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Navigating trade-offs between dams and river conservation
- M.L. Thieme, D. Tickner, G. Grill, J.P. Carvallo, M. Goichot, J. Hartmann, J. Higgins, B. Lehner, M. Mulligan, C. Nilsson, K. Tockner, C. Zarfl, J. Opperman
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- Journal:
- Global Sustainability / Volume 4 / 2021
- Published online by Cambridge University Press:
- 10 August 2021, e17
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- Article
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Non-technical summary
There has been a long history of conflicts, studies, and debate over how to both protect rivers and develop them sustainably. With a pause in new developments caused by the global pandemic, anticipated further implementation of the Paris Agreement and high-level global climate and biodiversity meetings in 2021, now is an opportune moment to consider the current trajectory of development and policy options for reconciling dams with freshwater system health.
Technical summaryWe calculate potential loss of free-flowing rivers (FFRs) if proposed hydropower projects are built globally. Over 260,000 km of rivers, including Amazon, Congo, Irrawaddy, and Salween mainstem rivers, would lose free-flowing status if all dams were built. We propose a set of tested and proven solutions to navigate trade-offs associated with river conservation and dam development. These solution pathways are framed within the mitigation hierarchy and include (1) avoidance through either formal river protection or through exploration of alternative development options; (2) minimization of impacts through strategic or system-scale planning or re-regulation of downstream flows; (3) restoration of rivers through dam removal; and (4) mitigation of dam impacts through biodiversity offsets that include restoration and protection of FFRs. A series of examples illustrate how avoiding or reducing impacts on rivers is possible – particularly when implemented at a system scale – and can be achieved while maintaining or expanding benefits for climate resilience, water, food, and energy security.
Social media summaryPolicy solutions and development pathways exist to navigate trade-offs to meet climate resilience, water, food, and energy security goals while safeguarding FFRs.
6 - Hydropower within the climate, energy and water nexus
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- By Jeffrey J. Opperman, Chagrin Falls, Ohio, in the United States, Joerg Hartmann, Amherst, Massachusetts, David Harrison, Nature Conservancy's Global Water Program focusing on sustainable hydropower, based in Boulder, Colorado
- Edited by Jamie Pittock, Australian National University, Canberra, Karen Hussey, Australian National University, Canberra, Stephen Dovers, Australian National University, Canberra
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- Book:
- Climate, Energy and Water
- Published online:
- 05 April 2015
- Print publication:
- 19 March 2015, pp 79-107
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Summary
Introduction
Ensuring secure supplies of energy and water are among the great challenges that society confronts while seeking to maintain robust economies and raise billions of people out of poverty. The energy and water challenges are not independent, and the linkages between them are increasingly recognized. For example, the extraction and generation of energy can require enormous amounts of water while, similarly, the treatment and distribution of water can require considerable amounts of energy (Hussey and Pittock 2012; van Vliet et al. 2012). In the United States, the energy sector is the largest user (though not consumer) of water, while in California, for example, distributing water consumes nearly 20 per cent of the state's energy usage (California Energy Commission 2005).
Beyond these direct linkages – generating energy requires water, providing water requires energy – energy and water are intertwined in a variety of other ways. Hydropower is a form of energy where water itself acts as the ‘fuel’ for generation. Because nearly all hydropower is generated from dams on rivers, hydropower provides a very specific example of how water and energy interact. First, hydropower is a user of water that interacts with other users, such as urban water supply and irrigation. Second, the infrastructure required to generate hydropower – namely, dams and diversions – changes how rivers function. By altering river function, hydropower can affect a broad array of other resources, benefits and values produced by rivers. Third, other activities within a watershed can alter hydrologic processes, such as erosion, which can influence the performance and longevity of hydropower infrastructure (eg through reservoir sedimentation).
Climate is a third key factor, expanding the interaction between energy and water into a trio: the energy-water-climate nexus. Climate change will affect the water-energy nexus in a variety of ways. Most simply, climate change is forecast to alter both the supply and demand for water and energy (Kundzewicz et al. 2008; Ebinger and Vergara 2011), adding greater complexity and uncertainty to an already complex interaction and potentially adding increased stressors.
Signatures of adaptation to plant parasitism in nematode genomes
- DAVID McK. BIRD, JOHN T. JONES, CHARLES H. OPPERMAN, TAISEI KIKUCHI, ETIENNE G. J. DANCHIN
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- Journal:
- Parasitology / Volume 142 / Issue S1 / February 2015
- Published online by Cambridge University Press:
- 30 January 2014, pp. S71-S84
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Plant-parasitic nematodes cause considerable damage to global agriculture. The ability to parasitize plants is a derived character that appears to have independently emerged several times in the phylum Nematoda. Morphological convergence to feeding style has been observed, but whether this is emergent from molecular convergence is less obvious. To address this, we assess whether genomic signatures can be associated with plant parasitism by nematodes. In this review, we report genomic features and characteristics that appear to be common in plant-parasitic nematodes while absent or rare in animal parasites, predators or free-living species. Candidate horizontal acquisitions of parasitism genes have systematically been found in all plant-parasitic species investigated at the sequence level. Presence of peptides that mimic plant hormones also appears to be a trait of plant-parasitic species. Annotations of the few genomes of plant-parasitic nematodes available to date have revealed a set of apparently species-specific genes on every occasion. Effector genes, important for parasitism are frequently found among those species-specific genes, indicating poor overlap. Overall, nematodes appear to have developed convergent genomic solutions to adapt to plant parasitism.
Food shopping behaviours and exposure to discrimination
- Shannon N Zenk, Amy J Schulz, Barbara A Israel, Graciela Mentz, Patricia Y Miranda, Alisha Opperman, Angela M Odoms-Young
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- Journal:
- Public Health Nutrition / Volume 17 / Issue 5 / May 2014
- Published online by Cambridge University Press:
- 27 March 2013, pp. 1167-1176
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Objective
The present study examined food shopping behaviours, particularly distance to grocery shop, and exposure to discrimination.
DesignCross-sectional observational study utilizing data from a community survey, neighbourhood food environment observations and the decennial census.
SettingThree communities in Detroit, Michigan, USA.
SubjectsProbability sample of 919 African-American, Latino and white adults in 146 census blocks and sixty-nine census block groups.
ResultsOn average, respondents shopped for groceries 3·1 miles (4·99 km) from home, with 30·9 % shopping within 1 mile (1·61 km) and 22·3 % shopping more than 5 miles (8·05 km) from home. Longer distance to shop was associated with being younger, African-American (compared with Latino), a woman, higher socio-economic status, lower satisfaction with the neighbourhood food environment, and living in a neighbourhood with higher poverty, without a large grocery store and further from the nearest supermarket. African-Americans and those with the lowest incomes were particularly likely to report unfair treatment at food outlets. Each mile (1·61 km) increase in distance to shop was associated with a 7 % increase in the odds of unfair treatment; this relationship did not differ by race/ethnicity.
ConclusionsThe study suggests that unfair treatment in retail interactions warrants investigation as a pathway by which restricted neighbourhood food environments and food shopping behaviours may adversely affect health and contribute to health disparities. Efforts to promote ‘healthy’ and equitable food environments should emphasize local availability and affordability of a range of healthy food products, as well as fair treatment while shopping regardless of race/ethnicity or socio-economic status.