Ongoing climate change in the 21st century will instigate profound societal transformations in the 21st century. Yet, our knowledge of how such transformations can be achieved in an equitable and sustainable manner is limited. The HUMANOR project investigates historical transformations of mobile pastoralist social-ecological systems (SESs) for clues about which pathways may lead to such transformations. We comparatively study SESs that have undergone profound climatic fluctuations in the last centuries (indigenous Sámi, Nenets, Evenki and Mongolian pastoralists) while maintaining their livelihoods through a host of incremental and qualitative shifts. Although these systems are increasingly being exposed to rapid climate change (e.g. the Arctic warming faster than lower latitudes), our understanding of SES response capacities is limited to adaptations within the current systems. We propose that a long-term focus on human-animal relations and the general socio-economic contexts may illustrate how people can deal with abrupt changes (including massive environmental shocks) and re-create these systems. Our focus is on the complex drivers of social-ecological transformations of recent decades and centuries that include climate variation, land use change, governance forms, institutional change (including legislation and social norms) and markets. We expect to show that although it is an ancient livelihood, still practiced across vast areas of N Eurasia, pastoralism is constantly undergoing shifts in the nexus of feedbacks between humans, animals and the environment. This comparative trans-disciplinary study is performed across several timescales (centennial changes since the Middle Ages- marking reindeer domestication in Fennoscandia and Siberia and the height of the pastoralist Mongolian Empire, and decadal changes since the mid-20th century) in order to illustrate the historical context of change and provide key insights into people as active agents or passive receptors of change. For instance, we know that even at low human population densities, large livestock herds can alter ecosystem structure and function but we know comparatively little about how social, economic and political changes foster or impede deliberate, desirable changes in the ecosystems and societies underlying these SESs. We propose that projecting future transformations will benefit from the retrospective partitioning of: (1) socio-economic and political from climate drivers over decadal scales; and (2) human-animal agency from climate drivers over centennial scales. We use an interdisciplinary mix of methods to first reconstruct historical human-animal-environment relationships and environmental histories by documenting current oral environmental histories (myths, legends, life stories) and environmental reconstruction from pollen records and other soil signatures. We use indigenous residents current environmental knowledge to uncover the recent changes (climatic, vegetation, etc.) in their environments and participant observations to uncover the complex socio-economic realities of their SESs. Our analysis draws strength from: (1) contrasting SESs across diverse geographic scales; and (2) accounting for heterogeneous perceptions of risk concerning the future viability of (reindeer) pastoralism in the European Research Area. We envision our project making a significant contribution to the design of ethical and sustainable transformations of SESs in Europe and beyond.

The TundraTime project will address climate change impacts in tundra ecosystems including how warming is shifting tundra plant phenology - the timing of life events such as bud burst or flowering - and productivity - the increase in plant growth and biomass over time. We will answer the fundamental research question of whether climate warming is leading to longer tundra growing seasons and thus increasing plant productivity in the Arctic, with important implications for carbon cycling and wildlife. Critical knowledge gaps in the field of global change ecology are what role the high latitudes will play in the global carbon cycle and how Arctic food webs will be restructured in the future with accelerated warming. A critical unknown is whether shifting plant phenology is altering tundra carbon cycling and wildlife habitats. Projections of climate feedbacks from high-latitude ecosystems remain uncertain as we do not yet know if carbon losses from warming soils will be offset by increases in tundra productivity. Tundra plant responses to warming could be key for understanding the fate of wildlife populations in a rapidly changing Arctic. Forty years of satellite and field observations have revealed widespread changes in the tundra's surface that protects large stocks of frozen carbon below. Field studies indicate that plants are coming into leaf earlier in spring, bare ground is becoming vegetated, and plants are now growing taller. While there is scientific consensus that climate change is reshaping Arctic ecosystems, great uncertainty persists about what the greening observed from space means in terms of change on-the-ground. The TundraTime project will answer the fundamental research questions of whether climate warming is leading to longer periods of plant growth and increases in plant productivity in the Arctic. We will test specific hypotheses of whether tundra ecosystems are experiencing: A) increases in productivity, B) shifts in phenology and C) asynchrony of above- and below-ground plant growth. To explore these questions, we will integrate high-resolution drone and time-lapse camera imagery with satellite and in-situ data from 12 focal Arctic research sites. Our findings will inform biome-wide projections of tundra vegetation change and global-scale predictions of climate feedbacks to unprecedented rates of warming. If tundra plant productivity is responding directly to the warmer and longer Arctic growing seasons then tundra productivity will trap more carbon in tundra ecosystems and restructure wildlife habitats. However, if instead tundra plant growing seasons are shifting earlier, then projections of increases in tundra vegetation with warming may be overestimates and earlier timing of key forage could alter migratory behaviour and ultimately wildlife populations. And, if the above- and below-ground responses of tundra plants are asynchronous, plant growth in the now extended snow-free autumns could instead be occurring below ground, which would overturn how satellite data and Earth-system models estimate plant productivity and carbon storage in warming tundra ecosystems. The TundraTime project will test the drivers of Arctic greening by resolving the uncertainty around what role shifting plant phenology plays in the increased tundra productivity with warming. This research will bridge critical scale gaps to resolve the uncertainty between satellite and in-situ observations of changes in the timing of plant growth with accelerating climate warming.