Contrails from a jetliner. Image courtesy Pixabay/diddi4
There are few, if any, fields of human study for which fieldwork is more fundamental than geology. For many geologists, the solid earth itself is their subject, and this means observations can be made at any given location on the planet. Moreover, the local quirks of different environments almost necessitate a diverse range of study sites for us to fully comprehend the differing processes that govern the world we see around us.
Beyond offering us the chance to make observations in a variety of different locations, fieldwork allows us to test our laboratory models, to interact with researchers from other institutions, and from a personal standpoint can broaden perspectives while exploring and experiencing new places. These positive consequences of exploration and observation are offset by the impact that researchers have on their chosen field sites. ‘Leave only footprints, take only photos’ is a fine motto, but much like Schrödinger’s cat of quantum physics, when we choose to observe the natural system, we have an impact on the subject of our observation.
The scale of that impact can vary widely. When I undertook fieldwork in New Zealand, in field areas culturally significant to the Maori people, we took great pains to limit any long lasting effect on the landscape (with help from the NZ Department of Conservation), taking only small quantities of water samples and keeping to specific areas. The vast majority of field scientists recognise that their own presence can be a source of systematic bias, and experimental or observational design to limit that bias is undoubtedly essential. There’s one big impact that we rarely consider, though; the carbon footprint of travel to and from far-flung locations. Even if the effect of emissions from a single trip is relatively minor, the cumulative effect of climate change systematically influences a great many geological processes.
The carbon footprint of an individual is not always an easy number to pin down. Given that nearly every action we take has some impact on emissions, there are a huge number of variables to constrain for any single person. With some caveats, it’s easier to use data for large populations and average to an individual level. The World Bank provides nation-level data for CO2 emissions per capita, which is highly informative. Unsurprisingly, emissions from Western Europe are higher than the so-called developing world (approx 6.4 tons of CO2 per person per year in W Europe, and 0.8 tons in sub-Saharan Africa for example), while the US values are higher still (16.5 tons).
How do these numbers compare with the emissions from flying? Again, it is difficult to nail down an exact value for airline pollution, with estimates complicated by a variety of aircraft of differing efficiencies in service, as well as non-linear emissions with respect to the length of a journey (taking off burns more fuel, meaning shorter flights have a higher proportional impact – read more here). Roughly, though, airliners emit between 100-260g of CO2 per passenger kilometre. Scaling up, this means a return trans-Atlantic flight puts around a ton of CO2 into the atmosphere per passenger; thus, fieldwork across the world could rapidly make a huge impact on the overall carbon output of an individual.
My own experience is illustrative. As a PhD student in Germany, I felt very fortunate to carry out fieldwork in both Taiwan (c. 9000km from Berlin) and New Zealand (c. 18000km from Berlin); the high rates of erosion in the mountains in those settings made them the ideal location to study landslides and related chemical weathering. However, comparing my emissions from flying over the course of a 4-year PhD purely for fieldwork (probably at least 10-12 tons) with the average emissions per person in Germany (around 8-10 tons of CO2 annually) makes for uncomfortable reading. Not only was this worth more than a whole years’ worth for the average German citizen, but it was far in excess of a level that would, if adopted by everyone, help mitigate dangerous climate change. While it is still under debate what the acceptable level of emissions per person would be, my personal emissions are certainly incompatible with any of the proposed levels, which are often cited as closer to 2 tons per year each.
This would even be true if I had made every other lifestyle change that is often discussed to reduce one’s own ecological impact; a vegan diet, using only public transport, and limiting purchases of new goods; these would not have sufficiently offset the emissions just from fieldwork.
More and more scientists are already reckoning with these moral questions in regards to conferences. A recent editorial about the amount of emissions from the American Geophysical Union’s Fall meeting highlighted that scientists gathered together from across the world have a non-negligible impact on CO2. Such large conferences also present a problem of ‘optics’ as the media might describe it; how are scientists supposed to advocate for a lower carbon economic system when their massed meeting could create such potential harm? Perhaps fieldwork has a less obvious optics problem, given that geologists are scattered around the world, but there remains potential for accusations of hypocrisy to be made.
I’m certainly not the first to be concerned about these issues. When I’ve discussed them before with friends and colleagues, a kind of compromise is often the solution that has been suggested to me: weigh up the costs and benefits of the fieldwork. Perhaps the work in question is directly relevant for carbon capture research, or modelling of the climatic system; in this case, the direct impact of the research resulting from the fieldwork might be more tangible, and in some cases even quantifiable.
For a great many geologists who don’t work on the climate system, these direct comparisons are not possible. In this case, we are forced to make subjective value judgements about how the positive outcomes of our research and findings should be compared with the incremental changes that result in the environmental system from our emissions. These judgements are certainly not unique to geologists, but are perhaps more stark than others given the potential for dramatic climate change to fundamentally alter many surface or marine environments that have been the subject of centuries of geological observation.
I certainly would not presume to make these value judgements for other scientists. We each have our own perspectives, and these may often be highly personal decisions. Moreover, I wouldn’t expect geologists to give up fieldwork lightly, or even at all; it’s so crucial to the science as we know it, and is often the highlight of many researchers calendars.
I would argue, though, that the time has come for us to seriously question whether we can do fieldwork in a more sustainable fashion. We’re often seeking the prime location to test our hypotheses, which may be half way around the world, but instead of forgoing these field sites, we should perhaps ask ourselves: could local researchers take the samples we require on our behalf? There’s an added bonus to this suggestion, too – it could encourage productive collaboration across borders, as well as helping development in economically deprived-but-geologically-interesting countries through the intersection of ideas.
Whether it’s seeking new collaborators in the ‘perfect setting’, or seeking a compromise field-site closer to home, or even to embrace a slower way of travelling (such as trains) there are ways to reduce flight for fieldwork. As earth scientists, we are among the most informed citizens about the potential for catastrophic climate change. It is up to each scientist to decide for themselves whether this knowledge carries with it an imperative to act, but given the global consequences of our actions such an imperative seems more urgent than ever.
Robert Emberson is a science writer, currently based in Vancouver, Canada. He can be contacted via Twitter (@RobertEmberson) or via his website (www.robertemberson.com).