Tag Archives: climate change

The What and Why of Carbon Budgets

If you’ve been paying much attention to the climate policy discussion over the last few years, you’ve probably heard mention of carbon budgets, or greenhouse gas (GHG) emissions budgets more generally. Put simply, for any given temperature target there’s a corresponding total cumulative amount of greenhouse gasses that can be released, while still having a decent chance of meeting the target. For example, the IPCC estimates that if we want a 2/3 chance of keeping warming to less than 2°C, then we can release no more than 1000Gt of CO2 between 2011 and the end of the 21st century.

The IPCC estimates that if we want a 2/3 chance of limiting warming to less than 2°C, then we can release no more than 1000Gt of CO2 equivalent between 2011 and the end of the 21st century.

The reason the IPCC and many other scientist types use carbon budgets instead of emissions rates to describe our situation is that the atmosphere’s long-term response to GHGs is almost entirely determined by our total cumulative emissions. In fact, as the figure below from the IPCC AR5 Summary for Policymakers shows, our current understanding suggests a close to linear relationship between CO2 released, and ultimate warming… barring any wild feedbacks (which become more likely and frightening at high levels of atmospheric CO2) like climate change induced fires vaporizing our boreal and tropical forests.

Carbon Budget vs. Cumulative Warming
Figure SPM.5(b), from the IPCC AR5 Summary for Policymakers.

What matters from the climate’s point of view isn’t when we release the GHGs or how quickly we release them, it’s the total amount we release — at least if we’re talking about normal human planning timescales of less than a couple of centuries. This is because the rate at which we’re putting these gasses into the atmosphere is much, much faster than they can be removed by natural processes — CO2 stays in the atmosphere for a long time, more than a century on average.    We’re throwing it up much faster than nature can draw it down.  This is why the concentration of atmospheric CO2 has been marching ever upward for the last couple of hundred years, finally surpassing 400ppm this year.

So regardless of whether we use the entire 1000Gt budget in 20 years or 200, the ultimate results in terms of warming will be similar — they’ll just take less or more time to manifest themselves.

Unfortunately, most actual climate policy doesn’t reflect this reality.  Instead, we tend to make long term aspirational commitments to large emissions reductions, with much less specificity about what happens in the short to medium term.  (E.g. Boulder, CO: 80% by 2030, Fort Collins, CO: 80% by 2030, the European Union: 40% by 2030).  When we acknowledge that it’s the total cumulative emissions over the next couple of centuries that determines our ultimate climate outcome, what we do in the short to medium term — a period of very, very high emissions — becomes critical.  These are big years, and they’re racing by.

Is 1000Gt a Lot, or a Little?

Few normal people have a good sense of the scale of our energy systems. One thousand gigatons. A thousand billion tons. A trillion tons. Those are all the same amount. They all sound big. But our civilization is also big, and comparing one gigantic number to another doesn’t give many people who aren’t scientists a good feel for what the heck is going on.

Many people were first introduced to the idea of carbon budgets through Bill McKibben’s popular article in Rolling Stone: Global Warming’s Terrifying New Math. McKibben looked at carbon budgets in the context of the fossil fuel producers. He pointed out that the world’s fossil fuel companies currently own and control several times more carbon than is required to destabilize the climate. This means that success on climate necessarily also means financial failure for much of the fossil fuel industry, as the value of their businesses is largely vested in the control of carbon intensive resources.

If you’re familiar with McKibben’s Rolling Stone piece, you may have noticed that the current IPCC budget of 1000Gt is substantially larger than the 565Gt one McKibben cites. In part, that’s because these two budgets have different probabilities of success. 565Gt in 2012 gave an 80% chance of keeping warming to less than 2°C, while the 2014 IPCC budget of 1000Gt would be expected to yield less than 2°C warming only 66% of the time. The IPCC doesn’t even report a budget for an 80% chance. The longer we have delayed action on climate, the more flexible we have become with our notion of success.

Unfortunately this particular brand of flexibility, in addition to being a bit dark, doesn’t even buy us very much time. If we continue the 2% annual rate of emissions growth the world has seen over the last couple of decades, the difference between a budget with a 66% chance of success and a 50% chance of success is only ~3 years worth of emissions. Between 50% and 33% it’s only about another 2 years. This is well-illustrated by some graphics from Shrink That Footprint (though they use gigatons of carbon or GtC, instead of CO2 as their unit of choice, so the budget numbers are different, but the time frames and probabilities are the same):

Carbon-budget1

Like McKibben’s article, this projection is from about 3 years ago. In those 3 years, humanity released about 100Gt of CO2. So, using the same assumptions that went into the 565Gt budget, we would now have only about 465Gt left — enough to take us out to roughly 2030 at the current burn rate.

There are various other tweaks that can be made with the budgets in addition to the desired probability of success, outlined here by the Carbon Tracker Initiative.  These details are important, but they don’t change the big picture: continuing the last few decades trend in emissions growth will fully commit us to more than 2°C of warming by the 2030s. 2030 might sound like The Future, but it’s not so far away.  It’s about as far in the future as 9/11 is in the past.

It’s encouraging to hear that global CO2 emissions remained the same in 2014 as they were in 2013, despite the fact that the global economy kept growing, but even if that does end up being due to some kind of structural decoupling between emissions, energy, and our economy (rather than, say, China having a bad economic year), keeping emissions constant as we go forward is still far from a path to success. Holding emissions constant only stretches our fixed 1000Gt budget into the 2040s, rather than the 2030s.

If we’d started reducing global emissions at 3.5% per year in 2011… we would have had a 50/50 chance of staying below 2°C by the end of the 21st century. If we wait until 2020 to peak global emissions, then the same 50/50 chance of success requires a 6% annual rate of decline.  That’s something we’ve not yet seen in any developed economy, short of a major economic dislocation, like the collapse of the Soviet Union.  And unlike that collapse, which was a fairly transient event, we will need these reductions to continue year after year for decades.

Growth-rates2

The Years of Living Dangerously

We live in a special time for the 2°C target.  We are in a transition period, that started in about 2010 and barring drastic change, will end around 2030.  In 2010, the 2°C target was clearly physically possible, but the continuation of our current behavior and recent trends will render it physically unattainable within 15 years.  Barring drastic change, over the course of these 20 or so years, our probability of success will steadily decline, and the speed of change required to succeed will steadily increase.

I’m not saying “We have until 2030 to fix the problem.”  What I’m saying is closer to “We need to be done fixing the problem by 2030.”  The choice of the 2°C goal is political, but the physics of attaining it is not.

My next post looks at carbon budgets at a much smaller scale — the city or the individual — since global numbers are too big and overwhelming for most of us to grasp in a personal, visceral way.  How much carbon do you get to release over your lifetime if we’re to stay with in the 1000Gt budget?  How much do you release today?  What does it go toward?  Flying? Driving? Electricity? Food?  How much do these things vary across different cities?

Featured image courtesy of user quakquak via Flickr, used under a Creative Commons Attribution License.

Climate Action Across America

“Climate Action Across America” is a week-long, nation-wide, grass-roots effort next week (April 21 to April 25) to ask Congress to join the fight against climate change.  Our Congressional representatives are scheduled for a “constituent work week” that week, following Easter, so this is a great opportunity to call, write, or meet with our Congressional delegation or their staff about the need to support climate action.

On Saturday, April 26, the week will conclude with a rally in Washington, DC, to urge President Obama and Congress to reject the Keystone XL “export” pipeline, and to protect America’s people, land, water, and climate from the tar sands pipeline.  For more details, visit www.350.org.

In Colorado, here are in-state phone numbers to call to ask for a meeting or to leave a message supporting federal action to reduce greenhouse gases and prepare for future climate disasters:

Wherever you live in Colorado, please call all of your Congressional representatives.  Regardless of their prior views on climate change, they need to hear from growing numbers of citizens who are concerned about climate change and willing to call their offices.

On Twitter, you can participate in “Climate Action Across America” by using the hash tags #ActOnClimate, #ClimateActionAcrossAmerica, and #CongressJoinTheClimateFight.

Sustainability by the Numb3rs: Understanding Order of Magnitude Calculations

Understanding Order of Magnitude
Calculations

March, 27th, 5:30 pm – 7:00 pm
Fuse @ The Riverside
1724 Broadway St, Boulder, CO 80302

Register Here

This is the first in a series of classes hosted by Clean Energy Action and Boulder Free School.  Find out more on the main course index page.

Class Outline:

Order of magnitude calculations or estimates are a tool commonly used in the natural sciences to understand the general shape and scale of an interesting system.  They use approximate numbers and simple arithmetic to make educated, quantitative guesses or estimations.  The rest of this course will rely on order of magnitude calculations extensively, so it’s important that we make sure everyone has the basic tools required to do them.  They’re also known as “Fermi problems” or “Fermi estimates” after the Italian physicist Enrico Fermi, who was famous for making very fast, roughly correct, estimates of all kinds of crazy things.  This little video from TED-Ed gives a quick intro:

For Example:

If you’re going on a backpacking trip for a week, and a friend tells you their backpack weighs either 5 lbs or 500 lbs, you know intuitively that something is very wrong — you have a grasp of the scale of a backpack — 50lbs is about right. Maybe 35lbs if you’re going ultra-light, maybe 70lbs if you’re a mule, but definitely not 5 or 500.

If you know how to do order of magnitude calculations, you can quickly develop a similar intuition about lots of other kinds of physical systems, including those that are much bigger or smaller than your everyday experience.

Why is this important or useful?

This is important in the context of sustainability, because many of the systems we interact with and affect today are global, and far larger than it’s easy for us to grasp based on our normal daily experience.  Instead we have to build this intuition up for ourselves by playing around with the numbers.  It’s also important because there are a lot of “solutions” out there which might sound good as stories, but when you look at how big an impact they can actually make numerically, they turn out to just be marketing hogwash or outright disinformation.  The media doesn’t do a good job of differentiation between real solutions and hogwash, but with just a little bit of arithmetic and access to the Wikipedia and other online resources, you can get a good idea for yourself.

In this class:

We will explore…

  • The difference between accuracy and precision, and why it’s often desirable to make estimates which are imprecise, but relatively accurate.
  • Scientific notation — what it is, how to use it, and why it’s useful.
  • Units — the importance of keeping track of them, and what they mean, more generally.

Then we’ll do some easy warm-up calculations to try and wrap our heads around the scale of various pieces of our energy system.

Homework:
Teacher Bio

Once upon a time at NASA, Zane got a PhD studying the climate history of Mars, and the geology of the icy moons of Jupiter and Saturn.  Now he’s Clean Energy Action’s director of Research and Policy, working on climate and energy policy, and trying desperately to get everyone to turn off the terraforming machines before it is too late.  Zane also works on sustainable transportation, land-use, and community housing in Boulder.  He lives in a co-op with 11 other people, and his two bicycles and zero cars.

Colorado Wildfire Climate Change Fail

The past couple of years have been rough on Colorado, in terms of climate change related disasters.  First a couple of record setting wildfire years, and then floods of “biblical” proportions.  At a gut level we know we have to respond, but our public discourse is having trouble addressing the root cause directly.  Instead we’re dancing around the issue, and failing to either adapt adequately to our new reality or to mitigate further climate change.

Adaptation?

Bills related to both the wildfires and last fall’s floods have been wending their way through our state legislature, and last week legislators and the governor held a press conference to highlight some of them, and a lot of the resulting commentary seemed to focus on the safety and well being of the firefighters and other emergency services workers that risk their lives on our behalf.  Largely absent from the discussion were the strong measures that the Governor’s wildfire task force put forward in the fall. They included:

  • Creating a wildfire risk map, and rating all properties on a scale of 1 to 10,  requiring that risk designation to be disclosed before any property sale, and making it available to insurance companies for use in setting their rates.
  • Charging those living in the “wildland urban interface” a fee based on their risk exposure, that would be used to defer some of the additional public costs incurred in protecting their private property.
  • Creating fire-resistant building codes for high risk areas, affecting both the materials used in construction, and requirements for defensible space around buildings.

Make no mistake: these are climate change adaptation measures, and Colorado has rejected them.

Firefighters in Waldo Canyon

As the Denver Post reported in September: developers didn’t like the idea of increased construction costs; the real-estate industry didn’t like the idea of making a lucrative market much less attractive; homeowners in high risk areas certainly didn’t like the idea of paying for the risks they’ve taken on, or making those risks transparent to potential buyers of their property.

Would the discussion be any different if people understood that the wildfire frequency and intensity is likely to just keep increasing as climate change marches on?  This is about as close as the article from September gets to mentioning climate change:

Colorado terrain ravaged by wildfire has quadrupled from 200,000 acres in the 1990s to nearly 900,000 acres in the 2000s.  “Scientists tell us this pattern isn’t going to change,” Hickenlooper said.

Why is the “pattern” there in the first place?  What kind of scientists was the Governor was talking to?  None of the press articles linked to from this post mention climate change even once, despite universally pointing out the trend.  For example: As Colorado wildfires continue to worsen, only moderate laws proposed.  And why are they worsening?  No comment.  Even the wildfire task force’s report mentions climate change only once in 80 pages.

Waldo Canyon Fire Aftermath

The only big risk factor we’ve talked about directly is where we choose to build our homes.  This is an important discussion too.  The overall wildfire risk — at least to human lives and property — is something like:

(human risk) = (area burned) x (pop. density in high risk areas)

Climate change will in large part determine how much of our state burns each year, but we have a choice about how many people and how much property to put in areas subject to burning.  Reducing our exposure to the increasing wildfire risk is an adaptation to climate change — an alteration of our behavior, in light of the expected risks going forward.  For the moment at least, we seem unwilling to listen to the warnings.

But hey, at least the state had a conversation, and decided not to do anything.

Cause and Effect

So what are the causes?  According to the US Forest Service, the enormous bark beetle kill is due in part to warmer winters, resulting from climate change.  These forests filled with dead trees are warm and dry for longer each year, lengthening the western US fire season by about 2 months.  So it’s perhaps unsurprising that the number of large wild fires per year has already increased from 140 in the 1980s, to 250 in the first decade of the 2000s.  This infographic from the Union of Concerned Scientists is a good cartoon summary:

Western Wildfires and Climate Change

(see this paper for the references behind the infographic)

The third panel is probably the scariest for Colorado.  The dark red swath covering most of the western half of the state means that we expect more than six times as much land to burn each year in the near future, with just 1°C (1.8°F) of additional warming — and as Kevin Anderson and many others have pointed out, it is virtually certain that we will see another 1°C of warming… if not 3°C, or even more.

So our elected representatives are right to be concerned about increased risk from wildfires, and about the safety of the firefighters who try to protect us from those fires.  But we’re still missing the point:  We control our exposure to risk locally, and we control the magnitude of that risk globally.

Mitigation?

Policies aimed at avoiding or reducing climate change (like putting a price on carbon) are mitigation efforts.   We’re not talking about them much, even in the context of an obviously climate mediated risk like wildfires.  This is bad.  If we can’t have a conversation about what’s increasing the wildfire risks, how can we hope to respond appropriately?  Is our refusal to respond to change related to our refusal to accept the cause of the change?  Or is it more a kind of landscape amnesia — an inability to even see the change?  Are we going to forget what normal fire seasons looked like, in the same way that we’ve started to forget what a normal winter feels like:

Cold

Double Climate #Fail

Right now we’re managing to fail doubly with respect to climate change.  We are both unwilling to adapt to the foreseeable risks, and unwilling to even mention that these risks are linked to our greenhouse gas emissions, let alone talk about what we might do to mitigate those emissions and the risks that they create.

If we really care about our firefighters, if we really are intent on avoiding ever more costly and tragic conflagrations in our state, we need to both adapt and mitigate.  We need to start building for a warmer world now, and we need to stop warming the world as quickly as possible.

If you agree, look up the contact information for your Colorado state legislators and let them know.

GWSSS Denver: Utility Death Spiral

Zane Selvans, Research Director, Clean Energy Action

January 27th, 2014, 6:30 pm – 9 pm
Harry’s @ Vine Street Pub
1700 Vine Street, Denver, CO 80206

CLICK HERE TO REGISTER

Join CEA at Vine Street Pub in Denver for drinks, discussion and some live music from 6:30 to 9pm, Monday January 27th.

We’ll reintroduce the Utility Death Spiral, and talk about why century-old centralized monopoly utilities are failing to meet the challenge of climate change.  We’ll also explore how utilities need to evolve if they’re going to successfully integrate efficiency, distributed generation, and demand side resources dispatched over a much smarter grid. Utilities are terrified of cheap distributed solar power, because it is poised to disrupt their century old monopoly business model.  Come find out why the old way of generating electricity isn’t going to serve us well in the 21st century, and what might lie ahead.

And then, we’ll just hang out and continue the discussion face to face, with some local live music to set the mood.

A rough program:

6:30 – 7:00pm — Set-up and Mingling.  Get a drink.

7:00 – 7:30pm — Short presentation by CEA’s Research Director, Zane Selvans.

7:30 – 8:00pm — Q&A and structured discussion

8:00 – 9:00pm — Free form socializing and discussion.  (And maybe another drink…)

If you want to get the most out of the evening, we highly recommend Utilities for Dummies, a blog post series by our friend Dave Roberts at Grist.

Please register through Eventbrite here. The event is free and open to the public, but space is limited and we need an accurate count of the number of people attending.Hope to see you there!