Lots of companies, schools, cities, and other establishment are making big claims about becoming carbon neutral. First of all, what exactly does that mean? To be carbon neutral is to reduce your carbon footprint to zero by participating in activities that offset the carbon emissions you may have caused. Carbon emissions contribute to the depletion of the ozone layer, which leads to human-induced climate change.
The beginning step is to use a carbon calculator, like the one at http://www.epa.gov/climatechange/ghgemissions/ind-calculator.html, to estimate how much carbon you are emitting. Where you can, try to reduce your emissions before committing to becoming carbon neutral. To be carbon neutral, you must offset the same amount of carbon that you are releasing into the atmosphere via your habits and activities. To do this, you can:
- Plant trees. A tree absorbs up to 1 ton of carbon during its lifetime. Even planting a garden or new grass where there is none will make a difference.
- Purchase carbon credits online. You can do this at www.carbonfund.org, and a number of other websites. This guarantees that, somewhere on the planet, your carbon emissions are being offset. Carbon credits are considered an income tax deductible donation for individuals.
- See websites like www.flyneutral.org to purchase carbon offsets for emissions related to air travel. Many airlines provide this service online and offer the option as you are purchasing your tickets.
Written by: Melissa Kullman, class of 2014
You say that:
“Carbon emissions contribute to the depletion of the ozone layer, which leads to human-induced climate change.”
Well, certainly the depletion of the ozone layer is not a major (or really minor) driver of global warming. The US government says so (since this site sequesters weblinks go to esrl dot noaa dot gov forward slash csd forward slash assessments forward slash ozone forward slash 1998 forward slash faq9 dot html). In it they say:
“Ozone depletion and climate change are linked in a number of ways, but ozone depletion is not a major cause of climate change.”
You will find similar evidence from the Union of Concerned Scientists.
Do CO2 emissions cause the ozone layer to be depleted anyway? I cannot find evidence that CO2 is a CFC and that causes the ozone layer to deplete. Can you send me a source for that? My understanding of carbon dioxide chemistry is that CO2 is an extremely stable molecule – which is one reason it is a problem for global warming – it does not easily dissipate in the atmosphere – this is also why various technologies to sequester carbon such as creating co2 scrubbing “trees” are so costly.
As far as planting trees, remember that this carbon is ultimately released when the tree dies, so at best we delay emissions by a while. We each produce 26 tons of CO2 each year btw. Sometimes planting a garden can make more GHG emissions possible, as moving around the soil releases some GHG that are more harmful than the CO2 itself.
As far as carbon offsets, there is a developing literature to investigate whether they are, in fact, offsetting anything. In your post you say “guarantees” carbon is being offset somewhere on the planet. This is most certainly not the case – a recent paper (or more) by Michael Wara of Stanford, which has been covered by NPR, the Economist and other outlets shows some pretty damning evidence here.
Finally, how do the purchase of these offsets, supposing that they actually happen for activities that would not have happened otherwise, compare to the damage inflicted by CO2?
The IPCC 4th assessment report (the one Michael Mann contributed to, along with earlier ones) has a midrange damage estimate of something around $30 per ton of CO2 emitted. This is the monetized value of the health impacts, damage impacts, of a warmer planet under the expected warming scenarios. Do typical offsets charge less than this per ton reduced?