The curious (or suspicious-minded) among you have occasionally wondered about our carbon footprint calculator’s claim that one gallon of gas turns into about twenty pounds of carbon dioxide exhaust. Let’s walk through the math.

Short answer:

When you burn something, it might feel like you’re turning it into lightness, air, nothingness. But what you’re really doing is simultaneously vaporizing it and chemically bonding it with oxygen in the air. It’s the weight of that oxygen that makes up the difference.

Carbon dioxide — or CO2 — is one carbon atom joined to two oxygen atoms. Carbon dioxide. Oxygen is a little bit heavier than carbon, so when you stick two oxygen atoms onto every available carbon atom, you end up with an amount of CO2 that is roughly triple the weight of the gasoline.

Long answer:

One gallon of gas weighs about 6.25 pounds. The weight fluctuates with temperature and octane, but this figure is good enough for government work.

Let’s pretend that gas is entirely made up of octane (more properly referred to as 2,2,4-trimethylpentane). It’s not, but that also doesn’t really matter for our purposes. Octane contains 8 carbon atoms (hence the oct- prefix, like Dr. Octopus) and 18 hydrogen atoms. Carbon has a molecular weight of 12 and hydrogen has a molecular weight of 1, so octane has a total molecular weight of 114 (8 x 12 + 18 x 1).

Oxygen has a molecular weight of 16, so CO2 has a total molecular weight of 44 (12 + 16 + 16). Every molecule of octane makes 8 molecules of CO2, with a total molecular weight of 352 (44 x 8).

6.25 pounds x (352 / 114) = 19.3 pounds

Et voila! All it takes to convert one gallon of gas into 20-ish pounds of carbon dioxide is some highly confusing algebra!

Bonus material:

Gas doesn’t burn 100% cleanly. You also get some carbon monoxide and other nasty stuff coming out of your tailpipe. But that doesn’t really affect our math very much. The official World Resources Institute conversion rate that we use in our carbon calculator is 19.564 pounds of CO2 per gallon of gasoline. Although we round this number to 20 pounds when we speak informally of the amount of carbon dioxide from one gallon of gasoline, all of our online calculators use the more precise figures.

Also, bear in mind that the 19.564 pounds of CO2 are just the direct result of burning gasoline. The process of extracting, refining, and transporting the product adds an extra few pounds per gallon to the actual environmental impact of filling your gas tank.

Finally, your exhaust is quite a bit heavier if you count the steam that is generated. Those 16 hydrogen atoms attached to every octane molecule have to go somewhere. They combine with oxygen to create water (H2O). Every gallon of gas creates roughly 8 pounds of water vapor. And water vapor is, believe it or not, a greenhouse gas, although not one we generally concern ourselves with, for a variety of reasons.

Aren’t you sorry you asked?

Re-think: When was the last time you stood back and took a hard look at your event model? Rethinking is about taking stock of your event, the format you use and how participant needs are evolving. Could you improve services, expand your reach and cut carbon by exploring hybrid formats? One technology event has reduced their overall carbon emissions by 10,000 metric tons by segmenting their audiences for virtual or in-person participation. Sales and C-level attendees are invited to participate in person while technical experts receive session content online. Could your event and the planet benefit from doing the same?

Reduce: Cutting waste is not just about helping the environment, but the bottom line as well. Consider these examples: selecting venues and hotels within walking distance and a destination with good transit infrastructure saved one 40,000-person event $500,000 and 36,000 lbs of emissions over three years. For another small 400-person event the same decision translated into $3,000 in savings. Asking how you can reduce at the beginning of your planning process can help save in many ways.

Reuse: From signage to china service and carpet, reuse also pays. Generically branding and removing event dates from banner signage helped one organization improve signage reuse to 37% and saved $188,000 in a single year. Asking for bulk re-usable water stations can also save organizers $2.50 per attendee while cutting water consumption in half. Reuse of 1,000 square yards of tradeshow carpet can reduce greenhouse potential by 31,000 lbs of carbon dioxide.

Recycle: While many venues and hotels in the USA provide basic recycling, most planners don’t realize that the quality of these programs varies significantly. Few hotels extend recycling to guest rooms. 20-30% of landfill waste from events is often organic, which could be composted, making zero-waste a great goal, but one that is not yet widely achieved despite marketing claims. Buying recycled and asking deeper questions about venue recycling are steps planners can take to be better informed and improve event sustainability.

Responsibility: And lastly, but definitely not least, we need to recognize that there are impacts of events that are not possible to avoid. This is where the important step of offsetting comes in: it is your opportunity to be accountable for the carbon footprint that cannot be avoided through the methods above. Making an informed choice about your offset provider to select permanent, additional and verifiable projects that fit with your organization’s mandate is important.

In 1986, I packed my parents’ Impala and made the trip to college. I had one trunk, a clock radio, a boombox, and some toiletries. Back then my environmental impact from electronics on the campus was less than 3 kWh or about 3 lbs of CO2e per day, and that was similar to most of my classmates. Now, college dorm rooms look pretty different. Today, students are showing up to school with enough clothes to dress a village, a laptop, a printer, a flat screen, an iPod dock,  a gaming systems, a smart phone, and a mini-fridge. These electronic devices draw power even when turned off, and this vampire power can account for up to 10% of energy use (US EPA).

NYU Green put together a great infographic showing the annual energy usage of residence halls, a tremendous difference from 25 years ago. 

Collectively, business travel creates a sizable carbon footprint for conferences.  Conferences can produce 1,000 – 2,000 lbs of CO2 or more per attendee, depending on the event. That adds up pretty quickly. The carbon footprint of an event primarily consists of activities from three areas:

 Flight: An in-person event like conferences requires a number of plane trips. A typical cross country flight emits 2,145 lbs of CO2.

 Car & Cab: Traveling 40 miles, to and from the airport or in a cab around town, will emit about 40 lbs of CO2

 Hotel: Each night spent in a hotel creates 75 lbs of CO2 from fossil fuel derived electricity.

While more event planners are addressing event site emissions through the purchase of RECs and carbon offsets little is still being done to mitigate the carbon footprint of the attendees. Many companies are struggling to build a solution into their event plan. At TerraPass we have helped several conferences address this issue, from our experience the solutions produce fairly standard results that are easy to replicate. When planning a conference there are several different options for addressing emissions created by attendees, some are very effective and others are not. As efficiencies go, conference coordinators address venue, food, local transportation, and water regularly but around 90% of emissions from conferences and events are created by attendee travel.  How does an event continue to grow and do business while considering the world around them?

If you are interested in achieving 100% attendee offset there is a simple solution, but it requires the event host to be a leader in the field of emissions reductions. Building the carbon offset into the price of the event not only requires participation it also alleviates the pressure of the attendee to figure out the solution to their emissions problem. Many people have good intentions to take responsibility for their footprint, but do not have the tie or expertise to follow through on their intentions. By building the price of the offset into the event price a company is showing they have taken the leadership position and done the work for the attendee.

The second most effective way to encourage conference and event attendees to offset their emissions is through an opt-out program. We generally see around 15-20% of attendees offsetting their trip with this option. Like building in the offset price the event organizer is making offsetting accessible for the attendee.  As an add-on, however, this cost is not always an approved expense, thus dropping the take rates.

Another option is to create an opt-in program, but these programs generally only see 1-2% of attending opting-in. Here the burden is placed on the attendee to know what a carbon offset is, make the decision to participate and get the expense approved by their company.

Creating a successful offset program for your conference can have a meaningful environmental impact and help further the sustainability goals of your event and your company.

Like a frog in slowly heated water, we don’t tend to notice momentous changes happening right around us if they’re happening slowly enough.

One such change, a big, momentous, but oh-so-slow change, made itself visible just briefly last month and it’s worth highlighting.

Deep in the bowels of the Securities and Exchange Commission, a Feb. 2013 letter revealed some new thinking regarding public company disclosures of business risks due to climate change.

Here’s what happened:

PNC Bank asked the SEC for permission to exclude a shareholder resolution regarding disclosure of climate change risks, from its annual meeting ballot.  This is fairly commonplace. Activist investors submit hundreds of resolutions to companies every year, but companies can choose not to forward such resolutions to shareholders if (among other reasons) the resolution addresses topics within the ordinary authority of the company’s Board of Directors.  To ensure their judgment on this point passes regulatory muster, companies may ask the SEC to “concur” with their decision.

This particular shareholder resolution asked PNC to assess the greenhouse gas emissions resulting from its lending portfolio, as well as its exposure to climate change risk in its lending, investing, and financing activities. PNC decided to exclude the resolution from its ballot, and asked the SEC to concur.

In a surprise move, the SEC staff did not concur.

Instead, PNC was told that climate change represents a “significant policy issue” for the bank and its shareholders.  That deserves repeating.  The SEC said, not that climate change is important in general, but rather that climate change is important, for banks.

This is a big deal.

The world around us is changing: financial regulators now view climate change risk as significant even for companies whose own operations are limited to office space and purchased electricity.

But as noted above, this is a slow change. It doesn’t mean that banks need to start calculating greenhouse gas emissions from their lending portfolios, much less that they need to do anything about what those calculations reveal.

Instead, it’s one more reason for companies to assess more broadly the potential effects of climate change on their business, including in that assessment their supply chain, and their customers.  If that broad assessment reveals important risks –regulatory risks, energy price risks, weather-related risks – then perhaps it’s time to speak up.

To start, The Environmental Protection Agency (EPA) and other groups, which are critical to creating and enforcing emissions limits, are faced with severe budget cuts. The EPA’s Air program, which addresses air pollution from mobile and point sources, has lost $100 million in funding.  Moreover, the EPA’s enforcement budget will be chopped down by $64.5 million, which is crucial to monitoring pollution levels, and penalizing emissions violations. State and local environmental groups may also suffer from reduced grants, which are crucial to accurately monitoring local pollution levels, which, without proper monitoring, could be detrimental to the environment and public health.

In addition to cutting funding for programs that limit and monitor emissions the sequester cuts clean energy research funding and could cause the U.S. to fall far behind the rest of the world’s renewable energy technology. $254 million is set to be cut from the Department of Energy’s science program, $91 million of which will be taken from the DOE’s energy efficiency and renewable programs. This means that automobile efficiency research funding will be cut, and lessen the U.S.’s competitiveness in the international high efficiency vehicle market.

China and Europe are investing in renewable technologies at a growing speed, and if the U.S. falls behind, the US renewable energy market could suffer. Government investment is critical to funding renewable energy research, and producing cost efficient renewable energy that will be competitive on a global scale. In order to stay in the game, the US needs funding as the industry continues to grow.

The National Parks Service, which is essential to the preservation of pristine environments in the U.S., will suffer from major funding cuts totaling around $110 million, eliminating more than 200 wildlife management jobs, putting vulnerable creatures and habitats at risk. Yellowstone National Park has already been affected by the budget cuts, as they have been forced to keep their doors closed, and delay the open season in order to preserve their precious funds.

The sequester was put into place to reduce the deficit, but ignores the need to close the tax loopholes for big oil companies that benefit from federal subsidies. The Wilderness Society and other environmental groups have identified more than $760 billion in additional tax revenue from unnecessary tax expenditures for fossil fuels. Big Oil’s tax money has the potential to take a chunk out of the federal deficit, will instead continue to fund oil drilling and fossil fuel extraction. On positive note, the Sequester includes the new limits to the DOI’s ability to issue drilling permits, which could slow offshore oil drilling, limit our dependence on fossil fuels, and bring urgency to the United State’s need for more clean domestic energy.

Democrats and Republicans have made efforts to avoid the Sequester, but Congress is still nowhere close to coming to an agreement. Obama  has proposed a plan that would replace the harsh budget cuts, and reduce the deficit with a mix of carefully-planned spending cuts and new revenue from closing tax loopholes for corporations and the wealthy. We hope to see changes before the funding cuts lose the attention of our leaders that they deserve, which could make crucial renewable energy research to come to a standstill, or cause the U.S. to take a few steps back in terms of climate change policy.

How are you spending this Valentine’s Day? Tell us in the comments below.

Climate change was a central topic in Obama’s inauguration speech in January. We hope that this means that more will be done in the fight against climate change, but politicians have failed to live up to their promises before. Can we expect to see the decreased fossil fuel consumption and foreign energy dependence, and a rise in domestic renewable energy in the next four years? How much change can we expect from Obama in his second term?

Obama’s previous State of the Union addresses focused on the economy, the deficit, and foreign policy. As the nation crawls out of the current recession, will climate change policy have the chance to take center state? Post your opinions in the comments below.

Each month in 2013 you will have the opportunity to support a specific project through the purchase of carbon offsets. This month we are excited to feature Greater Lebanon Refuse Authority (GLRA) located in Lebanon, PA.

Why GLRA is a great project:

• Overall commitment to the environment. In addition to their landfill gas to energy project they have also installed a natural aquatic life treatment system to filter lechate from the landfill, thus creating a biodiverse habitat for local wildlife while discharging clean water from the system.
• Overall commitment to promoting renewable energy: The landfill has built a Renewable Energy Education Facility to fulfill their primary goal of promoting sustainable energy sources and fostering environmental education and stewardship.
• Overall commitment to the community: The landfill has constructed a walking trail that encompasses part of the historic Union Canal. The Union Canal operated in the 1800′s as a waterway transportation through the Lebanon Valley.

Please join TerraPass in supporting this exemplary project bycalculating your carbon footprint and purchasing offsets today. The window to support this project will close at 6PM PT, 9PM ET.

Do you ever wonder how an offset comes to be? Terrapasser, Nick Facciola, talks about his visit to GLRA to verify the project’s carbon offsets.

Weekend driving can still emit tons of carbon (pun intended)
By: Lauren Rosenberg

TerraPass offsets all emissions generated from all employee travel and commutes to our headquarters in downtown San Francisco each year. Most of us are carbon footprinting geeks, always eager to calculate our personal carbon footprints, from activities like weekend driving, flying, and home energy use, to make sure that our footprints are covered across the board. When we saw the findings of our most environmentally-committed  colleague, Nick, we were a little surprised to see how much driving contributed to his total footprint.

Nick is committed to taking public transportation, eating a whole-foods, plant-based diet, and riding his bike around town on the weekends. He lives with his fiance, Jamie, just across the Bay Bridge  in Oakland. She works from home, so their weekday driving is low if not zero. Even with their earth-conscious lifestyles, the second largest source of emissions for them was from driving: a whopping 39%. How does that work out?

They share her 2000 Honda Accord, which gets average milage for a midsize non-hybrid car; around 25 miles per gallon (MPG). Their annual driving, primarily from weekend driving and road trips around California,  is only 7,000 miles per year, or about 3,500 miles per person per year.  The average American drives 12,000 miles per year, and the average MPG  of vehicles in the US hovers around 21, pushing the average driving footprint up to 5.1 metric tons (about 11,000lbs). This puts Nick and Jamie at about ⅓ of the US average, yet they still produce about 7,000 pounds of carbon each year.

As expected for frequent domestic travellers, flying was the biggest contributor to the couple’s carbon footprint. Five round-trip cross country flights for each of them make flying produces nearly 8,000 pounds of CO2, or 42% of their total emissions. Natural gas use for heating came to 10%, electricity 9%.

So should we stop visiting our grandparents over the holidays, or travel to our favorite vacation spots via paddleboat? Of course not. We can still live a full life while being conscious of our actions, and taking responsibility for your carbon footprint.

If you are not lucky enough to have your the offset of your commute carbon footprint sponsored by your employer, consider finding ways to lighten your footprint on a daily basis. If you don’t live in a place with ample public transportation, walk or bike to work. Public transportation is the most efficient method for longer-distance commutes, followed by carpooling. For air travel, always fly non stop, and swap business travel for video conferencing whenever possible.

What was your 2012 carbon footprint? Have you lowered your emissions in the past year? If so, what lifestyle changes did you make?