Living Well on a Four Ton Carbon Budget

Environmentally minded Americans recognize that global climate change is the single most urgent ecological and political issue facing the planet.  If you are like me, you want to live consistently with your beliefs about climate change. We all know we need to reduce our carbon impacts. But we don’t know by how much, and most environmental organizations don’t give us a clue what a sustainable carbon footprint would look like.  The rate of global carbon emissions overwhelms us, and makes individual action feel futile.  Giving up carbon emissions entirely seems inconsistent with a contemporary, comfortable lifestyle in the developed world.

But most people share the basic ethical sense that it is wrong to make lifestyle choices that cause harm to other people.  And we know that climate change will cause grievous harm to millions of people around the globe.  It’s easy to blame capitalism and large, impersonal oil and coal companies for climate change, but we can’t ignore our own complicity in the fossil fuel economy when we burn gas to get to work, jet fuel to go on vacation, natural gas to heat and cook, and coal generated electricity to light and cool our houses.  As cartoonist Walt Kelly put it forty years ago, “We have met the enemy, and he is us!”

This is a blog about living a good life with a sustainable individual carbon footprint of about four tons CO2 equivalent per year. The dual, mildly contradictory premises of this blog are that 1) we all share an ethical responsibility to live right now with a carbon footprint that will not cause catastrophic climate impacts to other people, and 2) life should be fun.

I think that an individual direct footprint of four tons per year is defensible as sustainable for a middle class citizen of a developed nation during the phaseout of all fossil fuels over the next few decades.  Some might argue that this is unjustifiably high (it is much higher than a per capita global allocation of the remaining carbon emissions budget), some might argue that it is impossibly low (few people in the US get by on a four ton carbon budget).  I will explain this in greater detail elsewhere.


I plan to use this blog to share my thoughts about the meaning of carbon sustainability, and to share my experiences with lowering my footprint for getting to work and heating and lighting my house, while saving some of my carbon budget for fun!


A Mediterranean Diet Approach to a Low Carbon Footprint

About fifteen years ago I had a really high cholesterol and triglycerides count at my annual checkup. I had never really paid much attention to my diet before that, since I was one of those blessed people who could eat pretty much anything without gaining much weight. Three cheeseburgers for lunch? Why not?

Back then, my GP automatically prescribed statin drugs for every patient with high cholesterol. I resisted. I was too young to have to take meds every day for the rest of my life. But to me, food is one of the essential pleasures in life, and I didn’t want to swear off meat, or any other food group, completely. Robin handed me Nancy Harmon Jenkins’s Mediterranean Diet Cookbook, which was already sitting on our shelf, and it pointed to a way out of my predicament.: A book full of delicious sounding food, all somehow associated with very low incidence of heart disease.

Jenkins quotes this description of the Mediterranean diet from a 1993 Harvard Medical School conference:

Plentiful fruits, vegetables, legumes and grains; olive oil as the principle fat; lean red meat consumed only a few times a month or somewhat more often in very small portions; low to moderate consumption of other foods from animal sources such as dairy products (especially cheese and yogurt), fish, and poultry; and moderate consumption of wine (primarily at meals).

Sounds good to me! As Jenkins puts it “A diet of Mediterranean dishes . . . will be healthful and satisfying but never austere.” Best of all, the med diet didn’t require me to totally give up meat or carbs or fats or anything else – just moderate my consumption of some foods. As an article on the NIH website puts it,

In a somewhat reductionist approach, the traditional Mediterranean diet can be considered as a mainly, but not dogmatically, exclusive plant-based dietary pattern.

Not dogmatically vegetarian! The Mediterranean diet, where red meat is either a garnish in small quantities or a rare treat at a celebration, is pretty good for the climate too, since beef and lamb have about the highest climate footprint among food choices (unfortunately, dairy products have big footprints, too). But part the Mediterranean diet and culture also includes “feast days” – usually religious celebrations, where people indulge in the rich food that is not part of their daily fare, so you can still enjoy these rich foods as a treat.

So that beautiful and savory minestrone soup in the picture above is good for my health and for the climate. But it’s not vegetarian – you start it by frying a little pancetta in the soup pot, and adding beef stock enriches the flavor. I am not dogmatic about vegetarianism. Or my climatarianism for that matter. When climate conscious friends chide me for eating some free range organic beef about once a month (13 lbs CO2 for an 8 oz portion), I just smile and resist comparing my meat eating to their jet travel (2000 lbs CO2 for a typical round trip flight). I might even get on a plane myself on occasion for a really good reason, as long as it fits in my carbon budget. We all deserve our occasional feast day.
After about three months of a Mediterranean diet, together with adding daily exercise to my routine, my cholesterol was back in the normal range.

February Temps Were High But at Least My Carbon Footprint for the Month Was Low


Another month, another month of above normal temperatures globally.  And record highs for my home region in NY.

At least it meant that the backup nasty gas furnace in my house did not come on once all month (we heat with a woodstove fired with backyard deadwood, mostly). That’s a first for the thirty winters we have lived in this house. And we still managed to have a pretty good month for cross-country skiing – by making two trips in the Prius to our north woods cabin.


My total carbon tab for the month came to 340 pounds, which is really low for a winter month. The largest part of this was the gasoline we burned making two round trips up north – that was about 200 pounds of CO2. Natural gas (the water heater still runs) added up to 114 pounds CO2. And I wasted 44 pounds of my carbon budget eating beef (part of this was ordering ribs at a restaurant and expecting pork ribs, but ending up with a beef rib).

With a modest carbon footprint for February, I can look forward to having some to spare later in the year when we make summer travel plans.  But I am still more likely to sail someplace interesting than to fly there.


What The Cold Snap Did to My Carbon Footprint . . .

Looks the Northeast is finally pulling out of the epic year end cold snap that started around Christmastime. Temperatures here in the NYC metro area plunged below zero, and NYC recorded its longest sub-freezing streak (14 days) since 1961.

What does this mean for my personal carbon budget? I spent most of the cold snap at our cabin in the Adirondack north woods, heated with wood, so you’d think I avoided the cold-snap carbon surcharge. But actually, it worked the other way around – not being home to feed the woodstove downstate meant that we had to burn more gas to keep the pipes from freezing in our (mostly empty) house.  Our new state-of-the-art internet connected thermostat only goes down to 50 degrees, so I played a little thermostats roulette, turning the heat off, and watching the temperature remotely to be sure to turn it back on if the house got below 40. We had a nervous stretch when the internet connection to the thermostat went down (turns out the power was out), but we got connected and turned the heat back on in time. We also left an electric space heater running in the cellar as extra insurance against frozen pipes.

I checked my gas meter today – looks like we have gone through 95 ccf of natural gas since my last meter reading on December 8.  This compares to 19 ccf we used in November for cooking and the water heater. So there’s an extra 70 ccf or so I can blame on the cold snap. At 12 pounds of CO2 per ccf natural gas, that works out to about 820 pounds of CO2. My personal share of that is 410 pounds – about five percent of my 4 ton personal carbon budget for the year. That 410 pounds is the GHG equivalent of 20 gallons of gasoline or 15 pounds of  beef.

Meanwhile, at our cabin upstate, we burned through our pile of hand split seasoned firewood much faster than I expected. It was . . . cold. Overnight lows outside were in the minus 20F range. Our little woodstove could not always keep up, and we started keeping track of how much impressively warmer it was inside than outside (seventy degrees!), rather than thinking  about the absolute temperature (don’t even think about it).

Apparently, other wood heated homes in the northeast were also burning through wood piles faster than expected. We are lucky though –  red pines surrounding our cabin include a number of snags – standing dead trees. Many of these have been drying out upright for years, and are dry enough to burn immediately after being cut down.  It is a little bit of a crapshoot though, since many of them are also rotten and waterlogged (actually ice-logged at those temperatures).

We have a tree corer at the cabin, and I had the idea of taking cores and thawing them out before choosing which deadwood to cut down.

There was one nice sized – and dry-to-the-core – pine right near the cabin. It was dry enough to hand cut (mostly) and yielded enough pine logs to heat the cabin for most of a week.

I am back downstate for Spring semester classes, and the temperature is supposed to get close to 50 degrees this weekend, so I think this cold snap is over, and I won’t have to freeze my carbon budget for the rest of the year!

Thanksgiving Warmth

I have always been a little skeptical about those claims that you can heat a super-insulated zero carbon house through body heat alone. I mean, your body heat might keep a sleeping bag warm, but your whole house?

But this thanksgiving gathering was a natural experiment. We haven’t turned the central heat on in our 1937 not particularly well insulated stone house yet. The sole wood stove usually struggleds to get the living room temperature into the 60s when ( like yesterday) the outside temperature is in the 30s.

But by the time we packed twelve family members and guests around the table, the thermostat was in the mid-70s even though the wood stove fire had dwindled to embers. People were stripping off their  fleece.

Apparently, each human body gives off about 100 watts. So our ten guests were the equivalent of a one kilowatt space heater in the middle of the living room. I had a warm and wonderful Thanksgiving! And the turkey in the oven didn’t hurt.


Counting the Carbs For Windfall Firewood and Shipwrecked Beef

IMG_2263Living on a carbon budget means coming up with an accounting system for carbon impacts where no accounting conventions exist . . . yet. Recently I dealt with two personal carbon accounting riddles.

Two weeks ago, my brother-in-law’s sailboat ran into rocks off Barnegat, New Jersey and started sinking (he was asleep and his friends were steering). Fortunately, the Coast Guard quickly came to the rescue, no-one was hurt much, and the boat can be repaired. But when my shipwrecked brother-in-law landed at our house for a few days he donated the contents of his boat fridge, including about three pounds of hamburger and kebobs to our home fridge. Also, last weekend, a neighbor offered about a cord of seasoned but unsplit white oak firewood from a tree that fell down a year ago on her property, and I couldn’t pass it up.

The beef represents about 75 pounds of CO2E (it was grass fed, but that doesn’t make much difference). I am very skeptical of the rationalization “that plane was flying anyway”or “that cow was already dead” for zero counting of carbon impacts, and I like to err on the side of inclusion rather than avoidance.  My general rule of thumb is that “if you pay for it, it’s yours” and “if you choose it when you had a choice, it’s yours” so that plane flight is always on my tab, and the methane laden beef farts are also on my tab when there is a choice of beef or chicken or tofu at the meeting room meal table. My other rule of thumb is “if they are not on someone else’s carbon tab, they are on yours.”

My brother-in-law doesn’t keep a carbon tab.  Actually I don’t know anyone personally besides myself who does.  If he did, he would probably beat my 4T/year budget, since he lives on a small sailboat year round and almost never flies (he was headed south for the winter when his boat hit the rocks). I didn’t choose to have my brother in law leave his spoilable provisions in my house (he has since rejoined his vessel in New Jersey). These cows have already farted their last, and unlike the act of burning fossil fuels to run a car, eating the beef doesn’t add any new emissions. It might even offset some anthropogenic methane emissions associated with an all-garbanzo bean diet. Since I limit the amount of meat I eat for health as well as environmental reasons, I will probably end up choosing or buying less beef on other occasions in the next month, so this shipwrecked beef minimally reduces overall demand for beef. I think I can eat the beef before it spoils as a carbon-free windfall.

Speaking of windfalls, the firewood is a simpler problem. I think it is fair to count small-scale biomass wood heat as carbon neutral, particularly when you are burning deadwood. Burning deadwood can’t exceed the natural regeneration (and carbon recycling) rate of the forest, and leaving the wood to rot instead means that at least some of the stored carbon would be emitted as methane gas. So my windfall wood heat also counts as a carbon freebie. But I am counting the two miles of driving the Prius to move the wood on my carbon budget — works out to less than a pound of CO2.

Under (Carbon) Budget Again – Academic Year Edition


I keep track of my carbon footprint on a regular basis.  My carbon budget goal is four tons of direct impacts on an annual basis. Since the cycle of my seasons follows the academic cycle of class semesters, the start of the academic year in the beginning of September seems like a good time to take stock for a twelve month cycle – better than December 31, which always seems to split one winter season in half.

So I finally got around to checking my utility bill so I could close out the gas part of my ’16-’17 academic year carbon footprint – and I undershot my four ton budget again. My total footprint for the year was about 6500 pounds, or about 3.25 English tons of CO2E. Big ticket items on my carbon tab this year included my share of the natural gas for heating and cooking (nearly one ton CO2E), one round trip flight to Utah to attend the Waterkeeper Conference (also about one ton CO2E), and my share of gas for the Prius when we drove to our mountain cabin upstate or to visit our son in Pennsylvania (a little over one-half ton CO2E).

For all the grief I get from my even-greener-than-thou friends, my occasional hamburgers and steaks only worked out to about 300 pounds of CO2E for the year – about ten pounds of beef for the year. That’s just a little bit more than the 284 pounds CO2E from my share of the diesel we burned in our sailboat.  But that diesel included taking the boat from Charleston to the Bahamas and back to New York, as well as several trips to the ocean and to Block Island. Can’t beat a sailboat for low-carbon hedonism.

I have now kept detailed track of my carbon footprint for two consecutive academic years.  Both years I substantially undershot my four ton budget without giving up anything that is really important to me. It can be done!

The Majestic Beauty of Clean Energy


We made it back to Block Island, Rhode Island last week. I have been going there, on and off, for decades — the first time I visited was in 1972 with an American Youth Hostels bike trip. My second visit was in an open boat, with one of my brothers, in 1975. Then, as now, the island draws me in as an outpost in the sea, beyond the sight of the mainland (at least on a typically foggy day). Still some of the best scenery and beaches in the world, to my eye.  The Nature Conservancy calls Block Islands one of the “last great places” for nature on Earth.


This timeless island changes slowly; the Victorian downtown feels like an early 20th C seaside resort.

So how do I feel about the new wind turbines just offshore, adding a 21st Century techno-backdrop to the historic hotels?

I feel great. Sure, you can see the turbines looming over the town from Scotch Beach, but only if you look carefully. And if you look that carefully, you can also see the oil barges passing south of the Island with their fossil cargo. One might loom over the town more dramatically; the other looms more climatically.

I’ll take the view of the wind turbines any day. And not only that, the turbines (and the mainland cable) means they could shut down the noisy, stinky diesel power plant on the island.

We got to Block Island the old fashioned way — in a sailboat. It took just 29 hours from Nyack to Great Salt Pond — down the Hudson River and out around the south side of Long Island. Only three hours under power. We had to leave extra time on the way back, with light daytime winds (and good overnight winds) in the forecast — but the Atlantic treated us to a shoal of pilot whales and a free bluefish dinner off of Fire Island during our return trip. And a fair tide carried us most of the way back up the River to Nyack, with just one hour of running under power.

Total fuel consumption for the round trip; about three gallons of diesel. My half share of the fuel equals about 30 pounds of CO2 for our vacation at the seaside.


What Does a Bus’s Footprint Look Like?

   I am riding Adiorndack Trailways north to our cabin in the mountains because I am by myself and the carbon footprint of a bus has to be lower than driving alone, or taking Amtrak, right?

So what is the carbon footprint for one bus passenger traveling 180 mikes by intercity bus?

Well, the bus itself probably gets about 6 mpg, so, allowing for detours to stops along the way, that  180 mile trip probably burns about 33 gallons of diesel, or about 660 pounds of CO2 emissions. But how many passengers should I split that carbon footprint with? If I count the dozen or so average number of passengers I counted on the bus, I get 55 pounds – not much better than driving alone in a Prius (3.5 gallons, or 70 lbs CO2) or riding Amtrak (180 miles would be 81 pounds of CO2 based on the UCS average of .45 pounds per passenger mile).

That’s one of the problems of keeping track of your carbon footprint on public transportation – if you count the actual number of passengers on that empty bus or train, you can come up with some atrociously high carbon impacts for your public transport – driving you back into your personal car and negating the hope that public transit can significantly mitigate transport climate impacts. On the other hand, I don’t buy into the “that bus/train/plane was going there anyway so the carbon footprint of riding/flying is zero” cop out – if you are paying to be on the plane, bus, or train, you own your share of the impacts.

You could take the maximum occupancy to get some really attractively low footprint numbers.  I could divide that 660 pounds of CO2 by the 50 seats on the bus and claim only  13 pounds CO2 as my personal share of that trip. But that is not really defensible – no public transit system cannot operate at 100% capacity all th time for every leg of every trip.

I can’t quite figure out the average ridership per bus for Adirondack Trailways – they claim to carry 3500 passengers on 142 trips each day, which would work out to about 25 passengers per trip – but clearly most passengers don’t ride for the whole “trip” – so the actual average is probably closer to the 12 passengers I observed.

I think I will just use the calculator, which gives me 22 lbs co2 for the 180 mile trip by motor coach (.01 metric tons is 22 lbs).  Incidentally, that same calculator gives a zero footprint for the equivalent train trip, which just can’t be right.

On the plus side, the bus was clean and pleasant and on time mostly. It even had high speed internet for a few hours. And it clearly beats the carbon footprint of train or driving alone – it’s just not clear by how much.

No, Having One Child Does Not Add 60 Tons Per Year to Your Carbon Footprint


This chart is making the rounds, and has been picked up by  Grist, the Guardian, and countless other outlets. It makes a good point – enviros tend to focus on small impact personal mitigation measures like recycling or changing light bulbs, and ignore the big impact personal choices, like flying and having a car dependent lifestyle.

But it also claims that having one child adds 60 tons annually to the carbon footprint of an individual in the developed world.  This makes it sound like one of the most basic aspects of human existence — having a family – is the most climate irresponsible thing you can possibly do. To put that 60 ton number in context, the average per capita carbon footprint in the United States is  about 20 tons – the highest in the world. The global per capita carbon footprint possible consistent with holding climate change to 2 degrees Celsius is somewhere between two and four tons per year, depending on whose numbers you use.

So how does one child born in the developed world add three times the US per capita carbon emissions every year?  Does each newborn come with a Lincoln Navigator and a United Airlines Premier Frequent Flyer Status?

The answer is that the one child does not have such an outsized footprint. The 60 ton number in this chart misrepresents the underlying study – which accounts for the carbon impacts of all future generations going out over 500 years into the future. The chart making the rounds incorrectly attributes these centuries of impacts to the life of the current parent.

I looked into the paper underlying the chart and the sources for that paper, so let me try and explain the error the authors make.  The chart is part of a well-intentioned paper by Seth Wynnes and Kimberly Nicholas appearing in Environmental Research Letters, titled “The climate mitigation gap: education and government recommendations miss the most effective individual actions.” The Supplemental Materials for this paper cite one source for the calculation of the carbon impact of having one child in developed nations, a 2009 paper by Paul Murtaugh and Michael Schlax entitled “Reproduction and the carbon legacies of individuals.”

The important thing to understand about the Murtaugh and Schlax paper is that it does not just calculate the carbon impacts of that one child’s lifetime — rather it looks at the carbon impacts of that child, plus the impacts of that child’s child, plus the impacts of that child’s grandchildren, great grandchildren, etc,  out for almost a millenium, with a diminishing share attributed to that irresponsible 21st century ancestor.  The chart below, from the Murtaugh paper, illustrates how the calculation includes future centuries of carbon impacts:

Murtaugh centuries

Actually, now that I look at it, the calculation does not just extend for centuries into the future, it extends “out to infinity.” So the Murtaugh carbon footprint calculations are not carbon emissions that will occur during any individual’s lifetime.

The Wynnes paper cites the Murtaugh paper as its only source for the carbon impacts of child rearing, and give the annualized carbon impacts of having one child in the developed world as falling into a range between 23,700 kg CO2e (Russia) and 117,700 kg CO2e (US) per year, both in its table one and the following chart:

Wynne Chart.png

But none of the number used by Wynne actually appear in the Murtaugh paper!  The Murtaugh paper does include the following chart for all time combined not annualized out to infinity carbon impacts of one child and all of that child’s children’s children’s children’s children’s descendants:

Murtaught Table 2

Wynne appears to have taken these until-the-end-of-time-totals, converted tons to kg, and divided by average life expectancy to come up with their “annualized numbers” – I can’t get the exact same numbers, but it’s pretty close:

annualized co2 child

So Wynnes, et al, come up with their “annual” CO2 impacts of  having “one” child by taking the cumulative attributable impacts of your children until the end of time and acting as if those impacts occur on an annualized basis during the parent’s lifetime. This is highly misleading, at least.

The decision to have children- and how many – is obviously a highly personal choice. But I think having two children per couple – slightly less than zero population growth – is completely defensible as a climate choice. Any argument that the solution to climate change requires the elimination of future generations in order to avoid a backwards attribution of their impacts will not win any converts to the cause.

One last note: the Murtaugh numbers used by Wynnes are based on the assumption that current per capita carbon emissions in each country will continue unabated until the end of time.  There is not enough fossil fuels on the planet for that assumption to be remotely plausible.


Peak Solar!


This time of year, around the summer solstice, is the annual peak for solar energy around here! I have just a few DIY panels on the roof and side of my house – cost me a couple of thousand dollars five years ago. There are too many shady trees in my leafy exurbia to make a full professional installation worthwhile. The four 150-watt panels I bolted down to the roof face east instead of south and only get about four or five hours of direct sun even during the longish days of late June. With luck I average about 300 watts of actual output from my solar roof for about five hours — about 1.5 kilowatt-hours per day.

Not much by home solar standards — my peak solar production is less than a tenth of the annual average solar energy of a typical home installation.  

But it also cost me less than a tenth of what a professional installation would. The panels charge a 12 volt battery bank, which is connected to an inverter that is usually switched on to cover the house circuit with my refrigerator. The system is not grid tied — either the house circuit is running off the panels and batteries, or it is running off the utility grid.  I have no way to return excess solar power to the grid — that would require a professional installation. But the advantage is that I have backup power in case of a blackout. Two more panels on the south side of the house charge another battery bank and inverter that power a couple of floor lamps and the fan for the wood stove.

Most of the year this DIY system produces enough to keep the fridge running totally off solar power.  If it’s a sunny day, this time of year, there’s enough extra juice to charge my electric motorcycle — three days of surplus sun is about enough for one round trip to work.

Works out about right.  Of course, I have downsized the fridge — more on that later.