The calculation below is indicative of the level of carbon footprint relating to attendance at the 2018 conference. To this end I have estimated the total accumulated travel of those attending the conference to be 6087km (3782 miles). Using the calculator on www.carbonfootprint.com this is the equivalent of generating 0.56 tonne CO2, which is 305m3 CO2 in volume (assuming travel mainly using fossil fuels). The below is then all just worked through by way of example.
Apparently a mature tree absorbs 22kg (c 50lb) of CO2 per annum, and so the 2018 conference CO2 would nominally require the growth of 25 trees over a year to counteract this, in the sense of the CO2 being locked up rather than freed into the atmosphere as a greenhouse gas. Or, looked at another way and on the same time-scale as the meeting itself (ie 1 day), then about 9000 mature trees would be needed (or about 450 acres of woodland) for real-time neutralisation of effects of this travel in terms of its CO2 generation in real time.
In common with most organisations, the PCRG has no land to be growing trees on, and this is where the carbon offsetting economy has been developed, where, for instance, various tree-planting schemes in the UK, and often also in other countries, get the benefit of being supported as a way of countering the defined negative effects of burning fossil fuels. The calculator seems to work on 7 trees/tonne CO2 being ‘adopted’, and so, balancing the 2018 conference CO2 emissions, would represent about 4 tree’s worth. Looking at the various schemes being offered, it seems that this could be offset by paying £5-£10 to a tree-planting project (either overseas or in the UK).
In the light of current concerns about emissions and pollutants it does seem sensible to start developing some awareness of this impact, which then provides a background context for possible action. Any such action could take various forms, such as a payment as outlined above. An extension of financial accounting, to also include environmental impacts like this, may also now be a desirable development and reflect greater social responsibility (as is already done by some organisations). Perhaps this is something else for the treasurer to think about!