Janet McMahon speaks about the transition to clean energy at the Arnold Arboretum in Boston.


The Climate Session, Palavar Strings, Arnold Arboretum, Boston, Massachusetts

May 2, 2015 


My name is Janet McMahon. I teach a course on Global Climate Change to high school sophomores.  In 1990, I went back to school, at what is now the Climate Change Institute at the University of Maine.  As part of my masters degree, I mapped the range limits of all the native tree species in Maine.  Two weeks ago, I had my students look at how the ranges of the state’s birds and trees are expected to shift as the climate changes.  We found that many animals and plants that are our neighbors now will have moved out of Maine by the end of the century, if not before.  Some examples? – balsam fir - the tree most of us bring into our homes at Christmastime and my favorite smell in the world, Maine’s state bird – the chickadee, and that iconic bird of the north woods - the common loon.

For those of us who live a life of relative ease in a northern latitude, information like this gnaws at us, but climate change doesn’t pose an existential threat.  If you live in the Marshall Islands, Bangladesh, New Orleans, or along any low coastline in a part of the world with a shaky infrastructure or a shaky government, the impacts of a changing climate are literally gnawing away at the ground beneath your feet, or the house you live in, or the reef where you fish, or the graves where your ancestors are buried.  You face the consequences of someone else’s actions every single day.

I struggle with how to talk about climate change to 15 and 16 year olds.  I want them to understand the science and what’s at stake, but mostly I want to show them that before us lies an opportunity to do something no other generation has done – and that is...to live on this planet in a sustainable way.  This century we will all witness and be part of a shift from fossil fuels to renewables.  This shift is being called The Great Transition.  Before I tell you about this transition and how it is unfolding, a few words on the science...

Despite what you may hear on the news or radio, the science is settled. 97% of the world’s scientists and governments (US Congress excepted) are not debating it. Scientists are long past the “oh shit” moment when they first realized the planet was in trouble.  That happened 50 years ago when the first scientists testified in Congress about the risks of increased CO2 in the atmosphere.  It’s not worth spending time trying to convince the deniers.  As a farmer from Nebraska put it, “It’s virtually impossible to reason someone out of a position they were never reasoned into.” 

The following is a tiny snapshot of what we know.  First...

1)     1 out of 4 CO2 molecules in the atmosphere has been put there by us.  By century’s end, if we stay on the current path, it will be 1 out of 2.  Translation:  the thicker the blanket of greenhouse gases, the warmer the planet.   Second:

2)     The 10 warmest years on record have all occurred since 1997, and last year - 2014 - was the warmest year yet.  This made the cover of the New York Times.  The “warmest year on record” has become normal for my students.  What was normal for me when I was their age was a winter like the one we just had.   Third: 

3)     There are now 7 billion of us. If everyone on Earth lived like an average American, we’d need 5 earths to support us all.   Fourth:

4)     By the time a child born today reaches old age¾the climate of Massachusetts will be comparable to Virginia’s.   And finally...

5)     To avoid entering a period of dangerous climate instability, scientists tell us that we need to cut fossil fuel emissions 80% by 2050.  80%!


How do you get your head around this?  As you politely listen to me, you’re probably thinking...

  • It’s impossible, there’s no point in trying...we can’t change the system...
  • It’s too expensive and will hurt the economy...
  • The environmentalists are dealing with it...
  • Technology will take care of it...
  • The market will take care of it...
  • It’s too distant and abstract to care about...
  • I’m already doing my part – I meditate, I recycle, I shop at the farmer’s market.
  • It hurts too much to think about what will be lost, so I’m just going to live my life...
  • It was your generation that caused the problem, so you fix it...
  • I’m not going to be around much longer.  My generation won’t really have to deal with it, so it’s up to you kids...
  • I’m just one person, how can I make a difference?...


I challenge you to look at the problem differently.

There is no doubt that this is a crisis, and getting to 80% is a huge task, but it is also an incredible opportunity.  We have all the tools we need right now to shift to a post-petroleum world.  Think about it as a choice – a choice between an economy based on fossil fuels - expensive, finite, dirty, unhealthy, and divisive and an economy based on renewables -  cheaper (in the long run), cleaner, fairer, and they’ll last as long as Earth itself.  

The Great Transition is a shift from an economy run largely on oil, gas and coal to an economy powered by the sun and wind. It’s already underway, it’s global, and it’s gaining momentum.  The Great Transition is being fueled by:

  • Economics – renewables are getting cheaper, extracting fossil fuels is getting more expensive
  • Technology – we’re figuring out how to run things on electrons rather than hydrocarbons and we’re making things more efficient; AND it’s being driven by
  • Public Pressure – There is growing public realization that the business as usual path isn’t sustainable, that the environmental and human health costs of fossil fuels are too high; and that the fossil fuel industry cares about the bottom line, NOT the next generation.

Here are just a few examples of what’s changing:

  • In the past decade, the cost of solar panels has dropped 80%, and the cost of wind turbines has fallen by half
  • We have all the solar and wind we need to replace fossil fuels – there’s more than 5000 times more solar E falling on the planet’s surface in a single day than our species uses in a year!
  • One in five Australian homes is powered by the sun.
  • Germany makes enough electricity from wind to power 6 New England’s.
  • In California, all new homes and commercial buildings will be built to net zero standards by 2030.
  • San Francisco, Munich and a hundred other cities are working to have 100% of their electricity come from renewables in a decade.
  • Walmart has installed solar arrays on 260 stores and plans to build another 400 arrays in the next 4 years.
  • Compact fluorescents have largely replaced incandescent light bulbs, and now we’re moving to LEDs, the end result?  a 90% increase in lighting efficiency
  • Saudi Arabia is building 41,000 MW worth of solar powered plants  = 41 nuclear reactors
  • In ten years, the fuel efficiency of new cars in the US will have doubled.
  • China invested $90 billion in renewables in 2014 - more than any other country - and is now the top market in the world for solar.  This is changing everything!


I could go on and on.  The ground is shifting, but we have to do everything we can to accelerate the transition.  Public action and pressure are critical.  What can we do?  It’s not rocket science – here are 4 actions you can take:

1)  Vote!  Vote as if your future depended on it, because it does. Vote for politicians who accept the science, want to level the playing field for solar, wind and energy efficiency, and are willing to put a price on carbon.  Vote at all levels – from local to national. Encourage your friends, children, parents to vote.

2)  Shift – If you own a house or plan to someday, consider solar – you can install panels on your own roof, or go in with families who have a better site.  Make your next car one that runs on electrons instead of gas, or don’t own one.  If you have a furnace, consider a heat pump.  Invest in an insulated basement.  All of these things will save you money in the long run. 

3) Conserve – Buy less, waste less. We can’t buy our way out of this.     And finally,

4) Divest - If you have money in the stock market, divest from fossil fuels and invest in renewables. Push your town or school or church to divest.  The divestment movement is picking up steam, and includes hundreds of individuals, foundations, churches, cities (including Cambridge), and universities (maybe Harvard will be next).


The question is no longer if the world will transition to cleaner energy, but how long it will take.  Will the Great Transition happen fast enough for the world to avoid catastrophic climate change?  No one can say with certainty.  Only time will tell. The train is leaving the station.  The more of us that get on, the faster and less disruptive the transition will be.  It’s time for every single one of us to get on board.