title: Changes to population-based emergence of climate change from CMIP5 to CMIP6

authors: Douglas, Hunter C.

abstract: Abstract The Coupled Model Intercomparison Project Phase 6 (CMIP6) model ensemble projects climate change emerging soonest and most strongly at low latitudes, regardless of the emissions pathway taken. In terms of signal-to-noise (S/N) ratios of average annual temperatures, these models project earlier and stronger emergence under the Shared Socio-economic Pathways than the previous generation did under corresponding Representative Concentration Pathways. Spatial patterns of emergence also change between generations of models; under a high emissions scenario, mid-century S/N is lower than previous studies indicated in Central Africa, South Asia, and parts of South America, West Africa, East Asia, and Western Europe, but higher in most other populated areas. We show that these global and regional changes are caused by a combination of higher effective climate sensitivity in the CMIP6 ensemble, as well as changes to emissions pathways, component-wise effective radiative forcing, and region-scale climate responses between model generations. We also present the first population-weighted calculation of climate change emergence for the CMIP6 ensemble, quantifying the number of people exposed to increasing degrees of abnormal temperatures now and into the future. Our results confirm the expected inequity of climate change-related impacts in the decades between now and the 2050 target for net-zero emissions held by many countries. These findings underscore the importance of concurrent investments in both mitigation and adaptation.

text: Changes to population-based emergence of climate change from CMIP5 to CMIP6 Abstract The Coupled Model Intercomparison Project Phase 6 (CMIP6) model ensemble projects climate change emerging soonest and most strongly at low latitudes, regardless of the emissions pathway taken. In terms of signal-to-noise (S/N) ratios of average annual temperatures, these models project earlier and stronger emergence under the Shared Socio-economic Pathways than the previous generation did under corresponding Representative Concentration Pathways. Spatial patterns of emergence also change between generations of models; under a high emissions scenario, mid-century S/N is lower than previous studies indicated in Central Africa, South Asia, and parts of South America, West Africa, East Asia, and Western Europe, but higher in most other populated areas. We show that these global and regional changes are caused by a combination of higher effective climate sensitivity in the CMIP6 ensemble, as well as changes to emissions pathways, component-wise effective radiative forcing, and region-scale climate responses between model generations. We also present the first population-weighted calculation of climate change emergence for the CMIP6 ensemble, quantifying the number of people exposed to increasing degrees of abnormal temperatures now and into the future. Our results confirm the expected inequity of climate change-related impacts in the decades between now and the 2050 target for net-zero emissions held by many countries. These findings underscore the importance of concurrent investments in both mitigation and adaptation.

year: 2023-01-01

title: Temperature and Moisture Sensitivity of Soil Microbial Respiration in Adjacent Irrigated and Non-Irrigated Soils

authors: Petrie, Olivia Jane

subjects: Soil Microbial Respiration

abstract: Irrigation is a commonly used management practice that is crucial for increasing plant growth and production, especially in areas prone to drought such as the Canterbury region of the South Island, New Zealand. Historically, irrigation was thought to increase soil carbon content due to increased production, however recent studies have shown that irrigation causes a loss of soil carbon (C). One possible mechanism for the C loss is an increase in soil microbial respiration under irrigation. The added soil moisture under irrigation releases microbial moisture limitations and enables soil microbes to access more C, therefore increasing respiration and decreasing soil C content. Soil microbial respiration also fluctuates seasonally. Irrigation changes the inherent seasonal effect by increasing soil moisture content during the hottest part of the year, therefore increasing soil microbial respiration rates.
In this thesis soil samples were collected from 13 paired irrigated and non-irrigated sites in Canterbury and two sites at Rangiriri in the Waikato region of the North Island. The sites in Canterbury were sampled once while the sites at Rangiriri were used for a seasonal analysis and were sampled twice. Soil samples were wet to five different moisture contents and incubated on a temperature gradient block for five hours. MMRT curves were then fitted to the respiration data obtained from incubation and the temperature optima (Topt), temperature inflection point (Tinf) and change in heat capacity (ΔCp‡) were calculated. The absolute respiration rates at 10°C (R10) and 20°C (R20) were also calculated. 
Irrigation had a significant effect on soil microbial respiration in the Canterbury soils but not the Rangiriri soils. In Canterbury, the Topt and Tinf were higher in the irrigated soils by 8.8°C and 7.6°C respectively while the R10 and R20 were both nearly 50% higher in the non-irrigated soils and all differences were statistically significant. There was no difference between treatments in any of the parameters measured in the Rangiriri soils. 
The difference in temperature sensitivity and absolute respiration rate in the Canterbury soils was thought to be due to the soil microbes under irrigation decomposing less readily available soil C which has a higher temperature sensitivity and leads to a reduced respiration rate. Another possible explanation for the differences in temperature sensitivity and absolute respiration rate was that there had been a shift in soil microbial community structure between the two treatments and this should be further investigated.

text: Temperature and Moisture Sensitivity of Soil Microbial Respiration in Adjacent Irrigated and Non-Irrigated Soils Irrigation is a commonly used management practice that is crucial for increasing plant growth and production, especially in areas prone to drought such as the Canterbury region of the South Island, New Zealand. Historically, irrigation was thought to increase soil carbon content due to increased production, however recent studies have shown that irrigation causes a loss of soil carbon (C). One possible mechanism for the C loss is an increase in soil microbial respiration under irrigation. The added soil moisture under irrigation releases microbial moisture limitations and enables soil microbes to access more C, therefore increasing respiration and decreasing soil C content. Soil microbial respiration also fluctuates seasonally. Irrigation changes the inherent seasonal effect by increasing soil moisture content during the hottest part of the year, therefore increasing soil microbial respiration rates.
In this thesis soil samples were collected from 13 paired irrigated and non-irrigated sites in Canterbury and two sites at Rangiriri in the Waikato region of the North Island. The sites in Canterbury were sampled once while the sites at Rangiriri were used for a seasonal analysis and were sampled twice. Soil samples were wet to five different moisture contents and incubated on a temperature gradient block for five hours. MMRT curves were then fitted to the respiration data obtained from incubation and the temperature optima (Topt), temperature inflection point (Tinf) and change in heat capacity (ΔCp‡) were calculated. The absolute respiration rates at 10°C (R10) and 20°C (R20) were also calculated. 
Irrigation had a significant effect on soil microbial respiration in the Canterbury soils but not the Rangiriri soils. In Canterbury, the Topt and Tinf were higher in the irrigated soils by 8.8°C and 7.6°C respectively while the R10 and R20 were both nearly 50% higher in the non-irrigated soils and all differences were statistically significant. There was no difference between treatments in any of the parameters measured in the Rangiriri soils. 
The difference in temperature sensitivity and absolute respiration rate in the Canterbury soils was thought to be due to the soil microbes under irrigation decomposing less readily available soil C which has a higher temperature sensitivity and leads to a reduced respiration rate. Another possible explanation for the differences in temperature sensitivity and absolute respiration rate was that there had been a shift in soil microbial community structure between the two treatments and this should be further investigated.

year: 2017

title: Site-specific performance rituals in the Anthropocene

authors: Claus, Johanna

abstract: In this creative practice PhD, I investigated site-specific performance rituals in the Anthropocene. Driven by the urge to respond to the challenges of the current time, I examined how different seasonal rituals might be expressed in specific sites in Aotearoa, New Zealand. Furthermore, including participants from diverse cultural backgrounds, and carrying an awareness of the complexities of colonialism, I analysed insights from key ritual experts to enhance my understanding of ritual practices within the specific socio-cultural and environmental context of Aotearoa. Inspired by critical posthumanist philosophies, I viewed ritual practices through a lens that considered the interconnectedness of technology, culture, and nature, moving beyond essentialist and dualistic tendencies. Inspired by (Haraway, 2007) and Braidotti (2019), I embraced a perspective of ‘staying with the trouble’ and ‘radical hope’ as a strategy to inspire commitments to safeguarding life on Earth amid increasing societal divisions, and environmental disasters.
Working at the intersection of various disciplines, I crafted a qualitative research design that embraced multiple ways of knowing through creative practice research. I gathered insights from four ritual experts grounded in mātauranga Māori or neo-Paganism through in-depth interviews, to comprehend multifaceted and culturally sensitive approaches to ritual practices in Aotearoa. Moreover, the creative investigation of four seasonal performance rituals served as the primary mode of inquiry (Niedderer & Roworth-Stokes, 2007; Skains, 2018). The methods used for these rituals included contemporary performance practices, eco-somatic movement, improvisation, site-specific dance, audience participation, and others.
The rich knowledge gained throughout these investigations is conveyed through the documentation of four seasonal rituals, presented in video works alongside this thesis. The findings are articulated in two empirical chapters, one focusing on the findings and analysis of the expert interviews and the other on the findings and analysis of four performance rituals, revealing nuanced and complex insights into the creation of site-specific performance rituals in the Anthropocene. Navigating site-specific performance practices as an immigrant necessitated continuous critical self-reflection on biases and assumptions, leading to intricate explorations of embodiment, identity, culture, nature, and the more-than-human world within a posthuman context. Operating in the liminal space of this tension alongside performer participants, ritual experts, and audience members yielded the articulation of my findings: a ritual score capable of accommodating the complexities of the Anthropocene.

text: Site-specific performance rituals in the Anthropocene In this creative practice PhD, I investigated site-specific performance rituals in the Anthropocene. Driven by the urge to respond to the challenges of the current time, I examined how different seasonal rituals might be expressed in specific sites in Aotearoa, New Zealand. Furthermore, including participants from diverse cultural backgrounds, and carrying an awareness of the complexities of colonialism, I analysed insights from key ritual experts to enhance my understanding of ritual practices within the specific socio-cultural and environmental context of Aotearoa. Inspired by critical posthumanist philosophies, I viewed ritual practices through a lens that considered the interconnectedness of technology, culture, and nature, moving beyond essentialist and dualistic tendencies. Inspired by (Haraway, 2007) and Braidotti (2019), I embraced a perspective of ‘staying with the trouble’ and ‘radical hope’ as a strategy to inspire commitments to safeguarding life on Earth amid increasing societal divisions, and environmental disasters.
Working at the intersection of various disciplines, I crafted a qualitative research design that embraced multiple ways of knowing through creative practice research. I gathered insights from four ritual experts grounded in mātauranga Māori or neo-Paganism through in-depth interviews, to comprehend multifaceted and culturally sensitive approaches to ritual practices in Aotearoa. Moreover, the creative investigation of four seasonal performance rituals served as the primary mode of inquiry (Niedderer & Roworth-Stokes, 2007; Skains, 2018). The methods used for these rituals included contemporary performance practices, eco-somatic movement, improvisation, site-specific dance, audience participation, and others.
The rich knowledge gained throughout these investigations is conveyed through the documentation of four seasonal rituals, presented in video works alongside this thesis. The findings are articulated in two empirical chapters, one focusing on the findings and analysis of the expert interviews and the other on the findings and analysis of four performance rituals, revealing nuanced and complex insights into the creation of site-specific performance rituals in the Anthropocene. Navigating site-specific performance practices as an immigrant necessitated continuous critical self-reflection on biases and assumptions, leading to intricate explorations of embodiment, identity, culture, nature, and the more-than-human world within a posthuman context. Operating in the liminal space of this tension alongside performer participants, ritual experts, and audience members yielded the articulation of my findings: a ritual score capable of accommodating the complexities of the Anthropocene.

year: 2024-05-27