Brad Pitt: One of the ways individuals can reduce the impact of aviation emissions is to buy carbon offsets every time they fly. Around $25 can offset the amount of carbon released per passenger during a London to NY roundtrip. But most people don't know how carbon offsets work or how to purchase them
Mike Mason, Founder and Chairman, ClimateCare: Ten years ago we set up to try and develop a mechanism for getting ordinary people to be able to do positive things about the climate that were measurable, that were deliverable and related to their own lives. So we set out to create a voluntary carbon market.
David McMillan, Direct General, Eurocontrol: A number of airlines now are offering voluntary offsets schemes to their passengers; where they say if you want to offset the cost of emissions that you personally will be responsible for as a passenger on that aircraft. It will cost you an extra few lbs. But if you add that for all the passengers on the aircraft and use that to do something sensible like buying some carbon reduction schemes somewhere else in the world, it has a real impact.
Mike Mason: The actual measurement is the least difficult of all the issues. If you swop an incandescent light bulb for an energy efficient light bulb, you know exactly how much electricity you save and you know how much the grid emits in producing that and you can do it, it's a simple sum. Much more difficult is making sure what you're doing, first of all is additional this is the jargon or additionality. In other words, what you're doing is going above and beyond the existing policy the existing customs and practice., and the emissions aren't being counted by someone else. So for example, if we do something in the UK they will be counted by the UK government, which is not our objective, our objective is to go above and beyond what the UK government is doing.
The other piece that piece that is quite difficult also is to make sure we avoid leakage. Take for example avoided deforestation; deforestation is a huge source of green house gas emissions, but if you just put a fence around the forest and say "ok guys no more chopping the forest down anymore", without removing the source of demand, than all that happens is they go and chop down a forest somewhere else. So that is the other problem, dealing with leakage, dealing with problems where you don't get that kind of effect.
Brad Pitt: Money from offsets is used to fund energy saving projects in the developing world. These projects reap other benefits for the community, like employment and better health.
Mike Mason: There are two kinds of projects; there are those which have environmental benefits in terms of reduced emissions such as wind farm. But may not have any particular local benefit. On the other end of the scale this is a good example of a piece of low-technology intervention that we're using in Africa, in Uganda in fact., that's why its painted in the national colors of Uganda. This is an improved cook stove, its not the worlds most improved cook stove but its made locally using appropriate manufacturing techniques so that local people and build them and repair them. What distinguishes this from the stoves that many people use at the moment is that there's a ceramic liner in here, which keeps the heat in, which reduces hugely the amount of fuel you need in order to operate and cook your food. It also has controlled air holes there, which makes sure enough air, comes in to burn the fuel properly. A stove like this can reduce emissions and fuel consumption by 40% or more. Its very simple, obviously it isn't a solution to a global problem, but a quarter perhaps a third of the worlds population cook on very poorly made cook stoves which cause blindness and respiratory illness as well as causing huge amounts of pollution.
I speak to senior people at companies, I speak to ordinary audiences of employees, and when you explain to them the back-story the issues behind climate change they all come away thinking "good lord, is it really that bad". And if you could capture their intent the moment they walk out of that room we would have solved the problem. But they go back to their desk and the same pile is in the in try and the same problems face them at home and within 24hrs they've moved on. This is such a big issue, that people don't seem able to comprehend that it affects everything they do and that when they walk out of the room they should start behaving differently. Its making demands of people that are bigger than they can cope with. And some how what we have to do is to ease that transition, don't face them with a cliff, face them with a gentle ascending path that they can climb up.
I would dearly love to see every airline operator required to either include offsets in the price or to offer them as an opt-out. In other words you have to tick the box is you don't want it. We've got to start offsetting we've got to do it today, its easy to do it today and there are plenty of opportunities to do it. You and I share one planet, and we haven't got a spare one.
Additional digital shorts from the e2 Series:
Seoul Reengineers a Freeway Into a Stream
Portland, A Global Model of Transit Oriented Development 
London's Transportation Transformation for the 2012 Olympics