:06.64,Default,,0000,0000,0000,,The governments of the world
Dialogue: 0,0:00:06.67,0:00:08.93,Default,,0000,0000,0000,,are about to conduct\Nan unintentional experiment
Dialogue: 0,0:00:08.96,0:00:10.71,Default,,0000,0000,0000,,on our climate.
Dialogue: 0,0:00:10.74,0:00:16.05,Default,,0000,0000,0000,,In 2020, new rules will require ships\Nto lower their sulfur emissions
Dialogue: 0,0:00:16.07,0:00:18.18,Default,,0000,0000,0000,,by scrubbing their dirty exhaust
Dialogue: 0,0:00:18.20,0:00:20.15,Default,,0000,0000,0000,,or switching to cleaner fuels.
Dialogue: 0,0:00:20.70,0:00:23.34,Default,,0000,0000,0000,,For human health, this is really good,
Dialogue: 0,0:00:23.36,0:00:25.70,Default,,0000,0000,0000,,but sulfur particles\Nin the emission of ships
Dialogue: 0,0:00:25.72,0:00:28.48,Default,,0000,0000,0000,,also have an effect on clouds.
Dialogue: 0,0:00:28.98,0:00:31.48,Default,,0000,0000,0000,,This is a satellite image of marine clouds
Dialogue: 0,0:00:31.51,0:00:34.03,Default,,0000,0000,0000,,off the Pacific West Coast\Nof the United States.
Dialogue: 0,0:00:34.48,0:00:37.79,Default,,0000,0000,0000,,The streaks in the clouds\Nare created by the exhaust from ships.
Dialogue: 0,0:00:38.14,0:00:41.01,Default,,0000,0000,0000,,Ships' emissions include\Nboth greenhouse gases,
Dialogue: 0,0:00:41.04,0:00:43.87,Default,,0000,0000,0000,,which trap heat over long periods of time,
Dialogue: 0,0:00:43.90,0:00:47.11,Default,,0000,0000,0000,,and particulates like sulfates\Nthat mix with clouds
Dialogue: 0,0:00:47.14,0:00:48.97,Default,,0000,0000,0000,,and temporarily make them brighter.
Dialogue: 0,0:00:49.67,0:00:52.96,Default,,0000,0000,0000,,Brighter clouds reflect\Nmore sunlight back to space,
Dialogue: 0,0:00:52.99,0:00:54.28,Default,,0000,0000,0000,,cooling the climate.
Dialogue: 0,0:00:55.26,0:00:56.64,Default,,0000,0000,0000,,So in fact,
Dialogue: 0,0:00:56.67,0:00:59.58,Default,,0000,0000,0000,,humans are currently running\Ntwo unintentional experiments
Dialogue: 0,0:00:59.60,0:01:00.75,Default,,0000,0000,0000,,on our climate.
Dialogue: 0,0:01:01.19,0:01:05.23,Default,,0000,0000,0000,,In the first one, we're increasing\Nthe concentration of greenhouse gases
Dialogue: 0,0:01:05.25,0:01:07.32,Default,,0000,0000,0000,,and gradually warming the earth system.
Dialogue: 0,0:01:07.71,0:01:11.15,Default,,0000,0000,0000,,This works something like a fever\Nin the human body.
Dialogue: 0,0:01:11.17,0:01:14.56,Default,,0000,0000,0000,,If the fever remains low,\Nits effects are mild,
Dialogue: 0,0:01:14.58,0:01:17.46,Default,,0000,0000,0000,,but as the fever rises,\Ndamage grows more severe
Dialogue: 0,0:01:17.48,0:01:19.44,Default,,0000,0000,0000,,and eventually devastating.
Dialogue: 0,0:01:19.75,0:01:21.63,Default,,0000,0000,0000,,We're seeing a little of this now.
Dialogue: 0,0:01:22.74,0:01:23.96,Default,,0000,0000,0000,,In our other experiment,
Dialogue: 0,0:01:23.99,0:01:26.61,Default,,0000,0000,0000,,we're planning to remove\Na layer of particles
Dialogue: 0,0:01:26.63,0:01:29.86,Default,,0000,0000,0000,,that brighten clouds and shield us\Nfrom some of this warming.
Dialogue: 0,0:01:30.31,0:01:33.51,Default,,0000,0000,0000,,The effect is strongest\Nin ocean clouds like these,
Dialogue: 0,0:01:33.54,0:01:39.00,Default,,0000,0000,0000,,and scientists expect the reduction\Nof sulfur emissions from ships next year
Dialogue: 0,0:01:39.03,0:01:42.40,Default,,0000,0000,0000,,to produce a measurable increase\Nin global warming.
Dialogue: 0,0:01:43.59,0:01:44.74,Default,,0000,0000,0000,,Bit of a shocker?
Dialogue: 0,0:01:45.69,0:01:49.88,Default,,0000,0000,0000,,In fact, most emissions contain sulfates\Nthat brighten clouds:
Dialogue: 0,0:01:49.90,0:01:53.47,Default,,0000,0000,0000,,coal, diesel exhaust, forest fires.
Dialogue: 0,0:01:54.15,0:01:57.85,Default,,0000,0000,0000,,Scientists estimate that the total\Ncooling effect from emission particles,
Dialogue: 0,0:01:57.87,0:02:00.70,Default,,0000,0000,0000,,which they call aerosols\Nwhen they're in the climate,
Dialogue: 0,0:02:01.16,0:02:05.72,Default,,0000,0000,0000,,may be as much as all of the warming\Nwe've experienced up until now.
Dialogue: 0,0:02:05.75,0:02:08.76,Default,,0000,0000,0000,,There's a lot of uncertainty\Naround this effect,
Dialogue: 0,0:02:08.78,0:02:13.11,Default,,0000,0000,0000,,and it's one of the major reasons\Nwhy we have difficulty predicting climate,
Dialogue: 0,0:02:13.13,0:02:17.14,Default,,0000,0000,0000,,but this is cooling that we'll lose\Nas emissions fall.
Dialogue: 0,0:02:17.97,0:02:21.94,Default,,0000,0000,0000,,So to be clear, humans\Nare currently cooling the planet
Dialogue: 0,0:02:22.90,0:02:26.62,Default,,0000,0000,0000,,by dispersing particles\Ninto the atmosphere at massive scale.
Dialogue: 0,0:02:26.64,0:02:29.67,Default,,0000,0000,0000,,We just don't know how much,\Nand we're doing it accidentally.
Dialogue: 0,0:02:30.58,0:02:32.53,Default,,0000,0000,0000,,That's worrying,
Dialogue: 0,0:02:32.55,0:02:35.97,Default,,0000,0000,0000,,but it could mean that we have\Na fast-acting way to reduce warming,
Dialogue: 0,0:02:35.100,0:02:39.61,Default,,0000,0000,0000,,emergency medicine\Nfor our climate fever if we needed it,
Dialogue: 0,0:02:39.63,0:02:42.41,Default,,0000,0000,0000,,and it's a medicine\Nwith origins in nature.
Dialogue: 0,0:02:44.27,0:02:47.12,Default,,0000,0000,0000,,This is a NASA simulation\Nof earth's atmosphere,
Dialogue: 0,0:02:47.14,0:02:49.72,Default,,0000,0000,0000,,showing clouds and particles\Nmoving over the planet.
Dialogue: 0,0:02:50.45,0:02:54.92,Default,,0000,0000,0000,,The brightness is the Sun's light\Nreflecting from particles in clouds,
Dialogue: 0,0:02:54.95,0:02:58.67,Default,,0000,0000,0000,,and this reflective shield\Nis one of the primary ways
Dialogue: 0,0:02:58.69,0:03:01.08,Default,,0000,0000,0000,,that nature keeps the planet\Ncool enough for humans
Dialogue: 0,0:03:01.10,0:03:02.76,Default,,0000,0000,0000,,and all of the life that we know.
Dialogue: 0,0:03:03.66,0:03:08.55,Default,,0000,0000,0000,,In 2015, scientists assessed possibilities\Nfor rapidly cooling climate.
Dialogue: 0,0:03:09.00,0:03:12.24,Default,,0000,0000,0000,,They discounted\Nthings like mirrors in space,
Dialogue: 0,0:03:12.26,0:03:17.10,Default,,0000,0000,0000,,ping-pong balls in the ocean,\Nplastic sheets on the Arctic,
Dialogue: 0,0:03:17.12,0:03:19.50,Default,,0000,0000,0000,,and they found\Nthat the most viable approaches
Dialogue: 0,0:03:19.52,0:03:23.59,Default,,0000,0000,0000,,involved slightly increasing\Nthis atmospheric reflectivity.
Dialogue: 0,0:03:24.41,0:03:28.77,Default,,0000,0000,0000,,In fact, it's possible that reflecting\Njust one or two percent more sunlight
Dialogue: 0,0:03:28.79,0:03:30.74,Default,,0000,0000,0000,,from the atmosphere
Dialogue: 0,0:03:30.77,0:03:34.24,Default,,0000,0000,0000,,could offset two degrees Celsius\Nor more of warming.
Dialogue: 0,0:03:35.60,0:03:39.24,Default,,0000,0000,0000,,Now, I'm a technology executive,\Nnot a scientist.
Dialogue: 0,0:03:39.26,0:03:42.07,Default,,0000,0000,0000,,About a decade ago,\Nconcerned about climate,
Dialogue: 0,0:03:42.09,0:03:46.23,Default,,0000,0000,0000,,I started to talk with scientists about\Npotential countermeasures to warming.
Dialogue: 0,0:03:46.99,0:03:50.00,Default,,0000,0000,0000,,These conversations grew\Ninto collaborations
Dialogue: 0,0:03:50.03,0:03:52.35,Default,,0000,0000,0000,,that became the Marine\NCloud Brightening Project,
Dialogue: 0,0:03:52.38,0:03:54.66,Default,,0000,0000,0000,,which I'll talk about momentarily,
Dialogue: 0,0:03:54.68,0:03:58.73,Default,,0000,0000,0000,,and the nonprofit policy organization\NSilverLining, where I am today.
Dialogue: 0,0:03:59.48,0:04:03.07,Default,,0000,0000,0000,,I work with politicians, researchers,
Dialogue: 0,0:04:03.09,0:04:05.07,Default,,0000,0000,0000,,members of the tech industry and others
Dialogue: 0,0:04:05.09,0:04:07.23,Default,,0000,0000,0000,,to talk about some of these ideas.
Dialogue: 0,0:04:08.04,0:04:11.28,Default,,0000,0000,0000,,Early on, I met British\Natmospheric scientist John Latham,
Dialogue: 0,0:04:11.31,0:04:14.32,Default,,0000,0000,0000,,who proposed cooling the climate\Nthe way that the ships do,
Dialogue: 0,0:04:14.34,0:04:16.65,Default,,0000,0000,0000,,but with a natural source of particles:
Dialogue: 0,0:04:16.68,0:04:19.32,Default,,0000,0000,0000,,sea-salt mist from seawater
Dialogue: 0,0:04:19.34,0:04:22.57,Default,,0000,0000,0000,,sprayed from ships into areas\Nof susceptible clouds over the ocean.
Dialogue: 0,0:04:23.37,0:04:26.23,Default,,0000,0000,0000,,The approach became known\Nby the name I gave it then,
Dialogue: 0,0:04:26.25,0:04:27.82,Default,,0000,0000,0000,,"marine cloud brightening."
Dialogue: 0,0:04:27.84,0:04:32.30,Default,,0000,0000,0000,,Early modeling studies suggested\Nthat by deploying marine cloud brightening
Dialogue: 0,0:04:32.33,0:04:35.91,Default,,0000,0000,0000,,in just 10 to 20 percent\Nof susceptible ocean clouds,
Dialogue: 0,0:04:35.94,0:04:40.58,Default,,0000,0000,0000,,it might be possible to offset\Nas much as two degrees Celsius's warming.
Dialogue: 0,0:04:41.20,0:04:44.13,Default,,0000,0000,0000,,It might even be possible\Nto brighten clouds in local regions
Dialogue: 0,0:04:44.15,0:04:48.74,Default,,0000,0000,0000,,to reduce the impacts caused\Nby warming ocean surface temperatures.
Dialogue: 0,0:04:48.76,0:04:51.57,Default,,0000,0000,0000,,For example, regions\Nsuch as the Gulf Atlantic
Dialogue: 0,0:04:51.60,0:04:54.22,Default,,0000,0000,0000,,might be cooled in the months\Nbefore a hurricane season
Dialogue: 0,0:04:54.24,0:04:56.58,Default,,0000,0000,0000,,to reduce the force of storms.
Dialogue: 0,0:04:56.61,0:05:00.53,Default,,0000,0000,0000,,Or, it might be possible to cool waters\Nflowing onto coral reefs
Dialogue: 0,0:05:00.55,0:05:02.16,Default,,0000,0000,0000,,overwhelmed by heat stress,
Dialogue: 0,0:05:02.18,0:05:04.24,Default,,0000,0000,0000,,like Australia's Great Barrier Reef.
Dialogue: 0,0:05:04.26,0:05:07.01,Default,,0000,0000,0000,,But these ideas are only theoretical,
Dialogue: 0,0:05:07.03,0:05:10.16,Default,,0000,0000,0000,,and brightening marine clouds\Nis not the only way
Dialogue: 0,0:05:10.18,0:05:13.48,Default,,0000,0000,0000,,to increase the reflection\Nof the sunlight from the atmosphere.
Dialogue: 0,0:05:14.06,0:05:19.02,Default,,0000,0000,0000,,Another occurs when large volcanoes\Nrelease material with enough force
Dialogue: 0,0:05:19.04,0:05:22.24,Default,,0000,0000,0000,,to reach the upper layer\Nof the atmosphere, the stratosphere.
Dialogue: 0,0:05:22.70,0:05:25.98,Default,,0000,0000,0000,,When Mount Pinatubo erupted in 1991,
Dialogue: 0,0:05:26.01,0:05:28.01,Default,,0000,0000,0000,,it released material\Ninto the stratosphere,
Dialogue: 0,0:05:28.03,0:05:32.49,Default,,0000,0000,0000,,including sulfates that mix\Nwith the atmosphere to reflect sunlight.
Dialogue: 0,0:05:33.31,0:05:36.36,Default,,0000,0000,0000,,This material remained\Nand circulated around the planet.
Dialogue: 0,0:05:36.100,0:05:40.97,Default,,0000,0000,0000,,It was enough to cool the climate\Nby over half a degree Celsius
Dialogue: 0,0:05:40.99,0:05:42.66,Default,,0000,0000,0000,,for about two years.
Dialogue: 0,0:05:44.01,0:05:50.03,Default,,0000,0000,0000,,This cooling led to a striking increase\Nin Arctic ice cover in 1992,
Dialogue: 0,0:05:50.05,0:05:54.32,Default,,0000,0000,0000,,which dropped in subsequent years\Nas the particles fell back to earth.
Dialogue: 0,0:05:54.35,0:05:58.17,Default,,0000,0000,0000,,But the volcanic phenomenon\Nled Nobel Prize winner Paul Crutzen
Dialogue: 0,0:05:58.19,0:06:01.49,Default,,0000,0000,0000,,to propose the idea that dispersing\Nparticles into the stratosphere
Dialogue: 0,0:06:01.52,0:06:05.11,Default,,0000,0000,0000,,in a controlled way might be\Na way to counter global warming.
Dialogue: 0,0:06:05.96,0:06:08.88,Default,,0000,0000,0000,,Now, this has risks\Nthat we don't understand,
Dialogue: 0,0:06:08.91,0:06:11.64,Default,,0000,0000,0000,,including things like\Nheating up the stratosphere
Dialogue: 0,0:06:11.66,0:06:13.69,Default,,0000,0000,0000,,or damage to the ozone layer.
Dialogue: 0,0:06:13.72,0:06:18.23,Default,,0000,0000,0000,,Scientists think that there could be\Nsafe approaches to this,
Dialogue: 0,0:06:18.26,0:06:19.85,Default,,0000,0000,0000,,but is this really where we are?
Dialogue: 0,0:06:19.88,0:06:22.63,Default,,0000,0000,0000,,Is this really worth considering?
Dialogue: 0,0:06:23.49,0:06:24.78,Default,,0000,0000,0000,,This is a simulation
Dialogue: 0,0:06:24.80,0:06:27.41,Default,,0000,0000,0000,,from the US National Center\Nfor Atmospheric Research
Dialogue: 0,0:06:27.43,0:06:31.87,Default,,0000,0000,0000,,global climate model showing,\Nearth surface temperatures through 2100.
Dialogue: 0,0:06:31.89,0:06:35.88,Default,,0000,0000,0000,,The globe on the left visualizes\Nour current trajectory,
Dialogue: 0,0:06:35.91,0:06:39.58,Default,,0000,0000,0000,,and on the right, a world where particles\Nare introduced into the stratosphere
Dialogue: 0,0:06:39.60,0:06:40.99,Default,,0000,0000,0000,,gradually in 2020,
Dialogue: 0,0:06:41.02,0:06:43.64,Default,,0000,0000,0000,,and maintained through 2100.
Dialogue: 0,0:06:43.66,0:06:47.95,Default,,0000,0000,0000,,Intervention keeps surface temperatures\Nnear those of today,
Dialogue: 0,0:06:47.97,0:06:52.22,Default,,0000,0000,0000,,while without it, temperatures rise\Nwell over three degrees.
Dialogue: 0,0:06:52.24,0:06:56.15,Default,,0000,0000,0000,,This could be the difference\Nbetween a safe and an unsafe world.
Dialogue: 0,0:06:57.85,0:07:01.72,Default,,0000,0000,0000,,So, if there's even a chance\Nthat this could be close to reality,
Dialogue: 0,0:07:01.74,0:07:04.35,Default,,0000,0000,0000,,is this something\Nwe should consider seriously?
Dialogue: 0,0:07:06.23,0:07:07.96,Default,,0000,0000,0000,,Today, there are no capabilities,
Dialogue: 0,0:07:07.99,0:07:10.61,Default,,0000,0000,0000,,and scientific knowledge\Nis extremely limited.
Dialogue: 0,0:07:11.34,0:07:15.89,Default,,0000,0000,0000,,We don't know whether these types\Nof interventions are even feasible,
Dialogue: 0,0:07:15.91,0:07:17.96,Default,,0000,0000,0000,,or how to characterize their risks.
Dialogue: 0,0:07:18.76,0:07:21.89,Default,,0000,0000,0000,,Researchers hope to explore\Nsome basic questions
Dialogue: 0,0:07:21.91,0:07:26.07,Default,,0000,0000,0000,,that might help us know\Nwhether or not these might be real options
Dialogue: 0,0:07:26.10,0:07:27.77,Default,,0000,0000,0000,,or whether we should rule them out.
Dialogue: 0,0:07:28.69,0:07:32.11,Default,,0000,0000,0000,,It requires multiple ways\Nof studying the climate system,
Dialogue: 0,0:07:32.13,0:07:35.24,Default,,0000,0000,0000,,including computer models\Nto forecast changes,
Dialogue: 0,0:07:35.27,0:07:37.55,Default,,0000,0000,0000,,analytic techniques like machine learning,
Dialogue: 0,0:07:37.57,0:07:39.61,Default,,0000,0000,0000,,and many types of observations.
Dialogue: 0,0:07:40.60,0:07:42.38,Default,,0000,0000,0000,,And though it's controversial,
Dialogue: 0,0:07:42.40,0:07:46.54,Default,,0000,0000,0000,,it's also critical that researchers\Ndevelop core technologies
Dialogue: 0,0:07:46.56,0:07:49.98,Default,,0000,0000,0000,,and perform small-scale,\Nreal-world experiments.
Dialogue: 0,0:07:51.19,0:07:54.52,Default,,0000,0000,0000,,There are two research programs\Nproposing experiments like this.
Dialogue: 0,0:07:55.41,0:07:59.50,Default,,0000,0000,0000,,At Harvard, the SCoPEx experiment\Nwould release very small amounts
Dialogue: 0,0:07:59.52,0:08:04.100,Default,,0000,0000,0000,,of sulfates, calcium carbonate and water\Ninto the stratosphere with a balloon,
Dialogue: 0,0:08:05.02,0:08:07.96,Default,,0000,0000,0000,,to study chemistry and physics effects.
Dialogue: 0,0:08:08.96,0:08:10.30,Default,,0000,0000,0000,,How much material?
Dialogue: 0,0:08:10.87,0:08:13.55,Default,,0000,0000,0000,,Less than the amount released\Nin one minute of flight
Dialogue: 0,0:08:13.58,0:08:15.03,Default,,0000,0000,0000,,from a commercial aircraft.
Dialogue: 0,0:08:15.65,0:08:18.31,Default,,0000,0000,0000,,So this is definitely not dangerous,
Dialogue: 0,0:08:18.34,0:08:19.94,Default,,0000,0000,0000,,and it may not even be scary.
Dialogue: 0,0:08:21.11,0:08:23.18,Default,,0000,0000,0000,,At the University of Washington,
Dialogue: 0,0:08:23.20,0:08:27.34,Default,,0000,0000,0000,,scientists hope to spray\Na fine mist of salt water into clouds
Dialogue: 0,0:08:27.36,0:08:29.94,Default,,0000,0000,0000,,in a series of land and ocean tests.
Dialogue: 0,0:08:29.97,0:08:32.78,Default,,0000,0000,0000,,If those are successful,\Nthis would culminate in experiments
Dialogue: 0,0:08:32.80,0:08:36.05,Default,,0000,0000,0000,,to measurably brighten\Nan area of clouds over the ocean.
Dialogue: 0,0:08:36.74,0:08:40.67,Default,,0000,0000,0000,,The marine cloud brightening effort\Nis the first to develop any technology
Dialogue: 0,0:08:40.69,0:08:44.72,Default,,0000,0000,0000,,for generating aerosols for atmospheric\Nsunlight reflection in this way.
Dialogue: 0,0:08:45.17,0:08:47.95,Default,,0000,0000,0000,,It requires producing\Nvery tiny particles --
Dialogue: 0,0:08:47.98,0:08:52.44,Default,,0000,0000,0000,,think about the mist that comes\Nout of an asthma inhaler --
Dialogue: 0,0:08:52.47,0:08:55.67,Default,,0000,0000,0000,,at massive scale -- so think\Nof looking up at a cloud.
Dialogue: 0,0:08:56.50,0:08:58.71,Default,,0000,0000,0000,,It's a tricky engineering problem.
Dialogue: 0,0:08:59.42,0:09:01.03,Default,,0000,0000,0000,,So this one nozzle they developed
Dialogue: 0,0:09:01.06,0:09:03.70,Default,,0000,0000,0000,,generates three trillion\Nparticles per second,
Dialogue: 0,0:09:03.72,0:09:05.74,Default,,0000,0000,0000,,80 nanometers in size,
Dialogue: 0,0:09:05.76,0:09:07.50,Default,,0000,0000,0000,,from very corrosive saltwater.
Dialogue: 0,0:09:08.68,0:09:12.29,Default,,0000,0000,0000,,It was developed by a team\Nof retired engineers in Silicon Valley --
Dialogue: 0,0:09:12.32,0:09:13.86,Default,,0000,0000,0000,,here they are --
Dialogue: 0,0:09:13.88,0:09:18.89,Default,,0000,0000,0000,,working full-time for six years,\Nwithout pay, for their grandchildren.
Dialogue: 0,0:09:19.33,0:09:22.22,Default,,0000,0000,0000,,It will take a few million dollars\Nand another year or two
Dialogue: 0,0:09:22.25,0:09:25.69,Default,,0000,0000,0000,,to develop the full spray system\Nthey need to do these experiments.
Dialogue: 0,0:09:26.75,0:09:30.35,Default,,0000,0000,0000,,In other parts of the world,\Nresearch efforts are emerging,
Dialogue: 0,0:09:30.38,0:09:34.71,Default,,0000,0000,0000,,including small modeling programs\Nat Beijing Normal University in China,
Dialogue: 0,0:09:34.73,0:09:37.06,Default,,0000,0000,0000,,the Indian Institute of Science,
Dialogue: 0,0:09:37.09,0:09:41.78,Default,,0000,0000,0000,,a proposed center for climate repair\Nat Cambridge University in the UK
Dialogue: 0,0:09:41.80,0:09:44.01,Default,,0000,0000,0000,,and the DECIMALS Fund,
Dialogue: 0,0:09:44.03,0:09:46.73,Default,,0000,0000,0000,,which sponsors researchers\Nin global South countries
Dialogue: 0,0:09:46.75,0:09:49.72,Default,,0000,0000,0000,,to study the potential impacts\Nof these sunlight interventions
Dialogue: 0,0:09:49.74,0:09:51.14,Default,,0000,0000,0000,,in their part of the world.
Dialogue: 0,0:09:51.95,0:09:56.05,Default,,0000,0000,0000,,But all of these programs,\Nincluding the experimental ones,
Dialogue: 0,0:09:56.07,0:09:57.67,Default,,0000,0000,0000,,lack significant funding.
Dialogue: 0,0:09:58.60,0:10:01.51,Default,,0000,0000,0000,,And understanding\Nthese interventions is a hard problem.
Dialogue: 0,0:10:01.54,0:10:03.96,Default,,0000,0000,0000,,The earth is a vast, complex system
Dialogue: 0,0:10:03.98,0:10:06.90,Default,,0000,0000,0000,,and we need major investments\Nin climate models, observations
Dialogue: 0,0:10:06.92,0:10:08.47,Default,,0000,0000,0000,,and basic science
Dialogue: 0,0:10:08.50,0:10:12.32,Default,,0000,0000,0000,,to be able to predict climate\Nmuch better than we can today
Dialogue: 0,0:10:12.34,0:10:16.20,Default,,0000,0000,0000,,and manage both our accidental\Nand any intentional interventions.
Dialogue: 0,0:10:17.52,0:10:18.73,Default,,0000,0000,0000,,And it could be urgent.
Dialogue: 0,0:10:20.11,0:10:24.10,Default,,0000,0000,0000,,Recent scientific reports\Npredict that in the next few decades,
Dialogue: 0,0:10:24.13,0:10:26.93,Default,,0000,0000,0000,,earth's fever is on a path to devastation:
Dialogue: 0,0:10:26.96,0:10:28.78,Default,,0000,0000,0000,,extreme heat and fires,
Dialogue: 0,0:10:29.88,0:10:32.00,Default,,0000,0000,0000,,major loss of ocean life,
Dialogue: 0,0:10:32.81,0:10:34.68,Default,,0000,0000,0000,,collapse of Arctic ice,
Dialogue: 0,0:10:35.78,0:10:39.38,Default,,0000,0000,0000,,displacement and suffering\Nfor hundreds of millions of people.
Dialogue: 0,0:10:40.28,0:10:43.98,Default,,0000,0000,0000,,The fever could even reach tipping points\Nwhere warming takes over
Dialogue: 0,0:10:44.00,0:10:46.24,Default,,0000,0000,0000,,and human efforts are no longer enough
Dialogue: 0,0:10:46.26,0:10:49.17,Default,,0000,0000,0000,,to counter accelerating changes\Nin natural systems.
Dialogue: 0,0:10:49.85,0:10:52.12,Default,,0000,0000,0000,,To prevent this circumstance,
Dialogue: 0,0:10:52.14,0:10:54.78,Default,,0000,0000,0000,,the UN's International Panel\Non Climate Change predicts
Dialogue: 0,0:10:54.81,0:10:58.31,Default,,0000,0000,0000,,that we need to stop\Nand even reverse emissions by 2050.
Dialogue: 0,0:10:59.11,0:11:03.84,Default,,0000,0000,0000,,How? We have to quickly and radically\Ntransform major economic sectors,
Dialogue: 0,0:11:03.86,0:11:08.10,Default,,0000,0000,0000,,including energy, construction,\Nagriculture, transportation and others.
Dialogue: 0,0:11:08.90,0:11:13.40,Default,,0000,0000,0000,,And it is imperative that we do this\Nas fast as we can.
Dialogue: 0,0:11:13.43,0:11:15.46,Default,,0000,0000,0000,,But our fever is now so high
Dialogue: 0,0:11:15.48,0:11:17.69,Default,,0000,0000,0000,,that climate experts say\Nwe also have to remove
Dialogue: 0,0:11:17.72,0:11:20.67,Default,,0000,0000,0000,,massive quantities of CO2\Nfrom the atmosphere,
Dialogue: 0,0:11:20.69,0:11:24.30,Default,,0000,0000,0000,,possibly 10 times\Nall of the world's annual emissions,
Dialogue: 0,0:11:24.32,0:11:26.15,Default,,0000,0000,0000,,in ways that aren't proven yet.
Dialogue: 0,0:11:27.03,0:11:31.09,Default,,0000,0000,0000,,Right now, we have slow-moving solutions\Nto a fast-moving problem.
Dialogue: 0,0:11:32.02,0:11:34.13,Default,,0000,0000,0000,,Even with the most optimistic assumptions,
Dialogue: 0,0:11:34.15,0:11:37.43,Default,,0000,0000,0000,,our exposure to risk\Nin the next 10 to 30 years
Dialogue: 0,0:11:37.45,0:11:39.90,Default,,0000,0000,0000,,is unacceptably high, in my opinion.
Dialogue: 0,0:11:40.81,0:11:44.49,Default,,0000,0000,0000,,Could interventions like these\Nprovide fast-acting medicine if we need it
Dialogue: 0,0:11:44.52,0:11:48.06,Default,,0000,0000,0000,,to reduce the earth's fever\Nwhile we address its underlying causes?
Dialogue: 0,0:11:48.62,0:11:51.22,Default,,0000,0000,0000,,There are real concerns about this idea.
Dialogue: 0,0:11:51.25,0:11:54.61,Default,,0000,0000,0000,,Some people are very worried\Nthat even researching these interventions
Dialogue: 0,0:11:54.63,0:11:58.79,Default,,0000,0000,0000,,could provide an excuse to delay efforts\Nto reduce emissions.
Dialogue: 0,0:11:58.81,0:12:01.14,Default,,0000,0000,0000,,This is also known as a moral hazard.
Dialogue: 0,0:12:02.01,0:12:03.89,Default,,0000,0000,0000,,But, like most medicines,
Dialogue: 0,0:12:03.92,0:12:07.18,Default,,0000,0000,0000,,interventions are more dangerous\Nthe more that you do,
Dialogue: 0,0:12:07.20,0:12:09.69,Default,,0000,0000,0000,,so research actually\Ntends to draw out the fact
Dialogue: 0,0:12:09.72,0:12:12.79,Default,,0000,0000,0000,,that we absolutely,\Npositively cannot continue
Dialogue: 0,0:12:12.81,0:12:15.63,Default,,0000,0000,0000,,to fill up the atmosphere\Nwith greenhouse gases,
Dialogue: 0,0:12:15.66,0:12:18.13,Default,,0000,0000,0000,,that these kinds of alternatives are risky
Dialogue: 0,0:12:18.16,0:12:20.53,Default,,0000,0000,0000,,and if we were to use them,
Dialogue: 0,0:12:20.55,0:12:22.93,Default,,0000,0000,0000,,we would need to use\Nas little as possible.
Dialogue: 0,0:12:24.75,0:12:26.68,Default,,0000,0000,0000,,But even so,
Dialogue: 0,0:12:26.70,0:12:29.40,Default,,0000,0000,0000,,could we ever learn enough\Nabout these interventions
Dialogue: 0,0:12:29.43,0:12:31.00,Default,,0000,0000,0000,,to manage the risk?
Dialogue: 0,0:12:31.44,0:12:35.21,Default,,0000,0000,0000,,Who would make decisions\Nabout when and how to intervene?
Dialogue: 0,0:12:35.72,0:12:38.25,Default,,0000,0000,0000,,What if some people are worse off,
Dialogue: 0,0:12:38.27,0:12:40.10,Default,,0000,0000,0000,,or they just think they are?
Dialogue: 0,0:12:40.54,0:12:42.39,Default,,0000,0000,0000,,These are really hard problems.
Dialogue: 0,0:12:43.51,0:12:48.49,Default,,0000,0000,0000,,But what really worries me\Nis that as climate impacts worsen,
Dialogue: 0,0:12:48.51,0:12:51.97,Default,,0000,0000,0000,,leaders will be called on to respond\Nby any means available.
Dialogue: 0,0:12:52.84,0:12:56.02,Default,,0000,0000,0000,,I for one don't want them to act\Nwithout real information
Dialogue: 0,0:12:56.04,0:12:57.88,Default,,0000,0000,0000,,and much better options.
Dialogue: 0,0:12:58.76,0:13:01.09,Default,,0000,0000,0000,,Scientists think it will take\Na decade of research
Dialogue: 0,0:13:01.12,0:13:03.26,Default,,0000,0000,0000,,just to assess these interventions,
Dialogue: 0,0:13:03.29,0:13:05.68,Default,,0000,0000,0000,,before we ever were\Nto develop or use them.
Dialogue: 0,0:13:06.39,0:13:10.80,Default,,0000,0000,0000,,Yet today, the global level of investment\Nin these interventions
Dialogue: 0,0:13:10.82,0:13:12.87,Default,,0000,0000,0000,,is effectively zero.
Dialogue: 0,0:13:14.06,0:13:16.79,Default,,0000,0000,0000,,So, we need to move quickly
Dialogue: 0,0:13:16.82,0:13:20.04,Default,,0000,0000,0000,,if we want policymakers\Nto have real information
Dialogue: 0,0:13:20.06,0:13:22.03,Default,,0000,0000,0000,,on this kind of emergency medicine.
Dialogue: 0,0:13:24.17,0:13:25.32,Default,,0000,0000,0000,,There is hope!
Dialogue: 0,0:13:26.62,0:13:29.18,Default,,0000,0000,0000,,The world has solved\Nthese kinds of problems before.
Dialogue: 0,0:13:29.56,0:13:32.97,Default,,0000,0000,0000,,In the 1970s, we identified\Nan existential threat
Dialogue: 0,0:13:32.99,0:13:34.76,Default,,0000,0000,0000,,to our protective ozone layer.
Dialogue: 0,0:13:35.66,0:13:38.50,Default,,0000,0000,0000,,In the 1980s, scientists,\Npoliticians and industry
Dialogue: 0,0:13:38.52,0:13:42.50,Default,,0000,0000,0000,,came together in a solution to replace\Nthe chemicals causing the problem.
Dialogue: 0,0:13:42.94,0:13:46.45,Default,,0000,0000,0000,,They achieved this with the only\Nlegally binding environmental agreement
Dialogue: 0,0:13:46.47,0:13:48.65,Default,,0000,0000,0000,,signed by all countries in the world,
Dialogue: 0,0:13:48.68,0:13:50.62,Default,,0000,0000,0000,,the Montreal Protocol.
Dialogue: 0,0:13:50.64,0:13:52.65,Default,,0000,0000,0000,,Still in force today,
Dialogue: 0,0:13:52.68,0:13:55.46,Default,,0000,0000,0000,,it has resulted in a recovery\Nof the ozone layer
Dialogue: 0,0:13:55.48,0:13:58.43,Default,,0000,0000,0000,,and is the most successful\Nenvironmental protection effort
Dialogue: 0,0:13:58.45,0:13:59.91,Default,,0000,0000,0000,,in human history.
Dialogue: 0,0:14:01.10,0:14:03.70,Default,,0000,0000,0000,,We have a far greater threat now,
Dialogue: 0,0:14:03.72,0:14:07.95,Default,,0000,0000,0000,,but we do have the ability\Nto develop and agree on solutions
Dialogue: 0,0:14:07.98,0:14:09.52,Default,,0000,0000,0000,,to protect people
Dialogue: 0,0:14:09.54,0:14:11.60,Default,,0000,0000,0000,,and restore our climate to health.
Dialogue: 0,0:14:12.41,0:14:15.18,Default,,0000,0000,0000,,This could mean that to remain safe,
Dialogue: 0,0:14:15.20,0:14:17.54,Default,,0000,0000,0000,,we reflect sunlight for a few decades,
Dialogue: 0,0:14:17.56,0:14:20.72,Default,,0000,0000,0000,,while we green our industries\Nand remove CO2.
Dialogue: 0,0:14:21.66,0:14:24.92,Default,,0000,0000,0000,,It definitely means we must work now
Dialogue: 0,0:14:24.94,0:14:29.20,Default,,0000,0000,0000,,to understand our options\Nfor this kind of emergency medicine.
Dialogue: 0,0:14:29.90,0:14:31.05,Default,,0000,0000,0000,,Thank you,
Dialogue: 0,0:14:31.08,0:14:35.78,Default,,0000,0000,0000,,(Applause)