446 research outputs found
Climate change on a live Earth
Els líders mundials consideren que les conclusions
del Grup Intergovernamental d'Experts sobre el Canvi Climàtic
(GIECC) són fiables; tant és així que les prediccions obtingudes
s'utilitzen per a formular lleis i polítiques. No obstant això, el
GIECC no ha sobreestimat el canvi climàtic, sinó que ha subestimat
la gravetat de l'escalfament global, principalment perquè
ha prestat massa atenció a les emissions de diòxid de carboni
i no la suficient a la resposta de la Terra. Al llarg dels últims
quaranta-quatre anys he treballat observant la Terra d'una manera
diferent, com un sistema dinàmic que regula activament el
clima i la composició atmosfèrica per mantenir el planeta habitable.
La Terra no accepta passivament l'acció humana. Respon
al canvi climàtic d'una manera molt més mortífera que el
petit canvi que estem provocant. La teoria de Gaia sosté que el
sistema Terra pot actuar com un amplificador i les petites modificacions,
ja siguin cap a la calor o al fred, s'intensifiquen, fet
que podria ser la causa dels canvis erràtics de temperatura. En
aquest article intentaré demostrar que aturar el canvi climàtic
pot ser més difícil del que creuen els governs. La nostra tasca,
en cas que l'escalfament global continuï, és adaptar-nos a la
nova situació i preparar-nos per a sobreviure.The findings of the Intergovernmental Panel on Climate
Change (IPCC) are taken by world leaders as authoritative,
so much so that their predictions are used to frame legislation
and policy. However, the IPCC has not overestimated
climate change, they have, instead, underestimated the severity
of global heating mainly because they paid too much attention
to our emissions of carbon dioxide and not enough to the
Earths response. For the past 44 years I have worked on a different
way of looking at the Earth, seeing it as a dynamic system
that actively regulates the climate and the atmospheric
composition to keep the planet habitable. The Earth does not
passively accept what we do to it. It responds to climate
change and that response is far more deadly than the small
change that we are making. Gaia theory teaches that the Earth
system can act as an amplifier and small changes either to heat
or cold are intensified and this could be the cause of the erratic
shifts of temperature. In this article I will try to show that stopping
climate change may be more difficult than our governments
believe. Our task, should global heating continue, is to
adapt and prepare to survive
Modeled CO2 Emissions from Coastal Wetland Transitions to Other Land Uses: Tidal Marshes, Mangrove Forests, and Seagrass Beds
The sediments of coastal wetlands contain large stores of carbon which are vulnerable to oxidation once disturbed, resulting in high levels of CO2 emissions that may be avoided if coastal ecosystems are conserved or restored. We used a simple model to estimate CO2 emissions from mangrove forests, seagrass beds, and tidal marshes based on known decomposition rates for organic matter in these ecosystems under either oxic or anoxic conditions combined with assumptions of the proportion of sediment carbon being deposited in either oxic or anoxic environments following a disturbance of the habitat. Our model found that over 40 years after disturbance the cumulative CO2 emitted from tidal marshes, mangrove forests, and seagrass beds were ∼70–80% of the initial carbon stocks in the top meter of the sediment. Comparison of our estimates of CO2 emissions with empirical studies suggests that (1) assuming 50% of organic material moves to an oxic environment after disturbance gives rise to estimates that are similar to CO2 emissions reported for tidal marshes; (2) field measurements of CO2 emissions in disturbed mangrove forests were generally higher than our modeled emissions that assumed 50% of organic matter was deposited in oxic conditions, suggesting higher proportions of organic matter may be exposed to oxic conditions after disturbance in mangrove ecosystems; and (3) the generally low observed rates of CO2 emissions from disturbed seagrasses compared to our estimates, assuming removal of 50% of the organic matter to oxic environments, suggests that lower proportions may be exposed to oxic conditions in seagrass ecosystems. There are significant gaps in our knowledge of the fate of wetland sediment carbon in the marine environment after disturbance. Greater knowledge of the distribution, form, decomposition, and emission rates of wetland sediment carbon after disturbance would help to improve models
'What About Love?': claiming and re-claiming LGBTQ+ spaces in 21st century musical theatre
This is an accepted manuscript of a book chapter published by Red Globe Press in Reframing the Musical: Race, Culture and Identity, edited by Sarah Whitfield, available online: https://www.macmillanihe.com/page/detail/Reframing-the-Musical/?K=9781352004397
The accepted version of the publication may differ from the final published version
Daisyworld: a review
Daisyworld is a simple planetary model designed to show the long-term effects of coupling between life and its environment. Its original form was introduced by James Lovelock as a defense against criticism that his Gaia theory of the Earth as a self-regulating homeostatic system requires teleological control rather than being an emergent property. The central premise, that living organisms can have major effects on the climate system, is no longer controversial. The Daisyworld model has attracted considerable interest from the scientific community and has now established itself as a model independent of, but still related to, the Gaia theory. Used widely as both a teaching tool and as a basis for more complex studies of feedback systems, it has also become an important paradigm for the understanding of the role of biotic components when modeling the Earth system. This paper collects the accumulated knowledge from the study of Daisyworld and provides the reader with a concise account of its important properties. We emphasize the increasing amount of exact analytic work on Daisyworld and are able to bring together and summarize these results from different systems for the first time. We conclude by suggesting what a more general model of life-environment interaction should be based on
‘Not just for gays anymore’: men, masculinities and musical theatre
This thesis explores how the changing masculinities of the
21 century have affected how young men connect to musical theatre as a genre that has been stereotypically seen as gay. The investigation is first located in the theoretical framework of masculinities, utilising the concepts of the male sex role, hegemonic masculinities and inclusive masculinity to chart how the performance of the male gender has changed over the past century. The project then adopts an empirical approach to a group of 161 men and 25 women, establishing a methodological framework for correlating sexual orientation with attitudes towards musical theatre. There is a further honing of this methodology through the adoption of Jenifer Toksvig's exercise, which identifies how each participant connects to narrative through a core emotional drive. Finally, this data is tested through three case studies of how individual participants connect to , and , concluding that the emotional content of musical theatre is now as desirable to straight men as it is to women and LGBT men
Rolling covenants to protect coastal ecosystems in the face of sea-level rise
This article considers how “rolling covenants” (i.e., covenants on land title that can operate in a “rolling” geographic area to keep pace with sea-level rise) can be used to permit productive use of land in the short term, while ensuring land use can shift over time to allow for coastal ecosystem migration in the medium to long term. We use Australia as a case study, and through analysis of legislation and a series of semistructured interviews, we demonstrate how land title-based covenants can be used to give legal effect to “rolling covenant” arrangements where land is subject to existing use and occupation. We then consider practical issues associated with drafting a rolling covenant arrangement, including an analysis of the types of events or scenarios that could be used as a basis for land use changing (e.g., projected sea-level rise, actual ecosystem migration), and the advantages and disadvantages of each. We conclude that rolling covenants are a viable option for land management in the coastal zone, especially in circumstances where funding sources are available to incentivize uptake. Rolling covenants may provide opportunities for coastal wetlands to be maintained and even enhanced in cover, thereby delivering important ecosystem services (e.g., blue carbon) into the future
Thermal stability of dialkylimidazolium tetrafluoroborate and hexafluorophosphate ionic liquids: ex situ bulk heating to complement in situ mass spectrometry
Thermal decomposition (TD) products of the ionic liquids (ILs) [CnC1Im][BF4] and [CnC1Im][PF6] ([CnC1Im]+ = 1-alkyl-3-methylimidazolium, [BF4]- = tetrafluoroborate, and [PF6]- = hexafluorophosphate) were prepared, ex situ, by bulk heating experiments in a bespoke setup. The respective products, CnC1(C3N2H2)BF3 and CnC1(C3N2H2)PF5 (1-alkyl-3-methylimidazolium-2-trifluoroborate and 1-alkyl-3-methylimidazolium-2-pentafluorophosphate), were then vaporized and analyzed by direct insertion mass spectrometry (DIMS) in order to identify their characteristic MS signals. During IL DIMS experiments we were subsequently able, in situ, to identify and monitor signals due to both IL vaporization and IL thermal decomposition. These decomposition products have not been observed in situ during previous analytical vaporization studies of similar ILs. The ex situ preparation of TD products is therefore perfectly complimentary to in situ thermal stability measurements. Experimental parameters such as sample surface area to volume ratios and heating rates are consequently very important for ILs that show competitive vaporization and thermal decomposition. We have explained these experimental factors in terms of Langmuir evaporation and Knudsen effusion-like conditions, allowing us to draw together observations from previous studies to make sense of the literature on IL thermal stability. Hence, the design of experimental setups are crucial and previously overlooked experimental factors
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The effects of elevated CO2 and eutrophication on surface elevation gain in a European salt marsh.
Salt marshes can play a vital role in mitigating the effects of global environmental change by dissipating incident storm wave energy and, through accretion, tracking increasing water depths consequent upon sea level rise. Atmospheric CO2 concentrations and nutrient availability are two key variables that can affect the biological processes that contribute to marsh surface elevation gain. We measured the effects of CO2 concentrations and nutrient availability on surface elevation change in intact mixed-species blocks of UK salt marsh using six open-top chambers receiving CO2 -enriched (800 ppm) or ambient (400 ppm) air. We found more rapid surface elevation gain in elevated CO2 conditions: an average increase of 3.4 mm over the growing season relative to ambient CO2 . Boosted regression analysis to determine the relative influence of different parameters on elevation change identified that a 10% reduction in microbial activity in elevated CO2 -grown blocks had a positive influence on elevation. The biomass of Puccinellia maritima also had a positive influence on elevation, while other salt marsh species (e.g. Suaeda maritima) had no influence or a negative impact on elevation. Reduced rates of water use by the vegetation in the high CO2 treatment could be contributing to elevation gain, either directly through reduced soil shrinkage or indirectly by decreasing microbial respiration rates due to lower redox levels in the soil. Eutrophication did not influence elevation change in either CO2 treatment despite doubling aboveground biomass. The role of belowground processes (transpiration, root growth and decomposition) in the vertical adjustment of European salt marshes, which are primarily minerogenic in composition, could increase as atmospheric CO2 concentrations rise and should be considered in future wetland models for the region. Elevated CO2 conditions could enhance resilience in vulnerable systems such as those with low mineral sediment supply or where migration upwards within the tidal frame is constrained.Marie Curie Incoming International Fellowship (Grant ID: FP7-PEOPLE-IIF 623720 STORM)This is the author accepted manuscript. The final version is available from Wiley via https://doi.org/10.1111/gcb.1339
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