EXPERT REACTION: Antarctic ice samples reveal 700 years of Māori settlement and burning practices

It is scientifically spectacular to see an analysis of Antarctic ice cores show fire patterns in Aotearoa over the last millenia so clearly. The topic is fascinating, but does it miss what we already know in our research community? The work led me to reflect on diversity and inclusion in science.  A swathe of research tells us that diverse teams create excellent science, and there is gender variation in the author list. Other research has visualised citation and collaboration patterns in science and concluded that research from the Australasia and the’ global south’ is often missing from the work of our European and North American colleagues. Although some well-known New Zealand research is cited here, it remains that other excellent research does not seem to have global purchase.

The authors, based across northern America, Europe and Australia, also apparently lack New Zealand collaboration despite the central topic of Māori burning and fire use.  ‘Helicopter science’, where research is led and conducted by those who live and work far from the subject of their work, is currently under scrutiny in the research community. An important critique is that this approach is likely to miss important insights. Its ethics have also been debated widely over the last year or so, as concerns over the exclusion of different groups from research, including Indigenous peoples, have escalated. Indeed, this issue has been noted by the very journal in which this study is published. Issues that have already been researched locally – from dust transport to Antarctica through to population estimates of Māori settlement -  are often identified by local collaborators who, one hopes, have additionally been building the next generation of researchers in the nation where the focus of the research is situated. All of this leads me to return to this paper, which I found fascinating, and ask – how much better could this have been, were it more inclusive in its approach?

Refractory black carbon, think of 'soot', is emitted into the atmosphere from biomass burning, such as forest fires. Black carbon is important for our climate because it absorbs sunlight warming the planet. Due to the very small size of black carbon particles, a few nanometres in diameter, winds can transport black carbon thousands of kilometres from the location of the fire. Black carbon from Southern Hemisphere fires reaches as far as the pristine Antarctic continent. The record of black carbon in Antarctica ice cores provides a history of past fire activity.

For some time now, ice core scientists have wondered where the black carbon reaching Antarctica comes from. The possible candidates are Australia or Patagonia due to their seasonal biomass burning cycles.

Surprisingly, a new study by McConnell et al. (2021) in Nature suggests that New Zealand has been the dominant source of black carbon to a large sector of Antarctica since the 13th century. An array of black carbon records from ice cores clustered in western East Antarctica and the Antarctica Peninsula were examined over the last 2000 years. Black carbon concentrations in the Antarctic Peninsula record dramatically increased in the 13th century well above previous levels with the highest concentrations in the 16th and 17th centuries.

The authors associate this with the arrival, and land management practices, of Māori in New Zealand. The Antarctic-New Zealand connection was made by comparing the ice core record to a charcoal record from a lake sediment core in New Zealand which is indicative of local biomass burning. While the magnitude of black carbon change is evident in both records from the 13th century until today, the trend is not. Ice core black carbon peaks in the 16th and 17th century. At the same time, the New Zealand charcoal record declines. This disparity leaves me wondering about additional black carbon sources from Australia and Patagonia during this time, changes in the hydrological cycle or changes in the transport processes that drive the variability in the ice core black carbon record. Australian and Patagonian black carbon was ruled out as charcoal records from these source regions increased well before the 13th century.

Ice core records drilled by the New Zealand ice core program in the Ross Sea region, located directly downwind from New Zealand, will provide additional information about black carbon and help answer some of the questions raised by this study. Further geochemical evidence may pinpoint the source of the black carbon by linking the organic chemistry signal in the ice core to specific types of vegetation.

The association of Māori with fire is longstanding.  Mahuika goddess of fire gifted her fingernails of flames to enable us to have fire for warmth; fire for sustenance; fire to provide nutrients for the earth. We attribute and honour Mahuika. She is part of our whakapapa. Her mokopuna Māui attempted to reduce her power by tricking her into giving up all of her fingernails but she was able to outwit him, planting her flame into the trees so that fire would be freely available. Fire also defined our boundaries of authority as expressed in this whakataukī 'ka wera hoki i te ahi, e mana ana anō' meaning 'while the fire burns, the mana is effective.' We claimed occupation of our territories by the principle of ahi kaa, that is, we kept our home fires burning.

Through our Ātua, gods and goddesses, we developed deeply embedded practises and rituals and our relationship with fire was interdependent, reciprocal, beneficial and also very practical. Upon arrival to these lands, we relied on the aruhe or fernroot as part of our staple diet. We relied on the moa and other birdlife for food. Burning became part of our practises; regular burning allowed plants to regenerate and some of the minerals in the ash provided rich nutrients for the land. Regular burning facilitated hunting  and access to hunting grounds. Such practises would be typical for any newcomers creating homes on unfamiliar lands to allow time to become acquainted with seasonal cycles, climatic conditions, finding the best places to lay out their plantations and hence their new settlements or kainga. No doubt some burning would not have been controlled as well as they may have planned, but this can be understood. It is not unlike any other peoples adjusting to new lands and new conditions.

The internationally authored paper by scientists who examined Antarctic ice core records to find that carbon emissions increased significantly from wildfires after Māori first arrived in Aotearoa is devoid of context, devoid of cultural understandings and is yet another example of what we have grown to expect from western science. It relies on measurements, modelling and silo thinking and the paper whether intentional or not, posits Māori as the 'naughty' offenders. Moreover, it reeks of scientific arrogance with its implicit assumption that somehow Māori have a lot to account for in terms of contributing to carbon emissions and destroying the pristine environment of the Southern Oceans and Antarctica. Goodness knows why Māori are primarily emphasised, and for what purpose this article was written. Obviously these authors have not caught up with the positive changes in research and science in this country where Mātauranga Māori within the MBIE Vision Mātauranga policy demands Māori involvement, Māori participation and Māori leadership. This involvement starts from the basic premise that we as Māori will tell our own stories and control our own knowledge. Mātauranga Māori is a living knowledge system rooted in our environmental encounters which was outward looking and relationship based. We are connected in kinship even to fire through Mahuika as the spiritual goddess of fire. Similarly we have relationships with the Southern Oceans and the Antarctica through our stories of voyaging and navigation and food gathering. Our relationships with marine life, bird life and the oceans are well recorded through our intergenerational continuum and held in our tribal lore. These are places to which we also have longstanding relationships where we will not intentionally embark on destructive practises. The principle of kaitikaitanga or guardianship is a mantel of responsibility for us and one we willingly share to improve the wellbeing of our oceans and planet. Please do not distort your scientific evidence nor hide behind the intricacies of scientific modelling to position Māori as the problem. I am sure that you can do better than that.