Your money or your life

They say the best things in life are free

well you can keep them for the birds and bees

     - the Beatles

Say a prayer 

for the salt of the earth

     -The Rolling Stones

Greetings

       I ran across a review by Kevin Anderson,  of Leonardo DiCaprio's film, Before the Flood.  Its worth reading.  Here.    He says that the movie does provide some good information, but that it leaves the viewer with the impression that there are easy technical solutions to climate change,  which do not require any changes to our life style.  He says:

"Certainly huge strides towards low carbon energy could be achieved now with existing energy supply and demand technologies. The research, development and deployment of promising new technologies, including Musk’s solar-battery future, could be accelerated. But Paris and carbon budgets frame an urgent problem far beyond the multi-decadal timeframe of deploying sufficient new energy technologies to displace fossil fuels. Deep and early mitigation through reduced fossil-fuel use by high emitters is key to both extending the window for this technology-transition and for leaving sufficient emission space for those in poverty to have near-term access to fossil fuel energy."

He also has some harsh words about the film's claim that a person can be "carbon neutral " by buying offsets,  saying, 

"I really doubt that the Pope, whose Encyclical makes more systems-level sense than the plethora of glossy reports dispensed by green-growth ‘think’ tanks (and who was interviewed for the film), would sanction the ongoing “buying of indulgences”. For that’s what it is. The emissions from first-class flights, grand hotel rooms and travelling film crews are changing the climate now – and will for the next ten thousand years. The deed’s been done – and no amount of conscience-salving finance can assuage the climate impact. Ok, the projects funded may have real and important value – but asking someone else to diet whilst we binge on high-carbon fun is simply fraudulent. "

      For all his good intentions, Leo doesn't want to give up his lifestyle.  None of us do.  Leo is worth $245 million.   He has the lifestyle of the rich and famous.   (But that's OK, I think he's a good actor.)  The rest of us just have the lifestyle of the rich.   After all, we are the top 10% of the world.     (Interesting fact:   The top 10%  is responsible for 90% of the CO2 .   That's us.    The folks whose  income is greater than $23 a day - $8400 per year.      ). 

      So naturally, we hope that technology and "green growth", can reduce CO2 while increasing GNP, so we can continue to enjoy that life.   Eric Lindberg, in his article,  Economic Growth A Primer , makes an effective argument that this is a comforting illusion, but that any growth of GDP is likely to continue make things worse .  He notes that 

"  As the global economy grows, species go extinct, rainforests are permanently lost, carbon emissions grow, and the world becomes hotter and hotter.  These trends are not reversing, nor is there any credible sense that they might.

Interestingly Bill Gates  (net worth  $85 B ), seems to agree with Lindberg , at least in part.    He says

"What’s amazing is how our intense energy usage is one and the same as modern civilization. That is, for all the great things that happened in terms of human lifestyle, life span, and growing food before 1800, civilization didn’t change dramatically until we started using coal in the U.K. in the 1800s 

He also doesn't think that renewables will provide the answer

  

"Today’s technologies are a good start, but not good enough. Some places don’t get enough regular sunlight or reliable wind to depend heavily on these sources. In any case, these and other clean-energy technologies are still too expensive to be rolled out widely in poor countries. They’re getting cheaper, but many developing countries aren’t waiting for these tools to become affordable. They’re building large numbers of coal plants and other fossil-fuel infrastructure now. That’s very unfortunate, but it’s understandable. We can’t expect them to wait decades for cleaner alternatives when their people need energy now.

So, Gates is looking for an "energy miracle".   

For an interesting exploration of the hype about fast renewable energy is taking over, and how much capacity has been built. see  How Renewable Energy Advocates are Hurting the Climate Cause 

Lindberg  is not looking for a miracle, he has a different solution, stop economic growth.

"True, economic growth does provide some short-term benefits and gains, and recessions are legitimately painful and destructive.  But economic growth is nevertheless the greatest threat to humanity today, and those most devoted to economic growth will, as its consistent performance begins to wane in the future, perhaps be the greatest political threat to ordinary people of the world."  

           Another certified rich guy, Warren Buffet, (net worth $76.9 billion) has famously said "Only when the tide goes out,do you discover who has been swimming naked."

           It seems that the tide is going out    NOAA reports:

"The annual growth rate of atmospheric carbon dioxide measured at NOAA’s Mauna Loa Observatory in Hawaii jumped by 3.05 parts per million during 2015, the largest year-to-year increase in 56 years of research.

           Even the super rich are feeling nervous , and hope to avoid the impacts by building  "lifeboats "-  small compounds in places like New Zealand,  complete with airfields and planes. ( one wonders how such compounds will do in a "long emergency"

        The impacts to "regular people" has begun.  Today, climate change accounts for 87 per cent of disasters worldwide. Some of the worst droughts in decades are continuing to unravel across southeastern Africa and Latin America. Cyclonic storms, floods, wildfires, and landslides are bearing on the world’s most vulnerable populations.

 Some suggest that we "brace for impact"  

"The challenge of adaptation directly exposes the climate crisis as a crisis of social justice. All disasters break open the wounds of unequal societies. Storms do not discriminate, but they do make landfall on landscapes riven by disparities of wealth, power and safety.

The labels of ‘natural disaster’ and ‘extreme weather’ can mislead us into thinking that the principal dangers we face stem from the atmosphere’s furies. But as geographer Jesse Ribot writes, ‘vulnerability does not fall from the sky.’ The wreckage of climate change is the product of collision: between environmental conditions and human realities."

         Some people can't afford swim suits. 

         For an interesting exploration of energy, climate and poverty, you may want to take a look at part of  Bill Gate's blog  Life In the Dark.     (I was quite taken by the picture of the Nigerian students, with no electricity at home, studying under street lights.)

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PS

              According to Kevin Anderson, if carbon emissions were to peak in 2020,   any hope of avoiding  a 2 degree rise would involve, " on the order of 10 percent reductions a year after 2020, leading to total decarbonization by 2035-45."

      With that in mind , lets look the "cap and trade" bill that has been introduced in the Oregon legislature.(  HB 2135 ).  It would  require carbon reductions on the following timetable .  By 2025 : 20% reduction , by 2035 : 45%, by 2050 : 75%. 

    

      What's the proper response to this?   Obviously it fails the "Anderson test".  Most glaring is that it never requires "decarbonization"  at all. Not by 2035-45 as Anderson suggest.  Not by 2050.   We never get to 100% reduction.  Ever.  Is it a "step in the right direction"?.    In some sense it is.  But, clearly, this bill is not shooting for 2 degrees.    But,  as they say, "politics is the art of the possible.:  What is possible, may not be what is necessary.

DEQ reports that  "the effects on statewide economic output would likely be small, coming in at “slightly positive or slightly negative,”      And perhaps that is the point.

       One possible way to look at all this, is by analogy .   When a ship is taking on water, you attempt to pump out the excess, , but there is a point at which the pumps are overwhelmed, see  e.g The Titanic..  At that point, pumping water will not improve things.   It's not a "step in the right direction".   It wouldn't really make it "less bad", because the ship is going down.  At that point it is time to put your energy elsewhere,  handing out life jackets , and   providing an orderly evacuation .    

     Similarly,  reduction in carbon emissions will be useful, but only up to a point.  That point is when the enough tipping points have been reached, and the climate change is self sustaining.  After that reductions will have no impact. 

 Have we crossed that line?  Hopefully not

But see here Massive Permafrost Thaw Documented in Canada, Portends Hige Carbon Release  

     In any event, one way or the other, we had probably better "brace for impact".

Teach your children well

But let us not talk falsely now

the hour is getting late

-Bob Dylan

You say you've got  real solution

we' d all like to see the plan

-The Beatles

Greetings

       I just saw a new presentation by Nate Hagens.   It's short version of a course he taught at the University of Minnesota called  Reality 101.    Got me thinking.   Suppose you were going to give some 18 year-olds an idea of what's in store for them.  What would you say?

          Strangely enough he never mentions Overshoot,  or Footprint.  But he does give an overview of the economy, energy, climate, extinctions  and the crowding out of wildlife.   He calls it The Great Acceleration, and displays a vary of graphic indicators noting that there are "hockey sticks everywhere".  He suggests we will be seeing things never seen before.  And  of course this is already happening.  Things  like a 50 degree temperature spike at the North Pole.  Things like climate change as a "disease muliplier", such as the Zika virus

As of today, authorities in Brazil, Colombia, Jamaica, El Salvador and Venezuela were urging women to avoid getting pregnant… It is unthinkable. Or rather, it is something out of a science fiction story, the absolute core of a dystopian future. — Bill McKibben in a recent statement on global warming and the now pandemic Zika virus. 

        As for the the economy, he believes we are near the end of growth, and the beginning of a deflationary depression.  He points out that in the US , growth has been over for the bottom 95% of us since 2000, when the median household income peaked.  He expects more poverty, noting that even now, most (63%) Americans don't have enough emergency saving to handle s $500 car repair bill, or $1000 medical emergency.   So, his advice is to prepare for LESS:   Less Energy, Stuff and Stimulation, and recommends focusing on more important things, like nature, friends and family.

        He expects the cost of energy to rise significantly,  He doesn't accept the mainstream view, which is that we can continue to live our high energy lifestyle based on renewable power.   Hagens says, of course build as much renewable power as you can, but recognize that wind and solar are not a panacea.  Even with the incredible growth , wind and solar are not replacing fossil fuels, but are merely increasing total energy consumption.  And despite their growth, they still only represent around 3% of total world energy use  And wind and solar only impact the electricity market, which is less than 20% of our energy use.  He says "no combination of  fossil fuels and renewable energy will maintain economic growth.".  Eventually,of course, we will be forced to move to a system of all or nearly all renewable power, but he estimates we'll have only 1/3 to 1/2  the power we have now.   Have to learn to "cook when the sun shines".  

       This view is echoed by Richard Heinberg, (see Can we have our climate and eat it too?, who notes that any attempt to transition to renewable power will result in much less available energy, especially if we attempt the transition called for to keep temperature growth near 2 degrees.

"It is unclear how much energy will be available to society at the end of the transition: there are many variables (including rates of investment and the capabilities of renewable energy technology without fossil fuels to back them up and to power their manufacture, at least in the early stages). Nevertheless, given all the challenges involved, it would be prudent to assume that people in wealthy industrialized countries will have less energy (even taking into account efficiencies in power generation and energy usage) than they would otherwise have, assuming a continuation of historic growth trends.

This conclusion is hard to avoid when considering the speed and scale of reduction in emissions actually required to avert climate catastrophe. As climate scientist Kevin Anderson points out in a recent Nature Geoscience paper:

According to the IPCC’s Synthesis Report, no more than 1,000 billion tonnes (1,000 Gt) of CO2 can be emitted between 2011 and 2100 for a 66% chance (or better) of remaining below 2 °C of warming (over preindustrial times)… However, between 2011 and 2014 CO2 emissions from energy production alone amounted to about 140 Gt of CO2… [Subtracting realistic emissions budgets for deforestation and cement production,] …the remaining budget for energy-only emissions over the period 2015–2100, for a ‘likely’ chance of staying below 2 °C, is about 650 Gt of CO2.

That 650 gigatons of carbon amounts to less than 19 years of continued business-as-usual emissions from global fossil energy use. The notion that the world could make a complete transition to alternative energy sources, using only that six-year fossil energy budget, and without significant reduction in overall energy use, might be characterized as optimism on a scale that stretches credulity."

   And even if we could,  what would be the environmental effect?

Heinberg says:

"According to the Global Footprint Network’s Living Planet Report 2014, the amount of productive land and sea available to each person on Earth in order to live in a way that’s ecologically sustainable is 1.7 global hectares. The current per capita ecological footprint in the United States is 6.8 global hectares. Asking whether renewable energy could enable Americans to maintain their current lifestyle is therefore equivalent to asking whether renewable energy can keep us living unsustainably. The clear answer is: only temporarily, if at all . . . so why attempt the impossible? We should aim for a sustainable level of energy and material consumption, which on average is significantly lower than at present.

Efforts to pre-adapt to shrinking energy supplies have understandably gotten a lot less attention from activists than campaigns to leave fossil fuels in the ground, or to promote renewable energy projects. But if we don’t give equal thought to this bundle of problems, we will eventually be caught short and there will be significant economic and political fallout."

       Is this the "reality" which most young people are expecting?  Probably not. Because,  most people they tune out such information.  Hagens also addresses this "cognitive dissonance",  which he defines as "believing something that is totally contrary to reality".  He explains that it is a well known  in psychology as way of reducing stress.     

       He devotes  some time to similar "biases" which have been useful through out our evolutionary history, but which are now making it difficult to see objectively.     So we we see the world through tinted glasses.  In that sense we are all "delusional".     That we are easily influenced by authority, by charismatic people, by peer pressure,and  by our own bias towards optimism  (all the children are above average).  We are driven to "keep up with the Joneses"  These biases are built in "features",  that by virtue of our new situation, they have become "bugs".

      So, if you've got an 18 year old around the house, you may want to watch this video together, and talk it over.  Then, take a walk in the woods, you'll both feel better

Elon Musk and the Holy Grail

The ornaments look pretty
But they are pulling down the branches of the tree

    - Cake

Come in here, dear boy, have a cigar.
You're gonna go far, you're gonna fly high,
You're never gonna die, you're gonna make it if you try;
    - Pink Floyd

Greetings


     Elon Musk is a hero for our time.  A certified billionaire, he invented a new way for people to buy stuff, by just pressing a button!    His ideas are extremely revolutionary.  And visionary, too.   He is now is in the process of revolutionizing transportation,.  And recently he announced a new product which will revolutionize the way power is stored.

      The Holy Grail?  Well, that is our dream that we will be able to continue our high energy lifestyle.  Or as Doomer Dan would say -  to continue to be able to "drive around and buy sh*t"   see e.g. The Amazing New Thing    Without  all those nasty CO2 emissions.

      So with Musk at the helm,  can we relax now?

      Will his cool products help us get the holy grail?  The good life , while avoiding "dangerous" warming,  possibly  triggering unstoppable feedbacks?    (What would it take to get there?  For developed nations - perhaps cut about 50% by 2020  (2013 study) .
   
        Let's start with the car.  Its pretty darn cool.  It can go from 0 to 60 in 4.2 seconds.  Not mention 130 MPH!      

        The value of electric vehicles in addressing carbon emissions is still a matter for debate.  First of all, most agree that the emissions from an EV will vary widely, depending on the electricity production mix in the state where the vehicle is charged.  .  While some states have a low carbon mix, the US average is so carbon heavy that EV's , are about as helpful as a car that gets 40 MPG

       In addition, the manufacture of an EV uses more fossil fuels than a gas powered car.  This can create a large "carbon debt"  that may or may not be paid off, even if the car is refueled using renewable power.  For instance this report from Climate Central says.

"Another critical factor is the carbon emissions generated when a car is manufactured. Emissions from producing the battery and other electrical components create a 10,000 to 40,000-pound carbon debt for electric cars that can only be overcome after tens, or even hundreds of thousands of miles of driving and recharging from clean energy sources."

       And the "power wall" ?    At first blush it sounds like the device that has been missing from the renewable energy  story.   Solar and wind may be low carbon, but they are also intermittent.   As long as we want 24/7 power, we will need storage.  Now, it's really not an issue, because the grid itself, with all of the existing power plants, can be used a battery, providing power when needed.   At some point, if we are ever able to move to a system that it more dominated by renewables, it will be useful.

        Right now, though, the "Power Wall" is something like the Tesla.  One might say its  an expensive toy for rich people who want to give the impression they are doing something useful for the ecosystem . It doesn't do much for the biosphere, but it looks really good.  As noted by Bloomberg

"To provide the same 16 kilowatts of continuous power as this $3,700 Generac generator from Home Depot, a homeowner would need eight stacked Tesla batteries at a cost of $45,000 for a nine-year lease. "It's a luxury good—really cool to have—but I don't see an economic argument," said Brian Warshay, an energy-smart-technologies analyst with Bloomberg New Energy Finance."  

                  But let's set that aside for now.   Perhaps one could argue that it was a step towards a solution.   Why not let the rich subsidize the development of a useful part of a solution to our climate conundrum ?   Once again the holy grail .   Can we have our cake and eat it too?  Which is to say - if we move to a low carbon society - how much energy will we get?   If it is anything like what we use now, we will need a lot of batteries!

             I ran across an interesting study from the journal  Energy Policy, found here which helps to put this issue into perspective.   The authors took note of a the idea, promoted in several studies that we could create a completely renewable energy system by 2050.  ( I recognize that this is somewhat less ambitious than the goal stated above of cutting our emissions in half by 2020, but its in the ball park).   

         The authors asked an interesting question about that "all renewable" energy system.   How would get there?   And how we we keep it there I.e. handle the replacement of the units as they fell apart.   For simplicity they focused on the wind component, only.  .  They construct a scenario, under which, the installation of turbine grows , nearly exponentially, each year up to 2050.   (Needless to say, a growth rate this steep has not been seen in history, but that's OK )    From 2050 on the the worn out  units are replaced ,  requiring  construction of 12 Twatts each year.  To get an idea of the scale of  the material requirements for the maintenance period , assuming some of the material is recycled ,they compared it to material uses today .  The requirements are rather stunning, considering that under this scenario, wind provides only 15% of the power!:

"Under these assumptions, only sustaining the 24 TW of wind energy, assumed to provide 15 % of global energy demand by Kleijn and Van der Voet (2010), would need the equivalent of 11 % of total global steel production and 14 % of global copper production (based on 2012 rates of production). This means that reaching and sustaining this installed wind capacity would require quantities of steel that is similar to the current automotive industry, that used 12 % of the steel produced in 2011, while the entire sector of electrical equipment used only around 3 % (World Steel Association, 2012). The amount of copper needed for the turbines is comparable to what is used for making electric motors, of around 12 % of the global copper production, while the electric energy transmission sector use about 26 % (Achzet et al., 2011). " 

        Where would such an enormous amount of material; come from?   Looking forward, it seems unlikely that we will be able to devote this amount of materials to the construction of wind turbines, and in addition also construct large amounts of solar devices, as well as the batteries to store all the energy.    More likely, when confronted with that expense, we will continue to operate as we have, until some resource limit forces us to do otherwise.

       Many of us wish for a bright, shiny techno future.  We also dream about a world that is not being upset by droughts, fires, and rising seas.  It does not seem likely to me that we will have both of these futures.    More likely , to me, is the vision offered by Richard Heinberg.  (see e.g. useful short videos here ) A future of less energy, less consumer goods, and one which will, still nevertheless be subject to many of the climate change induced problems       This future will be a lot more difficult , if we don't prepare, because we are too dazzled by the dream of a technological "deus ex machina".  

Leading a horse to water

It's getting better all the time

Can't get no worse

     - Beatles

Don't turn on the lights

cause I don't wanna see

     _Randy Newman  (Momma told me not to come)

Greetings

      We've all seen the headlines about how cheap wind and solar are, and how they are growing by leaps and bounds.   Surely they will overtake fossil fuels soon!   Bloomberg Reports "Fossil Fuels Just Lost the Race Against Renewables"    Michael Klare reports that its a "Renewable Revolution" 

   It all sounds pretty exciting.  With all this cheap renewable energy, businesses and utilities are bound to switch.   Right?    

       Of, course we would all welcome a renewable revolution - one where renewables  were a substitute for fossil fuels, one that would result in a reduction of CO2.   But its not clear this this " revolution"  is quite living up to those hopes.    Its true that renewables are getting cheaper, and they are getting installed at breakneck speed.    And that';s been true for the last ten to fifteen years.  But the results are less stunning.   In 2000, renewables amounted to 13% of total world energy use.    And that is about what it is today.(2013 data)       So  the tremendous growth in solar and wind has not displaced the burning of fossil fuels, . but merely supplemented them.   This is of course confirmed by the growth in CO2 emmissions  

      One reason is that renewables are mainly focus in electricity generation, which is only 40% of the energy use.   Transportation and industrial use has had little impact from renewables.   But even looking electrical generation ,   fossil fuel generated power continues to grow ( US).

     OK, so its still early in the game.,  Renewables are growing at exponential rates.  At some point they will  break out and  take over  from fossil fuels?   Perhaps,  but it may take a lot longer than than we'd like .  Smil suggests that, if history is any guide, it will take 50-60 years.  Here's another interesting piece from Nature suggesting some " laws of energy transitions" , which describes the likely trajectory. They suggest that new energy systems initially have an exponential growth rate, but that it soon turns into a straight line.   The authors also suggest the underlying cause.  Basically, it's the problem of " stranded assets".  Large energy users may be willing to buy renewables once the old devices break down.  But as long as the old coal fired furnace still works, they are not willing to swap it out.

     This makes some sense.   Imagine you have an ICE car.  Now an electric car comes on the market.   Even if the the electric will save money over the long run, you may not buy it.  Why shell out all that money, when the ICE runs fine?   Now, imagine your ICE is an energy system that costs hundreds of thousands, and is designed to last 25 years.   A tax incentive may help you decide which system to buy, once you are in the market.  But its less likely to move you into the market in the first place.

      All this suggests that a "supply side" approach has its limits, and won't get us where we need to go.  We need a reduced  demand for fossil fuels. not merely an incre4ased supply of renewables.          

   Below  (and here ), Brad Plummer explains further. 

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Clean energy is growing fast — but it's not yet winning the race against fossil fuels

For decades, fossil fuels have provided the vast, vast majority of the world's energy. But in recent years, cleaner sources like wind and solar have been growing at an astonishingly rapid clip.

So a lot of people are keenly interested in when we might hit a tipping point. When will clean energy start growing faster than fossil fuels? This week, Bloomberg declared we've already hit that point: "Fossil Fuels Just Lost the Race Against Renewables." That's stirred a lot of excitement.

Unfortunately, that headline isn't quite right. Clean energy isn't winning the race against fossil fuels. Not yet. And it's worth exploring in more detail why this is wrong — to better understand just how massive a task it will be to clean up the world's energy supply and avoid significant global warming.

This chart, showing clean energy winning, omits a few things...

Bloomberg's key piece of evidence is a chart from Bloomberg New Energy Finance showing that countries around the world added more electric generating capacity from hydropower, nuclear, solar, wind, biomass, and geothermal in 2013 than they did from oil, gas, and coal:

(Bloomberg New Energy Finance)

That is a neat milestone. But it doesn't prove that clean energy is growing faster than dirty energy. There are a two big things this chart omits:

1) Electricity is not the same as energy. The first thing to note is that the chart above only shows electricity capacity additions. Remember, "electricity" is not the same thing as "energy." We use electricity to power our homes and appliances. But most of the world's cars and planes don't run on electricity; they run on oil. A lot of buildings don't use electricity for heat; they burn gas. Those non-electricity energy sources aren't counted above.

Yet if we're worried about global warming, we have to consider that bigger picture. Electricity and heat were only responsible for about 42 percent of global CO2 emissions from fuel combustion in 2012. For clean energy to truly win the race, it will have to make inroads in other sectors as well, particularly transportation.

2) 1 GW of solar is not equal to 1 GW of coal. The second criticism of the chart above is that it only shows electricity capacity additions. "Capacity" is defined as the maximum output a power plant can produce under specific conditions. It is not same as how much electricity a power plant will actually generate in its lifetime.

Here's a way to illustrate the difference: coal plants can burn coal pretty much around the clock. So, over the long run, a coal plant will typically produce around 50 to 80 percent of its maximum output. Solar photovoltaic panels, by contrast, usually only work when the sun is shining. In the long run, they might produce just 20 percent of their maximum output. These percentages are known as "capacity factors."

This is important to keep in mind. Imagine that the world installed 2 gigawatts' worth of solar panels and a 1-gigawatt coal plant. If you only looked at a chart of capacity additions, you'd assume solar is absolutely crushing coal. But that's not necessarily true! When you take capacity factors into account, the coal plant is likely producing more total electricity.

For now, fossil fuels are still keeping pace with renewables

So let's look at a better chart that shows the world's energy consumption from different sources. This way we're looking at all primary energy — not just electricity but also cars and airplanes and heating and so on. We're also not being misled by looking solely at capacity; we're looking at actual use.

As it happens, BP offers this data in its Statistical Review of World Energy 2014. And the chart below looks more daunting for clean energy:

All told, fossil fuels made up 87 percent of the world's primary energy consumption in 2013. By contrast, low-carbon sources — including nuclear, hydropower, wind, solar, and biomass — made up just 13 percent.

That ratio hasn't changed since 1999, as the University of Colorado's Roger Pielke Jr. points out. In other words, the world's energy supply hasn't gotten any cleaner for 14 years.

Yes, clean energy sources have been rising over that time. That little yellow sliver showing renewable energy is growing at rapid clip (that includes solar and wind, but it also includes biomass energy and biofuels/ethanol for vehicles, both of which often come in for criticism). Hydropower is also expanding. Nuclear power, by contrast, is stagnating.

But coal, natural gas, and oil have more than kept pace with the growth of clean energy. An illustrative example: In 2013, non-hydro renewable energy consumption grew by 38.5 million TOE (tons of oil equivalent). But coal consumption grew by 103 million TOE — more than twice as much. If this is a race, fossil fuels are holding their own.

There's reason to be optimistic about clean energy — but the challenge is daunting

Solar panels in a row at sunrise. (Photo by Frank Bienewald/LightRocket via Getty Images)

Now, this isn't meant to be a pessimistic post about renewables. That Bloomberg chart does offer some genuinely good news about clean electricity — namely, that the world is building more and more power plants fueled by solar, wind, and hydro, while the pace of fossil-fuel plant additions is slowing down.

What's more, there are lots of encouraging clean-energy trends out there. The cost of wind and solar has been dropping dramatically all over the world. The price of batteries for electric cars has been plummeting much faster than expected (which is crucial, because building cars that run on clean electricity instead of gasoline will be an important part of greening the energy supply). Meanwhile, China has been cracking down on dirty coal plants in a quest to mop up air pollution.

Given these trends, it's quite likely that, at some point soon, clean energy will grow faster than fossil fuels globally. Maybe we're already approaching the inflection point. Maybe we'll hit it in 2020. It's hard to predict exactly. But when that happens, the fraction of energy we get from low-carbon sources will start expanding. The fraction of energy from fossil fuels will start shrinking.

Still, if the world wants to avoid drastic global warming, then it's not enough to have some progress in clean energy here or there. There will need to be a truly seismic shift — the proportion of energy we get from carbon-free sources would have to rise from 13 percent to something like 90 percent this century, maybe more.

We're not yet close to that pace. Here's a glimpse at how dramatically our energy system would have to change to get there.

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(Thanks to Robert Wilson for first pointing out/critiquing the Bloomberg story, which is being circulated far and wide this week.)