Recent trends in sustainability research have particularly propagated transdisciplinary approaches in knowledge production. These new modes of knowledge production seek to deconstruct universalist principles and epistemic authorities from positivist research approaches. The potential of replicating existing power dynamics into these transdisciplinary spaces has, however, not sufficiently been critically questioned yet. This study proposes that transformative change in development of African cities requires a deconstruction of these power dynamics, that current transdisciplinary sustainability research is not yet sufficiently engaging in. To examine the power dynamics, the study applied a decolonial lens in its analysis. In a novel approach to contesting climate knowledge, the study sought to deconstruct the foundational concepts that are operationalised in the transdisciplinary knowledge generation. The analysis focused on tracing assumptions to identify imaginaries, that construct the geopolitical space and condition knowledge politics within a transdisciplinary research programme in Windhoek, Namibia. It further sought to reveal the mechanisms in the programmatic research design that condition epistemic authorities and subjectivities in the collaborative processes. Power dynamics were traceable through imaginaries as well as the evidencing of epistemic authority. Two overarching imaginaries could be traced, which are based in the construction and engagement of the geopolitical space in Windhoek: the imaginary of the social impact and desirable future and the imaginary of the sciencepolicy interface. Both imaginaries were underpinned by the vision of transformation, whose operationalisation revealed to be instrumental in determining the actual transformational potential in contrast to the envisioned one. The analysis indicated the concept of transformation to be an inhibiting factor due to uncontested power dynamics that were replicated in the transdisciplinary space. Epistemic authority was especially evident in connection with the climate information that was generated to inform the knowledge co-production. A contestation of authoritative knowledge was evident with regards to contextualising the information for present and future climates in Windhoek. However, the scientific climate information itself was not questioned for its authority. The conceptual design of the stakeholder engagement revealed to be the main mechanism that created subjectivity. The study concluded with an exploratory section, an ‘epistemic disobedience’, which engages the principle of Walking With that is used by the indigenous activist movement of the Zapatistas in Mexico to create a vision of a new world. Walking With is used to reconstruct a vision of a decolonial approach to generating climate knowledge in an African urban space. This exploration further exemplifies a dimension of decolonial criticism, which is the importance of going beyond deconstruction towards fostering decolonial thinking.

Includes bibliographical references / Climate change poses a major threat to living organisms, with maximum temperatures expected to continue to rise over the next few decades. Hot desert environments are particularly at risk because they experience high environmental temperatures, scarce vegetation, low productivity and unpredictable water sources. Endotherms such as birds face the challenge of maintaining a stable body temperature while avoiding dehydration. This study was carried out in the southern Kalahari, in South Africa's Northern Cape, where about 50% of bird species (36 species) depend on free-standing drinking water. Livestock farms within this area provide artificial water points, which benefit birds as well as livestock. This study determined the role of shade and cover in the use of these artificial water points by birds. An experiment was conducted at six waterholes using the Before-After, Control-Impact (BACI) design. After an initial baseline was established, three waterholes were shaded while the other three were left unshaded. Camera traps were used to record the pattern and intensity of water use by bird species at different times of the day and at varying air temperatures. A total of 36 bird species drank at the water holes, but data analysis was confined to the ten most abundant species. Of the ten, six species responded to the presence of shade/cover, with four species reacting positively (Cape Glossy Starling Lamprotornis nitens , Red - headed Finch Amadina erythrocephala , Black - throated Canary Serinus atrogularis , and Laughing Dove Spilopelia senegalensis ), four showing no significant change in drinking patterns, and two showing a decrease in visitor numbers when the site was shaded (Cape Turtle - Dove Streptopelia capicola, Namaqua Dove Oena capensis). This suggests that providing shade at waterholes is not a universal solution to the problem of increasing heat stress experienced by birds coming to drink. Certain species such as the Laughing Doves and Cape Turtle-Doves avoided waterholes during the warmest time of the day while the Namaqua Doves were frequent visitors at this time. However, the Laughing Dove took advantage of the shade provided at midday (warmest temperatures) as their numbers increased. The Red-headed Finch and Black-throated Canary also increased at water holes with temperature irrespective of the time of day. These patterns imply that the provision of shade modifies the behavior of some bird species in response to predation risk or heat stress. These species utilized shade at different times of day and with varying intensities as temperatures rose.

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The overarching goal of this study is to investigate the nature of precipitation variability in tropical South America over interannual to orbital timescales during the last 50,000 years. In order to address high-resolution climate changes over modern and ancient timescales, this research integrates instrumental records with model simulations and proxy reconstructions from geologic archives. The specific region of focus is the central Peruvian Andes (12°S, 76°W), where recent temperature and precipitation changes are magnified and glacial retreat has accelerated. Monthly output of modern simulations from isotope-enabled global circulation models are validated using precipitation and temperature observations from the Peruvian Meteorological Service (SENAMHI). Interpretation of model results is focused on analysis of the oxygen isotopic composition of precipitation, which also can be readily measured in geologic archives. Interannual variability for the last 133 years (1870–2003) demonstrate that precipitation in central Peruvian Andes is largely influenced by upstream variability, primarily related to the intensity of the South American Summer Monsoon. Over decadal timescales, the sea surface temperatures in the tropical Pacific Ocean and the North Atlantic Ocean also affect the strength of regional summer precipitation. Speleothems (cave samples) were recently collected in the central Peruvian Andes and are used extend the climate record through Holocene and Last Glacial periods. Two stalagmite samples from Huagapo Cave demonstrate that an intensification of regional precipitation is associated with an increase in austral summer insolation over the Holocene. A significant deviation from mean-state changes is observed in the Late Holocene when monsoon intensity decreases, tropical sea surface temperatures increase, and paleoclimatic records indicate a shift to El Niño-like conditions. A stalagmite collected from Pacupahuain Cave grew over a 35,000-year interval (16,000–50,000 years ago) during the Last Glacial period. Abrupt millennial-scale events demonstrate that the SASM is sensitive to high latitude temperature changes in both hemispheres. The dating-precision of speleothem samples provides constraints on the timing of abrupt events in the high North and South Atlantic. Future work includes development of additional stalagmite samples that span distinct intervals of time over the last 275,000 years.

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Yes / Climate change and urbanization can increase pressures on groundwater resources, but little is known about how groundwater quality will change. Here, we rely on a global synthesis (n = 9,404) to reveal the drivers of dissolved organic carbon (DOC), which is an important component of water chemistry and substrate for microorganisms which control many biogeochemical reactions. Groundwater ions, local climate and land use explained ~ 31% of observed variability in groundwater DOC, whilst aquifer age explained an additional 16%. We identify a 19% increase in DOC associated with urban land cover. We predict major groundwater DOC increases following changes in precipitation and temperature in key areas relying on groundwater. Climate change and conversion of natural or agricultural areas to urban areas will decrease groundwater quality and increase water treatment costs, compounding existing threats to groundwater resources.