Climate Change: Chemistry, International Assessment and Policy
The seminar focuses on the underlying chemistry associated with climate change: sources and sinks of greenhouse gases, and how these gases trap heat in the Earth's atmosphere.
Information will be drawn from the Intergovernmental Panel on Climate Change (IPCC Fifth Assessment, Physical Science Basis), chemistry textbooks, and publicly accessible databases of greenhouse gas emissions, including a breakdown by country, and the global temperature record. Impacts on the environment to date, including melting ice caps and rising sea levels, and future predictions of climate change will be explored. The environmental and energy policies proposed by presidential and congressional candidates, along with what individuals can do to reduce their carbon footprint, will be discussed and debated.
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[00:00:01.629]The two talks are very different.
[00:00:02.917]Tonight's talk is what I teach.
[00:00:05.795]I felt a passion over the years of trying to
[00:00:11.262]expose students who were not science majors
[00:00:14.806]to some of the important challenges
[00:00:17.838]in career opportunities and scientific challenges,
[00:00:22.495]and policy issues that surrounded environmental chemistry.
[00:00:28.336]So the course I teach is Chemistry for the Environment.
[00:00:30.490]It is for a non-science majors
[00:00:33.452]and it's been well-received over the years
[00:00:36.916]and I have adopted a section of that
[00:00:39.042]on climate change for tonight.
[00:00:40.866]And my sense was that it would be,
[00:00:44.702]it would be fun to present this educational component
[00:00:47.954]of our work because the thing that I like the most about it
[00:00:52.839]is teaching students without a science background,
[00:00:57.264]some quantitative skills,
[00:00:58.664]using Excel spreadsheets to look at the data themselves,
[00:01:01.754]to go to websites and download
[00:01:04.780]and examine the current data on greenhouse gases
[00:01:09.576]and temperature changes in the environment
[00:01:11.448]and many other things.
[00:01:12.857]And so, I'll be,
[00:01:15.766]and then discussing that in terms of policy,
[00:01:17.951]ripping off the headlines of the New York Times
[00:01:20.664]or the Economist or the Wall Street Journal,
[00:01:23.845]of how any of these subjects matter in a broader context.
[00:01:28.793]So that's what I'm gonna talk about tonight
[00:01:30.673]and then tomorrow, please forgive me
[00:01:32.753]but my passion is my laboratory and technical research
[00:01:36.327]and so tomorrow I will be telling you how
[00:01:39.809]as a physical chemist I've been able to,
[00:01:41.351]my group and I have been able to have
[00:01:44.852]some pretty significant findings that impact on,
[00:01:49.696]on atmospheric chemistry.
[00:01:52.859]So as I said this talk tonight is about
[00:01:57.658]how giving you a snapshot of how I,
[00:02:00.863]I teach this material to Penn undergraduates.
[00:02:06.999]Okay, so this is the course,
[00:02:10.923]Chemistry in the Environment,
[00:02:12.402]and I've said a few of things again
[00:02:14.202]but let me, but let me emphasize.
[00:02:16.612]I'm, I really try to focus on topics
[00:02:20.496]that are, that have, where I can teach chemistry,
[00:02:24.633]but use it in the context of environmental issues.
[00:02:28.911]I try to pool every week from the headlines
[00:02:31.492]and you'll see in a few moments,
[00:02:32.828]we have things from happen this past weekend in the talk,
[00:02:36.107]and we do do quantitative exercises so I must say
[00:02:40.343]that many English majors probably haven't used
[00:02:42.865]an Excel spreadsheet and we think
[00:02:44.395]that we're teaching them an important tool in the process.
[00:02:47.479]So might look at,
[00:02:48.799]and we do look at plod up the growth
[00:02:52.100]in greenhouse gas emissions
[00:02:53.594]or the global temperature record,
[00:02:56.346]and we have fun with it as well.
[00:02:59.466]In an election year which I won't do tonight,
[00:03:02.068]but in an election year I will very often ask students
[00:03:04.536]to go to the platform of a particular candidate
[00:03:09.067]and present their opinions on their policies and plans
[00:03:15.997]for both the environment and energy.
[00:03:19.290]So tonight what I'd like to do is just talk about
[00:03:24.461]why a physical chemist,
[00:03:26.188]or how a physical chemist thinks
[00:03:27.996]about greenhouse gas concentration changes,
[00:03:30.735]why it impacts on the temperature changes
[00:03:32.768]and our environment and talk a little bit
[00:03:36.216]about big important changes in international agreements
[00:03:42.506]that are hopeful I think for the future.
[00:03:47.467]So this is the issue.
[00:03:49.009]We all know that, I hope,
[00:03:51.914]we all know that we're change,
[00:03:54.564]we as humans are changing our environment.
[00:03:57.990]We are increasing certain gases in the atmosphere
[00:04:01.601]as we burn fossil fuels
[00:04:03.839]and our world is changing,
[00:04:06.253]and we all are going to need to adjust
[00:04:08.265]to a society when the climate is at a minimum
[00:04:13.403]variable and ultimately changing and warmer
[00:04:16.822]than it is now.
[00:04:18.499]And the problem is that this potentially,
[00:04:22.981]and I'm not an expert at this part but
[00:04:24.770]potentially has enormous possibilities
[00:04:29.745]for disrupting our current
[00:04:32.051]way of life.
[00:04:34.603]It could have, here in Nebraska,
[00:04:36.373]huge changes in agricultural, water supply,
[00:04:38.879]we discussed this this afternoon.
[00:04:40.576]Transportation, I live close to the Coast,
[00:04:45.144]Coastal communities will may be under water,
[00:04:47.803]as you'll see in a few moments.
[00:04:49.833]And then the big issues about economy, energy,
[00:04:52.284]what will be our new energy sources
[00:04:54.014]if not from burning fossil fuels?
[00:04:56.621]How will ecosystems, and as we just mentioned,
[00:04:58.991]National Security change?
[00:05:00.934]So the scientific fact and
[00:05:04.345]that's the part I'm gonna focus on,
[00:05:05.684]is what is the human influence on our climate,
[00:05:11.277]and how, what, how much greenhouse gases
[00:05:14.976]have we emitted?
[00:05:16.527]What are greenhouse gases
[00:05:17.773]and how much have we emitted them into the atmosphere,
[00:05:20.176]and how quickly is it changing?
[00:05:22.907]And I think that's the part that I as a scientist like,
[00:05:26.289]often look at.
[00:05:28.960]So, my journey actually began in teaching this course,
[00:05:34.075]with this BBC News report,
[00:05:37.683]which I'm not gonna play for you,
[00:05:39.595]but I often start my class this way.
[00:05:41.949]So if you go back and look at
[00:05:44.653]ice cores that have been dug into the
[00:05:47.979]Antarctic Region and look at gas bubbles
[00:05:52.179]that are contained in those ice cores,
[00:05:55.758]and you can trace back the history
[00:05:59.018]of the earth's atmosphere of 800,000 years.
[00:06:02.798]And over that time,
[00:06:04.795]from 800,000 years ago to the present,
[00:06:08.070]essentially you see that the
[00:06:10.770]amount of carbon dioxide,
[00:06:13.601]and this is in parts per million,
[00:06:15.575]ocellated some over time,
[00:06:17.364]these actually have to do with
[00:06:19.017]ice ages and changes in the way the
[00:06:23.016]earth rotates, orbits around the sun,
[00:06:27.241]but for all of this very very long time,
[00:06:30.631]the amount of carbon dioxide in the atmosphere
[00:06:32.856]was below 300 parts per million,
[00:06:35.573]and that's that red dash line that you see here.
[00:06:39.182]And if we come to the present,
[00:06:44.496]here is an article from the New York Times in 2013,
[00:06:48.014]May of 2013 where they presented much the same
[00:06:51.760]information going back here 400,000 years,
[00:06:56.236]and really emphasizing that the amount of carbon dioxide
[00:06:59.383]in our atmosphere ocellated between
[00:07:03.267]about 180 parts per million,
[00:07:05.588]and 280 parts per million,
[00:07:07.647]over a very very long period of time.
[00:07:12.336]And then as we move in through the Industrial Revolution
[00:07:16.952]and industrial changes you can see
[00:07:20.583]that all of a sudden,
[00:07:21.727]today if you will,
[00:07:23.938]and we'll blow that up in a moment,
[00:07:26.028]and I'm sure you've all seen this,
[00:07:27.918]that the amount of carbon dioxide in the atmosphere
[00:07:31.134]has dramatically changed.
[00:07:32.522]So we were below 280 parts per million for
[00:07:35.856]for you know essentially forever,
[00:07:38.553]and in the last 100 years,
[00:07:41.396]we have rapidly exceeded it,
[00:07:46.057]and this was a New York Times article
[00:07:48.615]that was really emphasizing in May of 2013,
[00:07:52.372]for the first time we crossed the 400 part per million
[00:07:55.947]concentration level, the amount of carbon dioxide
[00:07:59.883]in the atmosphere.
[00:08:01.536]Well when they plodded it in
[00:08:03.366]a very long long period of time,
[00:08:05.209]it sort of, people called this the Hockey Stick,
[00:08:08.712]Hockey Stick kind of graph,
[00:08:11.271]because it changes so rapidly in modern times,
[00:08:14.747]and is relatively flat,
[00:08:16.263]but of course if you expand that data, (clears throat)
[00:08:19.539]over recent times,
[00:08:20.782]you can see data that was recorded in Mauna Loa in Hawaii,
[00:08:25.033]where carbon dioxide levels appear to be more gradually
[00:08:28.757]changing and I'm gonna come back and talk about that
[00:08:31.670]more in a moment.
[00:08:33.451]You see some oscillations due to seasonal average,
[00:08:36.155]seasonal variations and it looks more gradual
[00:08:40.409]than when you look over all time.
[00:08:44.779]So here is a blow-up of this,
[00:08:46.805]and so one of the things that I do in my class
[00:08:49.029]is to not just present this data and gloss over it
[00:08:53.434]as we're looking at it tonight,
[00:08:54.982]but to plod it up.
[00:08:57.297]And why do I like to plod it up,
[00:08:59.345]and use Excel to analyze this data?
[00:09:03.020]It's because to me it just looks like a gradual change,
[00:09:07.049]when I look at the graph,
[00:09:08.318]but when I as a scientist sit down and graph it,
[00:09:12.669]and I take the slope over,
[00:09:14.528]let's say a different decades,
[00:09:16.380]what you begin to notice right away
[00:09:18.449]is that the slope or the annual rate of increase
[00:09:22.103]in different periods of time is changing dramatically.
[00:09:25.293]We are accelerating the amount of carbon dioxide
[00:09:28.200]increase into the atmosphere,
[00:09:31.226]and over the last decade,
[00:09:32.619]it's at a,
[00:09:34.598]it's a rate of more than two parts per million per year.
[00:09:38.444]So the slope here is much stronger
[00:09:41.247]than in earlier periods.
[00:09:43.187]In 1960 let's say,
[00:09:45.125]it was less than one part per million.
[00:09:47.676]And again, if we move this to the most recent data,
[00:09:52.070]I always like to look-up the most recent data,
[00:09:54.098]today, in early September,
[00:09:56.727]401 parts per million,
[00:09:58.807]and we're actually on the low slope,
[00:10:02.352]let's see if I can get this here,
[00:10:03.632]we're actually on the low point of this
[00:10:05.631]seasonal variation due to vegetation growth.
[00:10:11.224]So it's a big deal.
[00:10:13.264]400 parts per million is a very large number
[00:10:16.899]compared to where we've been.
[00:10:19.393]This particular group CO2 Earth
[00:10:22.236]is monitoring it all the time,
[00:10:24.748]on a daily basis you can go and check
[00:10:26.775]the latest amounts of carbon dioxide,
[00:10:30.453]crossing the threshold of greater than 400
[00:10:34.415]is really viewed as a very big significant change
[00:10:39.212]in our lifetime.
[00:10:41.533]Okay so I think that my audience here,
[00:10:43.957]based on our conversations earlier
[00:10:46.327]is very well-educated on all of this,
[00:10:48.039]but I'll quickly go through
[00:10:49.531]from a physical chemist perspective,
[00:10:52.270]what all this about.
[00:10:54.740]Why does it matter that we're adding
[00:10:56.730]so much carbon dioxide to the atmosphere,
[00:10:59.662]and why is that changing our world?
[00:11:03.218]So in brief,
[00:11:08.351]you know sunlight is impinging on the earth's atmosphere,
[00:11:10.760]a fraction of it about 30% is reflected
[00:11:15.366]off the outer parts of the atmosphere.
[00:11:19.448]About 20% is absorbed by the atmosphere,
[00:11:22.783]and importantly about 50% of this visible
[00:11:27.024]and ultra-violet radiation that's coming from the sun,
[00:11:30.868]is absorbed by earth's,
[00:11:32.829]by the earth itself,
[00:11:34.693]and re-radiated back towards the atmosphere.
[00:11:38.830]And so the light is absorbed,
[00:11:42.459]the analogy I often use it's like having a
[00:11:45.945]an asphalt road absorbing,
[00:11:50.666]a black asphalt road absorbing the heat,
[00:11:54.490]it's the sunlight that's coming from the sun
[00:11:56.239]and re-radiating it as heat,
[00:11:58.388]but in actual technical terms
[00:11:59.896]it's as infrared radiation.
[00:12:02.066]And that infrared light,
[00:12:04.234]much longer wavelength light is
[00:12:06.794]then re-radiated back into the atmosphere,
[00:12:11.288]and about 60% of it escapes but
[00:12:14.407]about 40% of it is trapped by greenhouse gases.
[00:12:21.867]So the general idea of,
[00:12:26.724]of this again is sunlight,
[00:12:30.092]which is, this is a spectrum of our sunlight,
[00:12:33.624]so the sun is very very hot,
[00:12:34.892]it's emitting radiation in the ultraviolet-visible region.
[00:12:40.297]This is not to scale in terms of intensity
[00:12:43.111]but just giving you the region of wavelengths of light
[00:12:47.159]that are important for sunlight hitting the earth,
[00:12:50.708]primarily in the UVA and visible regions of the spectrum,
[00:12:56.390]it's absorbed by the earth
[00:12:58.374]and the outgoing light,
[00:13:00.338]I tend to call it Earthlight,
[00:13:01.836]the re-emitted radiation
[00:13:03.804]is appearing in the infrared,
[00:13:06.697]and actually quite long wavelength in the infrared,
[00:13:08.499]and we'll look at that a little bit more as we go.
[00:13:12.168]So this natural process is fine,
[00:13:14.663]it actually makes the earth quite inhabitable,
[00:13:17.589]it makes the earth comfortable to live in,
[00:13:20.395]it's a natural process to have the balance
[00:13:25.987]of incoming radiation and outgoing radiation.
[00:13:31.400]The problem comes about by the trapping of heat
[00:13:37.426]in our atmosphere by certain gases,
[00:13:40.575]and let's start with the basics.
[00:13:42.396]Our atmosphere is primarily nitrogen and oxygen,
[00:13:45.674]some water vapor, carbon dioxide, methane,
[00:13:50.706]nitrous oxide and other gases.
[00:13:54.190]Also aerosols and many other things.
[00:13:58.113]So which gases contribute to this trapping of heat?
[00:14:03.937]And we're gonna,
[00:14:05.931]we'll show a little example of this
[00:14:06.968]but nitrogen and oxygen,
[00:14:09.932]the primary components of the atmosphere
[00:14:11.629]do not do this because they don't
[00:14:13.977]absorb infrared radiation.
[00:14:15.624]We'll speak specifically about that in a moment.
[00:14:18.539]But those molecules that do absorb,
[00:14:21.136]let's say carbon dioxide or methane,
[00:14:24.458]they absorb this outgoing radiation,
[00:14:27.810]they absorb the light,
[00:14:30.893]and then they re-emit that light
[00:14:32.780]and they re-emit it in every possible direction,
[00:14:36.075]some of which is redirecting back towards the earth,
[00:14:39.074]and so that energy is trapped.
[00:14:42.629]A more accurate actually description is
[00:14:46.258]that those molecules absorb the radiation,
[00:14:49.252]they collide with other molecules
[00:14:51.490]and that what was vibrational energy
[00:14:54.298]then gets converted into translational energy or into heat.
[00:14:59.311]And so we are actually heating up the gaseous molecules
[00:15:02.128]in the atmosphere by energy transfer
[00:15:04.607]from vibrational energy of the absorber
[00:15:08.634]into thermal energy, translational and thermal energy
[00:15:13.687]of the entire atmosphere.
[00:15:16.788]Okay so here's my little example.
[00:15:18.824]The student's that I'm teaching
[00:15:20.839]haven't thought about
[00:15:24.155]what it means for infrared radiation to start
[00:15:27.375]vibrationally exciting molecules,
[00:15:30.240]so our favorite molecule here is carbon dioxide,
[00:15:34.965]and carbon dioxide is polyatomic,
[00:15:37.566]a triatomic molecule, it has,
[00:15:39.374]and it has some characteristic vibrations
[00:15:43.439]that in the simplest possible way to describe
[00:15:46.237]are balls and springs,
[00:15:48.646]and depending on the spring constant
[00:15:51.864]and the mass of the balls,
[00:15:53.335]they ocellate at specific frequencies,
[00:15:56.114]and those are the characteristic frequencies
[00:15:58.754]that the light has to contain in order
[00:16:01.030]to cause them to vibrate.
[00:16:03.899]So we have a symmetric stretch,
[00:16:06.360]I'll show you these in a moment.
[00:16:07.451]We have an asymmetric stretch
[00:16:09.363]where one is extending and the other one is not,
[00:16:11.836]right one of my colleagues was always good at modeling
[00:16:14.049]these different vibrations.
[00:16:16.398]We have different kinds of bending motions
[00:16:18.791]and one of the things that I find quite interesting,
[00:16:20.787]it's the bends that are the most important
[00:16:23.891]in the atmosphere, these bending vibrations
[00:16:25.915]of carbon dioxide.
[00:16:27.829]So, but not all of these absorb infrared radiation.
[00:16:33.419]And so in particular the symmetric stretch is not
[00:16:37.928]infrared active so if you humor me,
[00:16:40.851]we're going to go to a little website,
[00:16:47.664]I think we had this running a little earlier, yup.
[00:16:52.187]Takes a second to come up.
[00:16:54.321]And we're going to pick on carbon dioxide,
[00:16:59.835]and we're going,
[00:17:00.979]this is the infrared, so if you're a,
[00:17:02.231]if you've taken chemistry classes
[00:17:05.378]or you would've seen an infrared spectrum
[00:17:07.953]at what frequencies or wavelengths
[00:17:10.155]in the infrared region does this molecule absorb?
[00:17:13.862]And if we click on one of these,
[00:17:16.300]for example the asymmetric stretch,
[00:17:19.359]a very very strong absorption,
[00:17:21.571]what you see, it's a very strong absorption,
[00:17:24.559]and this little arrow is really quite important,
[00:17:28.003]because this little arrow is showing
[00:17:30.188]how the charge distribution
[00:17:32.380]or for experts here the dipole moment,
[00:17:34.952]is changing as the molecule vibrates.
[00:17:39.034]And that's, and that's what allows it to absorb,
[00:17:43.043]interact with electric magnetic radiation,
[00:17:47.997]which is an oscillating electric field.
[00:17:51.090]In addition, the low frequency bends,
[00:17:55.605]which are the most important in the atmosphere,
[00:17:57.986]here's an example of one,
[00:18:00.238]one's in plain, one's out of plain.
[00:18:02.427]It's another strong absorber,
[00:18:04.661]we'll see in a few moments
[00:18:06.198]how it effects the spectrum,
[00:18:08.148]and again you can see that as this
[00:18:10.298]molecule is vibrating these little arrows
[00:18:12.165]are in indication of how the charge distribution
[00:18:15.184]ocellates as the molecule vibrates, and this,
[00:18:19.456]or the dipole moment changes,
[00:18:21.335]and this is absolutely critical for a molecule
[00:18:23.702]to be absorbing infrared radiation.
[00:18:27.999]And then if we go to the one that is seemingly missing,
[00:18:32.005]the symmetric stretching motion of the molecule,
[00:18:34.971]as the oxygen molecule,
[00:18:36.630]oxygen atoms pull ways symmetrically from the
[00:18:39.921]center of carbon atom.
[00:18:41.883]There's no absorption of infrared radiation,
[00:18:44.842]even though this molecule absorbs at other frequencies,
[00:18:48.802]because there is no change in the charge distribution
[00:18:52.336]or the dipole moment as the molecule absorbs.
[00:18:55.709]And the one that's gonna be most important
[00:18:58.048]for our purposes is this lower frequency bend,
[00:19:00.645]which (tongue clicking),
[00:19:02.804]these lower frequency bends which overlap
[00:19:05.058]beautifully with the emitted radiation,
[00:19:07.187]from the earth.
[00:19:09.904]Okay. Let's see if we can get out of this.
[00:19:15.366]Okay. So we spend in my class
[00:19:20.291]a considerable amount of time
[00:19:21.966]trying to explain changes in charge distribution,
[00:19:26.015]and why some molecules like carbon dioxide
[00:19:29.498]in certain vibrational motions absorb radiation.
[00:19:33.361]Of course nitrogen (N2) and oxygen (O2)
[00:19:36.318]do not absorb infrared radiation
[00:19:38.455]because they don't,
[00:19:40.440]their charge distribution does not change
[00:19:43.557]as they stretch.
[00:19:45.208]And therefore their,
[00:19:47.201]and technically their dipole moment doesn't change.
[00:19:50.160]Okay so this is the critical diagram
[00:19:55.910]indicating which molecules are actually
[00:19:58.464]effective greenhouse gases.
[00:20:00.784]So this green line that shown here is
[00:20:04.347]the emission that would be occurring from the earth
[00:20:08.917]if there were no atmosphere,
[00:20:10.618]it was just a vacuum and so the
[00:20:13.180]sunlight came into the earth,
[00:20:14.937]it was re-radiated as infrared
[00:20:16.936]and then there would be a characteristic,
[00:20:19.200]what's called blackbody spectrum,
[00:20:22.344]a characteristic of the earth's temperature.
[00:20:25.142]And it would be smooth and simple,
[00:20:28.707]it'd be peaked at long wavelength regions
[00:20:31.504]as you see here.
[00:20:33.126]But if you actually looking from outer space
[00:20:35.738]back through the earth's atmosphere,
[00:20:38.401]what you see is a spectrum of all of
[00:20:42.259]the absorbers that are present in the atmosphere.
[00:20:45.343]Methane, nitrous oxide, ozone,
[00:20:48.465]but most importantly carbon dioxide.
[00:20:51.530]Carbon dioxide, and these are the bends
[00:20:53.459]of the carbon dioxide,
[00:20:55.578]which happen to fall at exactly at the right wavelength
[00:20:58.796]or frequency, whichever way you want to think of it,
[00:21:01.578]right at the peak of the,
[00:21:04.244]of the outgoing radiation,
[00:21:08.721]coming from the earth.
[00:21:11.402]And so it's, that is why carbon dioxide
[00:21:14.047]is the most important absorber,
[00:21:17.364]or one of the most important absorbers
[00:21:19.692]in the greenhouse gases in the atmospheres.
[00:21:24.301]So it is, it is the molecules that are present,
[00:21:27.677]it's how strongly they absorb infrared light,
[00:21:30.938]and how well it matches with the outgoing emission
[00:21:35.669]from the earth, this blackbody radiation
[00:21:40.011]that is being emitted from the earth
[00:21:42.257]as the sunlight gets converted
[00:21:46.401]into broad infrared radiation.
[00:21:50.538]And so that's why CO2 (clears throat),
[00:21:55.127]water vapor and other gases (clears throat)
[00:21:57.455]are very important.
[00:21:59.621]Okay, so I take pride each time I teach this course,
[00:22:04.774]in going to the databases
[00:22:08.612]and these again another thing we would plod up in my class,
[00:22:11.832]and in Excel spreadsheet we would
[00:22:16.683]the concentrations of different gases
[00:22:20.363]in the atmosphere as a function of time.
[00:22:23.424]So carbon dioxide is (clears throat)
[00:22:29.153]we just said it's greater than 400 parts per million.
[00:22:31.618]And other important greenhouse gases are methane,
[00:22:38.086]coming in large part from animal emissions if you will.
[00:22:43.984]Nitrous oxide, another important greenhouse gas,
[00:22:47.336]and I have in boxes here,
[00:22:49.234]really trying to point out
[00:22:50.640]there's much much less of these gases.
[00:22:53.152]This is in parts per billion compared to carbon dioxide
[00:22:55.824]parts per million,
[00:22:57.680]but it's a very powerful absorber of infrared radiation,
[00:23:02.947]and so it turns out that less still contributes a lot.
[00:23:07.351]But I wanna focus our attention here for a second
[00:23:11.053]of a class of molecules that we often don't talk about,
[00:23:14.079]chlorofluorocarbons, they were big in the news
[00:23:16.858]when, with regard to the ozone hole over Antarctica,
[00:23:21.430]but they made the news last weekend,
[00:23:23.642]if you'd read the newspapers over the weekend,
[00:23:26.289]you would've read about hydrofluorocarbons,
[00:23:29.842]which were actually a replacement refrigerant
[00:23:33.061]and used in refrigerators and air conditioning
[00:23:37.373]as the coolant when,
[00:23:42.692]and they were a replacement to eliminate chlorofluorocarbons
[00:23:46.152]which had been shown to be inert
[00:23:48.288]that they were, and participate in removal of ozone
[00:23:53.489]from, and creating the ozone hole over Antarctica,
[00:23:57.623]I'm not gonna go into that subject
[00:23:59.012]but let's just focus on hydrofluorocarbons.
[00:24:01.529]It was a replacement and is actually a very strong
[00:24:05.496]greenhouse gas and you can see that very strong,
[00:24:10.143]this is in parts per trillion,
[00:24:11.949]so orders of magnitude less of these
[00:24:14.476]man-made, human made components,
[00:24:17.759]and growing in importance as it became a replacement
[00:24:24.155]Okay so last weekend,
[00:24:28.888]if you were watching the news,
[00:24:33.538]Carrie was in,
[00:24:34.863]representing the United States in Rwanda,
[00:24:37.255]and over the weekend there was an agreement made
[00:24:40.266]to bann the use of,
[00:24:42.899]bann the production of hydrofluorocarbons,
[00:24:45.978]so let's go back for a second,
[00:24:47.531]I don't know if I can do that here so easily,
[00:24:50.229]well anyway, let's not got back.
[00:24:51.994]Hydrofluorocarbons so now a known greenhouse gas,
[00:24:58.041]the world, let's see 170 countries agreed
[00:25:02.873]to eliminate the production of this
[00:25:11.367]which are typically being used
[00:25:13.075]in air conditioners and refrigerators.
[00:25:14.202]It's an amazing thing to have,
[00:25:16.042]a uniform agreement about this.
[00:25:19.155]Again most of this has originates in
[00:25:22.279]trying not to destroy our ozone layer
[00:25:27.075]but it turned out they're also
[00:25:29.525]very strong greenhouse gases,
[00:25:30.524]so as we try to engineer changes,
[00:25:32.578]sometimes we make further changes in our atmosphere.
[00:25:37.505]I think one of the interesting things is
[00:25:40.005]that, is the projection of how much this
[00:25:42.938]these particular class of molecules,
[00:25:46.563]hydrofluor, hydrofluorocarbons, (chuckling)
[00:25:50.688]impacts in climate change as well.
[00:25:54.154]It was predicted to have the equivalent of 70 gigatons
[00:25:58.432]of carbon dioxide, I'll talk about these numbers
[00:26:01.081]a little bit more in a moment,
[00:26:02.323]or twice the amount of carbon dioxide
[00:26:05.907]that would be produced annually,
[00:26:07.885]and it's thought to,
[00:26:09.540]it's thought that by eliminating this, these,
[00:26:12.006]this class of molecules,
[00:26:14.015]we're going to prevent a half of,
[00:26:16.669]a half a degree centigrade of warming in this century.
[00:26:21.561]So why are such a small amount
[00:26:24.061]of these molecules important?
[00:26:25.841]These hydrofluorocarbons are a thousand times
[00:26:28.819]more heat trapping than carbon dioxide
[00:26:33.577]so really remarkable and remarkable
[00:26:35.994]that a global treaty could be agreed upon,
[00:26:38.960]'cause as you'll see we've been trying to
[00:26:41.098]have a treaty on reduction of,
[00:26:43.316]of carbon dioxide and it's taken a very,
[00:26:47.264]very long time to get there.
[00:26:48.945]Okay so the Intergovernmental Panel on Climate Change,
[00:26:53.301]every decade puts out a report.
[00:26:58.757]This is the one from 2012,
[00:27:00.649]basically identifying the molecules,
[00:27:04.884]the species that are being emitted
[00:27:07.651]into the atmosphere and they're by humans,
[00:27:10.448]anthropogenic by humans,
[00:27:12.472]and their impact on this radiative balance
[00:27:16.072]that of the earth.
[00:27:17.935]So in terms of the ones that are most important,
[00:27:20.783]carbon dioxide, methane, nitrous oxide, carbon monoxide,
[00:27:24.239]non-methane volatile organic compounds.
[00:27:27.709]Another big one that's important,
[00:27:31.371]are, is black carbon soot emission if you will,
[00:27:36.081]from again coming from incomplete combustion,
[00:27:41.134]and then there are some species
[00:27:44.324]that have the opposite effect.
[00:27:47.469]If you have aerosols or particles in the atmosphere,
[00:27:51.155]they reflect sunlight and reduce the amount.
[00:27:54.830]So pollution in China for example,
[00:27:57.492]with a strong haze over the environment
[00:28:00.160]has the opposite effect because there's large amounts
[00:28:03.218]of aerosols that are reflecting light.
[00:28:07.508]They will have a future challenge.
[00:28:09.680]And so the brown bar here at the end
[00:28:13.431]is the accumulative effect of all these things,
[00:28:15.764]but the part that you should notice,
[00:28:18.193]particularly if you're a scientist here,
[00:28:20.408]are the error bars.
[00:28:22.552]How much uncertainty are in some of these numbers?
[00:28:25.408]And one of the big,
[00:28:27.121]the big ones are actually not in terms,
[00:28:29.364]we are a very good at measuring carbon dioxide
[00:28:31.463]and methane in the atmosphere,
[00:28:33.427]and some other species,
[00:28:35.087]but the influence and the impact of particles,
[00:28:37.943]black carbon, soot, organic carbon, aerosol,
[00:28:41.871]have huge error bars and those contribute
[00:28:44.544]to making large error bars in our ability
[00:28:47.301]to predict the influence of this group of molecules
[00:28:51.523]in affecting our climate.
[00:28:56.090]So if I were a student sitting in the audience
[00:28:58.410]and thinking about what my major should be
[00:29:00.339]or what career track I might like to take,
[00:29:02.940]there are real opportunities
[00:29:05.159]for scientists and for going forward
[00:29:09.995]and there in this bottom half of this graph, okay?
[00:29:14.325]So, of course,
[00:29:19.642]the amount of these gases in the atmosphere
[00:29:21.425]come from natural sources and also,
[00:29:23.644]a lot of it comes from natural sources
[00:29:26.343]and of course we're adding to it by anthropogenic
[00:29:31.161]or human activities.
[00:29:32.729]The natural sources of course is
[00:29:34.490]every time we breathe in oxygen,
[00:29:35.947]we're expelling carbon dioxide,
[00:29:37.504]and luckily plants and trees,
[00:29:39.453]and this is important,
[00:29:40.823]are undergoing photosynthesis all the time,
[00:29:44.086]and fixate, fixing that,
[00:29:46.419]removing carbon dioxide and turning them into fixed carbon.
[00:29:50.596]And we'll show this and discuss this in a moment
[00:29:52.762]because as we,
[00:29:54.962]as we have extensive deforestation of our environment,
[00:30:01.092]this process becomes,
[00:30:03.515]this channel becomes smaller and has an impact.
[00:30:07.956]The oceans play a role.
[00:30:10.407]I'll discuss some of this in a moment.
[00:30:13.159]But the primary human activities
[00:30:15.179]or the primary anthropogenic activities
[00:30:17.533]that are effecting the amount of carbon dioxide
[00:30:19.927]in the atmosphere boil down to
[00:30:22.712]burning of fossil fuels and deforestation.
[00:30:27.149]So let's take a look at that in more detail.
[00:30:32.042]I think the numbers are sort of staggering.
[00:30:35.603]The amount of emissions of,
[00:30:40.024]of carbon dioxide, human, anthropogenic,
[00:30:42.938]carbon dioxide emissions
[00:30:44.692]in gigatons of carbon dioxide per year,
[00:30:47.859]come from two sources,
[00:30:50.750]and this is shown as a function of time,
[00:30:53.714]from forestry and other land uses, okay?
[00:30:57.902]And changes in our land use
[00:31:01.567]and this enormous growth,
[00:31:05.229]oops, don't know if I am good at going back,
[00:31:08.410]oh there we go, okay.
[00:31:10.401]And this enormous growth in the
[00:31:13.281]amount of carbon dioxide emissions
[00:31:15.514]coming from burning of fossil fuels
[00:31:17.373]and processing of cement.
[00:31:19.364]I think that's really quite amazing,
[00:31:21.371]and flaring from methane,
[00:31:24.959]burning off methane and other bi-products
[00:31:27.702]in industrial uses.
[00:31:30.175]Mostly from power plants,
[00:31:32.555]and it's the dramatic slope,
[00:31:34.817]the change in the slope that's amazing.
[00:31:37.735]So how many gigatons?
[00:31:39.150]A gigaton is a billion,
[00:31:42.592]is that right?
[00:31:43.722]Giga is a billion,
[00:31:45.123]a billion tons of carbon dioxide per year,
[00:31:47.446]these are enormous numbers.
[00:31:50.879]So a thousand gigatons of carbon dioxide were added
[00:31:56.164]from 1850 to 2000.
[00:31:59.323]And then half that amount again was added in just 15 years.
[00:32:05.022]I think these numbers are just staggering to me,
[00:32:07.344]and how much more would we need to add,
[00:32:10.115]or would we be able to add,
[00:32:11.899]and be safely not impacting our environment?
[00:32:15.888]Current estimates are only about another 335 gigatons,
[00:32:20.488]or about another eight years of
[00:32:22.322]emission at our current rate.
[00:32:23.969]That's a lot of,
[00:32:26.024]that brings it home to me
[00:32:28.064]that things are changing rapidly.
[00:32:33.693]Okay so how we doing here?
[00:32:35.937]And that what happens to that carbon dioxide emission?
[00:32:39.190]I think that most of us understand that
[00:32:41.557]where is it come from?
[00:32:44.269]It comes from burning of fossil fuels,
[00:32:46.082]more than 90%,
[00:32:47.984]it comes from deforestation,
[00:32:49.780]changes on our land use,
[00:32:50.959]and some of it ends up in the atmosphere,
[00:32:54.840]and that's the part that we're measuring.
[00:32:56.814]We're only measuring the amount of carbon dioxide
[00:32:59.099]in the atmosphere but that's only
[00:33:00.500]44% of the total emissions,
[00:33:03.023]the rest of it's going into tremendous
[00:33:06.438]growth of plants and trees,
[00:33:08.062]as they accommodate that.
[00:33:09.852]And the biggest unknown actually is in the ocean.
[00:33:13.402]We are, up till now, the ocean is responding well
[00:33:16.663]and absorbing and becoming acidified
[00:33:19.184]as it absorbs carbon dioxide
[00:33:21.590]and making carbonic acid
[00:33:23.380]and accommodating but one of the biggest unknowns
[00:33:26.673]is how much longer the ocean is going to be
[00:33:29.331]able to accommodate all of this excess
[00:33:31.258]carbon dioxide that we're putting into the atmosphere.
[00:33:34.302]So what we measure is only about 40% of the amount
[00:33:39.583]that's totally being emitted.
[00:33:44.171]Here's more detail,
[00:33:45.380]I don't really wanna go into
[00:33:47.180]tracing these sources and syncs
[00:33:49.465]over a longer period of time,
[00:33:50.851]but I do wanna emphasize variability
[00:33:53.020]and the fact that we're really not
[00:33:56.019]in a very good position of predicting.
[00:33:57.416]As time goes on,
[00:33:58.541]it looks like ocean,
[00:34:00.414]let's just take ocean for example.
[00:34:01.718]It looks like the ocean just continues
[00:34:04.084]to be able to accommodate
[00:34:05.408]the increasing amount of carbon dioxide
[00:34:08.024]but there is a lot of sense
[00:34:09.738]that this is a temporary thing,
[00:34:12.538]and that the oceans will be acidified
[00:34:15.061]that they will be accommodating,
[00:34:17.575]and there could be a dramatic change
[00:34:20.100]in the amount of atmospheric carbon dioxide,
[00:34:22.177]at a time when,
[00:34:24.477]the oceans are accommodating less.
[00:34:29.905]Okay so we're putting all this carbon dioxide
[00:34:32.424]into the atmosphere and,
[00:34:35.373]and we're observing in parallel
[00:34:38.477]an increase in temperature over,
[00:34:41.731]and this is temperature over land.
[00:34:44.287]And I like to tell this story,
[00:34:47.672]so I don't know how many of you know this group,
[00:34:49.634]Berkeley Earth, but they were actually
[00:34:50.758]a bunch of pessimists about the correlation
[00:34:53.512]between carbon dioxide and temperature increase.
[00:34:56.530]They thought you know,
[00:34:58.453]we just, we're not really sure we believe
[00:35:00.160]the data analysis that's been done.
[00:35:02.502]Maybe, maybe these governmental agencies,
[00:35:05.039]you know they really haven't done proper statistics,
[00:35:12.277]And so in the last maybe half a dozen years,
[00:35:15.528]this group, reanalyzed essentially
[00:35:19.307]all of the temperature data,
[00:35:21.596]particularly land, over land regions.
[00:35:24.350]Coming from NASA, NOAA, Hadley,
[00:35:27.498]and then their own assessment,
[00:35:29.599]which is this gray, gray trace here.
[00:35:32.190]So this is,
[00:35:34.164]a smooth 10-year moving average
[00:35:36.960]with 95% uncertainty intervals indicated by gray,
[00:35:41.923]but you can see that their conclusion was
[00:35:45.541]I think to their surprise,
[00:35:47.088]that the temperature record was really rather consistent
[00:35:50.308]between measurements that were made by
[00:35:53.504]three different agencies,
[00:35:56.076]showing that the temperature was
[00:35:58.479]increasing pretty dramatically
[00:36:00.636]in the most recent times.
[00:36:06.477]A 1.5 degree centigrade over the past 250 years,
[00:36:09.099]and in about less than, a little less
[00:36:13.284]than a degree centigrade in the past 50 years,
[00:36:16.159]and I'll show you these numbers
[00:36:17.701]a little bit more carefully in a moment.
[00:36:19.596]But one of things that this group did,
[00:36:21.237]which I thought was rather interesting,
[00:36:24.035]again for a group of skeptics,
[00:36:26.383]there was a lot of discussion going on.
[00:36:28.350]Why, why, what's causing the bumps in this graph,
[00:36:32.276]and how well correlated is it
[00:36:34.464]with the amount of carbon dioxide
[00:36:36.416]we've put into the atmosphere?
[00:36:38.565]And so they did a model,
[00:36:39.960]so the black is,
[00:36:41.682]is their analysis of carbon dioxide,
[00:36:44.598]a temperature change over land,
[00:36:47.502]I'm sorry, over this long period of time,
[00:36:50.192]and the red is a model
[00:36:53.162]that they developed to
[00:36:56.469]predict temperature changes based on
[00:36:58.648]just two factors.
[00:37:00.527]Volcanic activity, because when volcanoes explode
[00:37:03.771]the temperatures, there's a lot of particles
[00:37:06.943]going into the atmosphere and the temperature decreases
[00:37:09.656]so each of these strong dips here,
[00:37:12.021]are due to known volcanic activity,
[00:37:16.542]and the only other factor that they put into their model
[00:37:19.722]was increasing carbon dioxide emission,
[00:37:22.907]so this red trace that you're looking at
[00:37:25.330]is based on two factors,
[00:37:27.500]volcanoes and human,
[00:37:29.444]increases the human greenhouse gas emissions.
[00:37:32.828]And it very well reproduces the temperature changes
[00:37:37.364]that have occurred in the last 250 years.
[00:37:42.534]I think this is important because
[00:37:44.484]a lot of skeptics and including this group let's say,
[00:37:48.427]felt what about solar variations
[00:37:52.301]or solar flares or other effects
[00:37:55.123]that were going on?
[00:37:56.276]Could be that be important in describing this?
[00:37:59.126]And I think the,
[00:38:00.684]their conclusions again,
[00:38:02.363]this is Berkeley Earth,
[00:38:04.223]and I think if you go back and look at it
[00:38:06.328]very much skeptics to begin with
[00:38:09.273]that the correlation between
[00:38:12.595]greenhouse gas emissions
[00:38:13.859]and temperature was going to be so strong.
[00:38:19.004]So this is the best data I could find,
[00:38:21.460]of the, a running average of the global surface temperature,
[00:38:26.955]from 1880, average, so an average between 1880 and 1920,
[00:38:33.472]and then relative to that number.
[00:38:36.257]So zero is in the pre-industrial era, and
[00:38:42.714]and it's different,
[00:38:44.693]different averaging done of the data,
[00:38:47.497]but 2015 represents relative to that mean,
[00:38:52.578]an increase of more than one degree centigrade,
[00:38:54.864]more than 2.1 degree Fahrenheit rise
[00:38:57.699]in the temperature over the surface of the earth.
[00:39:02.147]And if people,
[00:39:04.808]this is where statistics some in,
[00:39:06.582]if you just wanna do a linear fit since 1970,
[00:39:09.670]there's more than one degree centigrade change.
[00:39:13.134]And what climate scientists
[00:39:15.090]and atmospherics chemists believe is
[00:39:17.039]that we can accommodate at most,
[00:39:19.918]a two degree centigrade rise without having
[00:39:23.016]irreparable damage to the earth
[00:39:25.218]and frankly they'd like to keep it at 1.5,
[00:39:27.397]and we're already at more than one.
[00:39:29.001]So it's really scary to me.
[00:39:34.121]How hot is it?
[00:39:35.665]So you know every year, in recent times,
[00:39:38.198]we have newspaper headlines talking about how hot,
[00:39:42.940]how much temperature change there
[00:39:44.903]has been more recently than previously.
[00:39:47.109]So this graph shows the global surface temperature,
[00:39:51.364]average from, averaged,
[00:39:56.488]so deviations from the 20th century average,
[00:39:59.198]so here is our average,
[00:40:00.704]and now we're looking at deviations from the, up till,
[00:40:05.526]so an average from 1900 to 2000,
[00:40:09.543]and then deviation from that.
[00:40:11.441]Well if you look at the red,
[00:40:14.103]clearly the red is in recent times
[00:40:16.503]and the 15 hottest years are since 2001.
[00:40:22.916]You know we see this on our headlines all the time.
[00:40:25.061]I think this is another nice graph.
[00:40:26.869]The number of days above 100 degrees Fahrenheit,
[00:40:30.281]so this was done in July,
[00:40:33.287]August of this year,
[00:40:35.882]it was made the newspaper that July 2016
[00:40:39.166]was one of the hottest ever
[00:40:41.644]and so they, this a surface map
[00:40:44.992]showing regions of the United States,
[00:40:47.589]and the coloring indicates the numbers of days
[00:40:51.403]above 100 degrees Fahrenheit.
[00:40:53.053]Let's just focus on the red.
[00:40:54.447]Okay, right in here.
[00:40:55.445]The number, this is 50 more,
[00:40:57.121]50 or more days over 100 degrees Fahrenheit.
[00:41:01.279]That was between 1991 and 2010,
[00:41:04.259]over the last 20 years.
[00:41:05.571]50 years from now,
[00:41:08.320]look at the amount of red,
[00:41:10.381]the number of regions of the United States
[00:41:13.398]that'll have more than 50 days
[00:41:15.575]of over 100 degree temperature, Fahrenheit temperature.
[00:41:21.401]Okay so as you might imagine
[00:41:23.183]and recognize the temperature variation
[00:41:27.579]is not uniform everywhere in the,
[00:41:30.714]on the earth.
[00:41:31.867]Most of the studies or most of the data
[00:41:35.250]is being recorded over land masses,
[00:41:37.245]less over the oceans but now there's uniform coverage
[00:41:39.789]and the models are really quite good,
[00:41:42.065]but the greatest warming, in,
[00:41:46.941]of the mean surface temperature,
[00:41:50.538]this is for 2014 relative to 1960 to 1990 average,
[00:41:55.784]is, is over the Arctic region.
[00:41:59.956]It's the red is in the Northern Hemisphere,
[00:42:02.152]over the Arctic region,
[00:42:04.727]and there are variations in temperature
[00:42:07.079]across the earth.
[00:42:08.398]Again, this is,
[00:42:09.797]I guess this is from Berkeley Earth as well,
[00:42:10.997]but we see these often.
[00:42:12.539]Okay, so it's warming and it's not uniform,
[00:42:17.473]and where it's not uniform,
[00:42:19.205]it's really warming, really quite fast,
[00:42:21.312]and the world is changing.
[00:42:23.381]So the Arctic is heating up twice as quickly
[00:42:26.138]as the rest of the planet,
[00:42:27.301]and this can be seen in the extent of Arctics
[00:42:31.953]sea ice or the reduction in the amount of Arctic sea ice,
[00:42:35.312]particularly at the end of the summer.
[00:42:37.818]And so over a recent history from 1980
[00:42:42.711]and going to 2015 you can really see
[00:42:46.481]a dramatic 40% decrease in the amount of
[00:42:50.424]summer sea ice coverage,
[00:42:52.464]just over the last 35 years.
[00:42:56.413]So it is observable,
[00:42:58.606]it's just whether we want to look, I guess.
[00:43:03.138]I was in Switzerland last summer and,
[00:43:05.513]looking at the glaciers there
[00:43:09.209]and how rapidly they're melting,
[00:43:11.258]so the right-hand graph here is
[00:43:13.437]an indication of,
[00:43:15.932]in blue the annual loss per year of glacier mass
[00:43:20.173]and in brown the cumulative loss
[00:43:23.710]and the trend of receding glaciers,
[00:43:27.075]an important source of water to many places.
[00:43:30.361]And a corresponding increase in global sea levels.
[00:43:34.498]This particular article pointed to 75%
[00:43:38.846]of the rise in sea level in the past century
[00:43:41.436]coming from glacier melt.
[00:43:46.380]Okay so what are we gonna do about it?
[00:43:49.113]And who's responsible and
[00:43:51.133]what countries need to be on board?
[00:43:56.514]So this is the carbon dioxide emissions
[00:43:59.378]since 1960 by country.
[00:44:03.818]And I remember teaching this class in 2005
[00:44:07.348]when the US,
[00:44:09.144]so if you look at this the US
[00:44:10.748]was the largest emitter of carbon dioxide emissions
[00:44:16.431]But beginning in 2005 and going forward,
[00:44:20.173]China, this exploding economy and growth in China
[00:44:24.513]in population and in industrialization
[00:44:27.515]has led to this just dramatic increase in emissions,
[00:44:31.555]carbon dioxide emissions from China.
[00:44:34.835]So it is now, the dominant,
[00:44:37.379]the largest source of carbon dioxide emissions in the world.
[00:44:42.853]So we have China, we have US,
[00:44:44.740]the EU, the European Union,
[00:44:47.457]they through conservation efforts,
[00:44:50.332]have really reduced their emissions,
[00:44:51.953]really for, you know,
[00:44:54.171]some time now, reducing their
[00:44:57.596]carbon footprint if you will.
[00:45:00.928]And India, another growing economy,
[00:45:03.107]making another important contribution,
[00:45:05.909]and with large growth,
[00:45:07.488]so again I emphasize that the scientist in me
[00:45:10.263]is not just looking at the numbers
[00:45:12.507]of where we are today,
[00:45:14.187]but the slope, the rate of change of these numbers.
[00:45:21.029]Okay so where are we?
[00:45:23.471]So, last November,
[00:45:25.896]well almost two years ago now,
[00:45:28.155]I thought it was remarkable
[00:45:30.304]that the US and China agreed to do something about this.
[00:45:34.376]Recognizing that if the US decided to
[00:45:40.552]reduce its greenhouse gas emissions
[00:45:43.394]but China did nothing,
[00:45:44.890]it wouldn't matter.
[00:45:46.153]I mean what was the point in us sacrificing if,
[00:45:47.939]if it wasn't a worldwide commitment.
[00:45:50.573]And similarly if China made an increased effort
[00:45:56.395]made an effort to reduce greenhouse gas emissions,
[00:45:59.411]what difference would it make,
[00:46:00.863]if the US, the second largest producer did nothing?
[00:46:04.205]And so it really,
[00:46:06.497]I thought really was quite significant that
[00:46:09.294]just less than two years ago,
[00:46:13.559]and in this photo documenting Obama and Carrie
[00:46:17.960]were in China and the two largest
[00:46:21.126]carbon emitters, carbon polluters if you will,
[00:46:24.762]made it a first global agreement to reduce
[00:46:27.862]their carbon footprint,
[00:46:29.963]to reduce their emissions.
[00:46:32.672]And this really has been the beginning
[00:46:34.986]of a major policy change worldwide
[00:46:37.742]for dealing with this very significant
[00:46:41.566]growth in greenhouse gases.
[00:46:45.478]And so I'm nearly at the end of my talk,
[00:46:47.639]and this is again right out of the headlines.
[00:46:52.382]This has been a fund,
[00:46:53.461]I don't know if you've been following it as I have,
[00:46:55.637]so in, in December of last year,
[00:47:01.153]there was the United Nations Framework Convention
[00:47:05.103]on climate change, met in Paris,
[00:47:07.179]always nice to meet in Paris, (laughing)
[00:47:09.698]and laid out a framework for
[00:47:17.103]a global reduction in,
[00:47:19.997]in carbon dioxide emissions
[00:47:22.279]and a goal of eliminating
[00:47:24.882]all net carbon pollution by 2100.
[00:47:27.903]So this is all very very recent.
[00:47:30.537]So, what was their goal?
[00:47:31.784]Their goal was to stay below what people believe
[00:47:35.134]as a really serious limit.
[00:47:36.924]To keep the temperature rise of the earth,
[00:47:39.176]global average temperature to less than
[00:47:42.369]a two degree centigrade increase above
[00:47:47.096]But really they'd like to keep it
[00:47:48.820]below 1.5 degrees centigrade.
[00:47:50.875]As I said we're well over
[00:47:52.233]one degree centigrade already, change.
[00:47:53.766]And to begin implementing these changes
[00:47:58.462]as soon as possible,
[00:48:00.374]and to increase,
[00:48:02.638]reduce our emissions significantly,
[00:48:08.447]And so in December of,
[00:48:12.472]so in December of 2015, the,
[00:48:15.651]the agreement they came to,
[00:48:17.982]which was really no action whatsoever,
[00:48:19.430]they said 55 countries need to agree to this,
[00:48:22.858]and those 55 countries need to account
[00:48:25.486]for at least 55% of the global emissions,
[00:48:28.842]in order for this agreement we're making today
[00:48:30.939]to be ratified.
[00:48:34.854]And if you look at the map underneath,
[00:48:37.048]I grabbed this just this last week,
[00:48:40.463]you can see the orange countries have bought in,
[00:48:44.724]and the green countries have not yet bought in
[00:48:47.298]to ratifying this agreement.
[00:48:50.694]And so over the last just two months,
[00:48:54.794]it's been fun to watch country after country,
[00:48:58.017]so the US agreed in September,
[00:49:00.339]China agreed in September,
[00:49:01.872]India in October,
[00:49:04.738]and just in the last weeks,
[00:49:09.010]it still is October isn't it, right, okay? (laughing)
[00:49:11.028]So this month,
[00:49:13.226]India agreed and now the European Union agreed to
[00:49:18.117]this, the Paris agreement,
[00:49:20.699]and so now all in total 75 countries
[00:49:24.159]have ratified this agreement
[00:49:25.879]and those 75 countries account for
[00:49:28.296]more than 60% of the global emissions.
[00:49:32.095]And so as result of that,
[00:49:34.283]this Paris Accord,
[00:49:35.817]which was a framework established just a year ago,
[00:49:39.819]in December 2015 will go into force,
[00:49:43.250]in November, just in a few weeks,
[00:49:47.792]two weeks, three weeks.
[00:49:49.422]Will be a binding agreement and I guess
[00:49:52.623]I was reading a little bit
[00:49:53.966]given the US politics,
[00:49:55.018]actually we can't get out of this.
[00:49:56.499]We're in it for at least three years by the way,
[00:49:59.320]it's not, it's not,
[00:50:00.785]you know, we can't, we cannot back out,
[00:50:02.704]so anyway we're committed
[00:50:04.747]to reducing carbon emissions.
[00:50:06.646]Whether we'll do it fast enough,
[00:50:09.182]well only who knows,
[00:50:10.212]and that's really for the students
[00:50:11.757]to be worrying about I think the most.
[00:50:14.676]So where'd this information come from
[00:50:17.321]and what can you read if you wanna know more?
[00:50:19.661]I think it's this,
[00:50:24.734]IPPC, the Intergovernmental Panel on Climate Change
[00:50:29.516]does an amazing job of assessing all of the data,
[00:50:33.800]it's particularly as a scientist,
[00:50:36.141]the physical base,
[00:50:37.871]the physical science basis for all of this is
[00:50:40.460]beautifully summarized in this 2013
[00:50:43.051]Working Group Report.
[00:50:45.207]There are lots of links here
[00:50:47.519]that one could turn to.
[00:50:48.862]Their conclusions in 2013,
[00:50:52.794]"The warming of this climate system is unequivocal,
[00:50:56.031]"we have made changes to our environment,
[00:50:59.299]"and it can be seen in temperature rises,
[00:51:02.165]"the amount of snow and ice,
[00:51:04.295]"sea levels rising,
[00:51:05.764]"and the obvious concentration
[00:51:08.300]"of greenhouse gas emissions".
[00:51:12.477]The human influence is clear,
[00:51:14.845]it's particularly evident from
[00:51:17.983]the greenhouse gas emissions
[00:51:20.045]and the observed warming of our climate.
[00:51:24.955]And then lastly,
[00:51:25.998]you know if we continue on current track,
[00:51:30.777]it's only gonna lead to further warming
[00:51:32.835]and further change
[00:51:35.271]and that the only course really is
[00:51:36.923]a reduction in our greenhouse gas emission.
[00:51:40.857]So, this is to entertain you for a moment,
[00:51:45.101]as we wind down here,
[00:51:46.799]an artistic impressionist view of
[00:51:50.220]what we're doing to our environment,
[00:51:52.442]burning fossil fuels for electricity,
[00:51:55.561]we're putting out a tremendous amount of carbon dioxide,
[00:51:58.121]deforestation of our forests,
[00:52:01.691]extensive development of,
[00:52:04.702]of cattle, growth in cattle
[00:52:09.417]and their emissions,
[00:52:11.538]we're acidifying the oceans,
[00:52:13.016]we're removing coral,
[00:52:15.220]I don't know, we could go on and on.
[00:52:17.380]Wind alone is not gonna solve it,
[00:52:19.828]we need new technologies,
[00:52:21.719]we need new investments,
[00:52:23.433]we need batteries,
[00:52:24.582]we need lots of things.
[00:52:26.059]And there's lots and lots of opportunities
[00:52:28.744]for young people starting their careers today
[00:52:32.314]to impact on and find solutions.
[00:52:35.227]So I wanna leave you with a bunch of questions,
[00:52:40.234]that this was also published in the New York Times,
[00:52:44.834]not long ago,
[00:52:46.136]that you might think about,
[00:52:48.377]or I might pose,
[00:52:49.902]which I'm not gonna answer unless you want me to,
[00:52:52.108]but I think we should all be thinking about,
[00:52:54.109]I tried to answer how much is the planet warming up,
[00:52:56.347]but the questions are,
[00:52:58.365]how much trouble are we in?
[00:53:00.014]Is there anything you personally can do?
[00:53:02.429]What's the optimistic scenario?
[00:53:04.362]What's the worse case scenario?
[00:53:06.601]Well okay, first of all I think
[00:53:09.407]I should answer one.
[00:53:10.405]Is there anything I can do?
[00:53:11.494]You should stop flying in airplanes.
[00:53:13.061]Okay I just flew here yesterday,
[00:53:14.640]you should stop flying in airplanes, (laughing)
[00:53:16.276]there one of the worst things you can do right?
[00:53:18.462]We use a lot of energy to fly.
[00:53:20.831]Will reducing meat in my diet,
[00:53:25.262]if you become a vegetarian,
[00:53:26.322]will you help the climate?
[00:53:27.396]We think that a tech breakthrough,
[00:53:30.320]will a tech breakthrough solve our problems?
[00:53:32.888]How much will the sea's rise?
[00:53:35.751]Should you live in Florida by the way, or on the Coast?
[00:53:38.290]Are the predictions reliable?
[00:53:41.738]Are climate scientists and physical scientists
[00:53:45.385]able to measure things accurately
[00:53:48.139]and make reliable predictions?
[00:53:50.132]You see I was not extrapolating,
[00:53:52.005]I was only showing where we are.
[00:53:53.753]What the whole heck is going on?
[00:53:57.731]Why do people think this isn't true, okay? (laughing)
[00:54:00.523]So that's one of things I have a hard time with.
[00:54:02.164]Is weather correlated with climate change?
[00:54:07.571]Who will benefit?
[00:54:08.805]Well I think Canada's gonna benefit okay?
[00:54:11.686]We should all invest in Canadian property soon right?
[00:54:18.588]Should we be hopeful?
[00:54:21.119]How does agricultural here in Nebraska
[00:54:23.176]and other places effect climate change,
[00:54:25.307]and how does climate change
[00:54:29.426]Will the sea's rise evenly?
[00:54:31.781]Is is really all about carbon?
[00:54:35.097]And so you know, if we click on this,
[00:54:37.157]there's lots of answers
[00:54:40.800]and maybe you know we can either pose the questions,
[00:54:43.321]so there's lots of questions that one can ask,
[00:54:46.574]and I guess it's up to you to decide
[00:54:49.173]where we go from here.
[00:54:50.601]Do we want to, oops,
[00:54:54.674]click on the right button here, okay.
[00:54:58.327]So I wanna thank you for listening to what I have to say.
[00:55:00.752]Tomorrow all on science,
[00:55:02.543]tonight a little bit about
[00:55:04.966]what are the scientific facts
[00:55:06.121]about at least they way I see them,
[00:55:07.635]the scientific data saying
[00:55:09.798]about our changing climate,
[00:55:12.319]our changing world,
[00:55:13.511]and I thank you for the opportunity to visit here
[00:55:16.209]and I'm happy to discuss your questions
[00:55:18.734]and hopefully you have some answers too,
[00:55:21.381]so thanks very much.
[00:55:23.689]Is most of your data
[00:55:25.514]from the Northern Hemisphere?
[00:55:26.917]I believe that the
[00:55:29.493]that they're monitoring,
[00:55:32.737]we can actually go and look it,
[00:55:34.968]but I believe they are monitoring,
[00:55:37.138]monitoring uniformly around the world.
[00:55:38.985]I think one of the problems is
[00:55:40.052]is it's been easier to do monitoring
[00:55:41.534]over land than over ocean,
[00:55:43.864]and so there's actually more,
[00:55:46.389]if you will a finer grid of data over land,
[00:55:48.567]than there is over ocean,
[00:55:50.458]but I think that,
[00:55:51.801]so that's a little bit of an issue but
[00:55:54.518]there's been more extensive monitoring now,
[00:55:57.544]uniformly around the world.
[00:56:00.597]So you mean global,
[00:56:13.896]You talked so well about
[00:56:15.896]something I've been aware of
[00:56:17.868]and you explained it so well.
[00:56:18.963]The dipole moment shift in the bend
[00:56:21.030]in the carbon dioxide molecule.
[00:56:22.709]I've always been under the impression
[00:56:24.735]that water vapor however, was just as efficient
[00:56:28.696]Could you explain how that,
[00:56:30.188]the dipole moment works with the H2O molecule,
[00:56:32.701]and whether it is more efficient
[00:56:34.836]or is that not accurate?
[00:56:37.134]Water is a really important greenhouse gas and,
[00:56:40.870]And that is water vapor.
[00:56:42.591]It is, let's see if I can get out of this.
[00:56:47.918]How do I escape out of here?
[00:56:49.552]Not so well, okay.
[00:56:50.550]So let's see what we can do here.
[00:56:54.358]Let's take a look at water,
[00:56:59.058]take me a second to bring it up.
[00:57:00.299]Okay so first of all,
[00:57:01.452]why don't we talk about water as a greenhouse gas.
[00:57:03.869]It's because there's only so much water vapor
[00:57:07.633]that the atmosphere can accommodate
[00:57:09.790]and then after that, it rains.
[00:57:12.160]So, it's not quite the same as a continual build-up,
[00:57:17.364]and one of the things I think I didn't point out,
[00:57:19.481]and one of the unknowns of course with carbon dioxide,
[00:57:22.734]is just how,
[00:57:24.018]how long the gas stays in the atmosphere,
[00:57:27.610]and it certainly stays in the atmosphere a long time.
[00:57:29.690]Hundreds of years.
[00:57:31.870]Okay so here is water vapor,
[00:57:33.701]and water is a bench molecule,
[00:57:36.023]and so water, all of its vibrations are
[00:57:39.773]actively absorbing radiation.
[00:57:44.092]So here you can see the dipole moment
[00:57:46.420]or the charge distribution of the water molecule changing,
[00:57:49.051]as it bends and also as it stretches.
[00:57:53.871]Even as it does this symmetric stretch
[00:57:56.179]that I have shown here.
[00:57:58.537]And then there's another asymmetric stretch
[00:58:00.994]right near it,
[00:58:02.077]so all of the vibrations of the water molecule are active.
[00:58:05.214]But what happens is there's sort of a limiting
[00:58:08.182]amount of water vapor that can be in the atmosphere
[00:58:10.855]at a given temperature,
[00:58:12.264]and therefore, and after that it rains out,
[00:58:14.434]whereas carbon dioxide, it's a very strong absorber,
[00:58:17.542]but we keep on putting more and more and more,
[00:58:20.096]and the concentration is not limited in any way
[00:58:22.416]or the same sort.
[00:58:23.844]Again, it is being accommodated in the oceans,
[00:58:26.952]right, and it's acidifying the oceans
[00:58:30.162]but it's not,
[00:58:33.867]but we're still putting in so much excess
[00:58:36.000]that the atmospheric concentration
[00:58:38.636]continues to grow at a very steep rate.
[00:58:45.714]Just a footnote to that,
[00:58:46.976]and then I do have a question.
[00:58:48.139]Doesn't water vapor in the form of clouds
[00:58:49.667]also increase albedo in somewhat offsetting fashion?
[00:58:55.105]My question is to you as a chemist,
[00:58:57.163]you mentioned that hydrofluorocar...
[00:58:59.672](tongue twister exasperation)
[00:59:01.231]HFC's, are to be banned.
[00:59:02.776]Is there a chemical replacement,
[00:59:04.657]because there are now people living in places
[00:59:06.761]where they will die without air conditioning?
[00:59:09.239]Yeah, that's a really good question,
[00:59:10.737]and it's interesting,
[00:59:12.896]I actually am not an expert at it,
[00:59:14.737]but I'll tell you what I know.
[00:59:16.049]It's a little surprising,
[00:59:17.703]because you know without,
[00:59:19.142]because the manufacturers of
[00:59:22.334]of air conditionings and refrigerators
[00:59:24.586]obviously need a refrigerant, right?
[00:59:26.897]And the new refrigerants which are not,
[00:59:28.694]that's the part I'm not an expert of,
[00:59:30.497]exactly what their chemical composition is,
[00:59:32.407]are gonna be more expensive,
[00:59:36.515]right for sure?
[00:59:38.256]But there has been buy-in from the chemical
[00:59:41.198]community, the manufacturing community
[00:59:44.052]to banned the hydrofluorocarbons.
[00:59:47.680]So there are replacements,
[00:59:50.538]they are unfortunately more expensive,
[00:59:52.437]and I, you know I hope and pray
[00:59:54.555]that they have been carefully vetted in terms
[00:59:58.501]of their impact on the environment,
[01:00:01.626]because, you know, no matter how we slice it,
[01:00:03.828]not all the, not all the, yeah not all the gas,
[01:00:10.977]you know, we have these refrigerants,
[01:00:13.293]we think they're contained
[01:00:14.555]and then you get rid of your refrigerator
[01:00:15.792]and it goes into a trash pile and
[01:00:17.508]or you have a leaky,
[01:00:19.537]what we used to call Freon in air conditioner
[01:00:22.201]and was refilled periodically,
[01:00:24.939]and so it's been tightening of all things.
[01:00:29.257]So yeah this is a challenge,
[01:00:30.931]and finding replacements that are both
[01:00:33.207]cost effective and not harmful for the environment
[01:00:37.222]are really gonna be a challenge.
[01:00:42.398]I'll toss one in,
[01:00:43.572]since I'm holding the mic.
[01:00:44.726]One of the things you didn't mention
[01:00:46.568]is there's a fairly controversial area
[01:00:48.756]of people trying to shift the
[01:00:50.890]equation on the other end of the spectrum
[01:00:52.579]in terms of duplicating the volcanic aerosols
[01:00:55.355]by a deliberate injection of
[01:00:57.833]articulates into the atmosphere,
[01:00:59.600]and that's this sort of rescue hypothesis
[01:01:01.508]of lowering temperature or buying time,
[01:01:03.539]the whole thing.
[01:01:04.850]Any comment on that?
[01:01:07.191]Okay, so I'll just repeat what you just said. (laughing)
[01:01:09.120]So yeah if you, if you take some silicone particles
[01:01:13.021]or something like that
[01:01:14.184]and you put them you know in a balloon
[01:01:15.711]and you send it up,
[01:01:17.479]we just, you know, what do I think?
[01:01:21.522]It's a first short-term thing,
[01:01:25.486]because they're not gonna stay there forever.
[01:01:27.200]We have no idea of the harmful impacts of them.
[01:01:32.858]We, you know I tried to mention
[01:01:37.282]that pollution in China,
[01:01:39.149]air pollution in China in someway has the same effect.
[01:01:41.983]The skies are dark,
[01:01:44.980]the amount of,
[01:01:47.963]the amount of particulates in the atmosphere
[01:01:50.109]are reflecting more and so
[01:01:52.721]when they clean their environment,
[01:01:53.913]will things accelerate even more
[01:01:55.796]because they'll be less reflection
[01:01:59.058]of sunlight coming about?
[01:02:01.200]So the answer is I don't think there's a magic bullet,
[01:02:04.709]and I don't think personally,
[01:02:08.724]and I was just re-reading a long special,
[01:02:13.338]special edition of the Economist on this,
[01:02:16.829]I really don't think that the current technologies
[01:02:19.540]are going to be able to save us.
[01:02:21.066]I think we are still looking for
[01:02:22.417]what are the future,
[01:02:24.002]I think we're still looking for solutions,
[01:02:28.644]the what am I talking about?
[01:02:29.657]I'm talking about all the fossil fuel burning
[01:02:31.085]is for generating energy right?
[01:02:33.546]We want energy to be a successful industrial society,
[01:02:36.143]and so the real question is
[01:02:38.258]how do we generate energy
[01:02:41.050]without impacting on our environment,
[01:02:43.072]and still have the,
[01:02:45.806]the world, you know the energy we need for growth?
[01:02:49.893]I think we need new technologies.
[01:02:51.816]I don't think it's just about batteries,
[01:02:53.467]I think it's, there are broad reaching
[01:02:59.155]and technology challenges that we have not addressed.
[01:03:03.358]That's my personal opinion, but you know.
[01:03:26.816]As a scientist,
[01:03:27.910]have you, you know, wondered why there are legitimate
[01:03:32.077]climate scientists who are skeptics?
[01:03:37.701]In fact, it's rather interesting,
[01:03:39.427]Dr. Wilheit and I were talking one day,
[01:03:42.488]and one of the, one of the published
[01:03:44.909]skeptics got his masters degree here at UNL.
[01:03:48.274]Take it back, take it back. (laughing)
[01:03:50.559]But what motivates people
[01:03:53.718]like that to, have you ever wondered about that?
[01:04:01.376]I, you know, either what motivates them
[01:04:03.239]or what other interests,
[01:04:04.460]what are their financial interest,
[01:04:05.700]do they have that we don't know about?
[01:04:09.002]I find it, I think so,
[01:04:14.340]I try to,
[01:04:15.361]I think the data is so compelling,
[01:04:17.293]and again like I tried to explain this Berkeley Earth Group
[01:04:23.665]was an example of skeptics and said okay
[01:04:25.619]let's go really look at the data,
[01:04:27.252]and ask you know if we analyze things really carefully.
[01:04:30.909]You know so at what,
[01:04:34.836]what you know,
[01:04:36.362]I guess the question is
[01:04:37.361]is it a policy thing that they,
[01:04:38.752]you know so there's a,
[01:04:40.284]I wanna separate the science from the policy,
[01:04:41.902]so what we should do about it.
[01:04:43.431]I've been trying to teach and talk tonight
[01:04:46.136]about the science.
[01:04:47.477]Policy is another whole thing.
[01:04:49.539]How much are we willing to pay,
[01:04:52.351]you know how much are we willing to sacrifice
[01:04:54.021]in order to turn this around?
[01:04:56.941]Are we willing to use less energy,
[01:04:59.648]are we willing to potentially have a recession
[01:05:03.078]because we've restricted the amount of energy
[01:05:05.223]we can use?
[01:05:07.220]Are we willing to
[01:05:10.021]allow other countries to use the amount of,
[01:05:13.955]of burnt fossil fuels at the rate that we have?
[01:05:17.728]I think, I think there are a lot of economic reasons
[01:05:22.785]why people don't want to address this issue,
[01:05:26.302]but that's separate from the science
[01:05:28.901]that is seems quite straightforward to my eye,
[01:05:32.972]and has been analyzed over and over and over again.
[01:05:55.068]Makes me wonder too.
[01:05:58.617]I'm a scientist, not a policy person, sorry. (laughing)
[01:06:02.851]Thanks for your excellent talk,
[01:06:06.691]My question is, goes to the location of accompanying you.
[01:06:11.771]You started your,
[01:06:13.699]the location of the company you started with the
[01:06:16.004]your talk and (inaudible)
[01:06:19.149]Based on your experience,
[01:06:21.097]how do you think new educators may jump into
[01:06:25.798]their sharing climate change,
[01:06:28.658]in a diversified environment of the students?
[01:06:34.366]That means those that are in the
[01:06:39.523]as well as other areas.
[01:06:42.437]What would you suggest for the teachers
[01:06:44.564]to raise climate change
[01:06:46.939]and share with other colleagues as well as they,
[01:06:49.099]or as well as the students?
[01:06:53.166]Yeah um, so what,
[01:06:56.579]so I think the question if I can just repeat back
[01:06:58.289]and make sure I'm getting it,
[01:06:59.724]is what can we as educators do?
[01:07:02.793]I didn't show this data as well
[01:07:06.057]but younger people seem to be more (tongue clicking)
[01:07:12.717]of the climate change phenomenon,
[01:07:14.511]so there seems to be a generational (clears throat)
[01:07:17.089]openness, you know more younger people
[01:07:19.778]are more open to these ideas.
[01:07:21.857]I think it's about teaching the science
[01:07:24.618]and giving the students confidence
[01:07:27.149]that the science has been rigorously
[01:07:29.750]examined and evaluated.
[01:07:33.077]I think that matters to them,
[01:07:35.477]and then to be open to listening to their ideas
[01:07:38.418]about policy and as I tried to emphasize tonight,
[01:07:40.765]to maybe illustrate the career opportunities
[01:07:43.788]for young people today to really work on this issue,
[01:07:48.103]on energy and on the environment
[01:07:50.667]and I hope that,
[01:07:52.778]just pointing out,
[01:07:54.745]having so, I don't,
[01:07:58.053]I work really hard on having them,
[01:08:01.557]appreciate that careful,
[01:08:04.761]very careful measurements are being made.
[01:08:07.280]I don't show models that are extending
[01:08:12.230]50 years out,
[01:08:14.016]with you know, 15 different slopes based
[01:08:16.661]on which model you you wanna pick.
[01:08:18.844]I mean they're all not good right?
[01:08:21.853]In terms of temperature rise,
[01:08:24.365]and amount of emissions.
[01:08:26.739]So I think,
[01:08:28.547]I work on building trust with,
[01:08:30.723]the general population builds trust in science
[01:08:33.989]and scientific data.
[01:08:36.068]That's my probably number one thing.
[01:08:42.167]Okay, what a great discussion.
[01:08:43.619]I think we fit the model of the visiting scholar
[01:08:45.745]program well or I hope we did,
[01:08:47.761]when you report back on this? (laughing)
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