902 resultados para Intergovernmental Panel on Climate Change


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Climate projections indicate that rising temperatures will affect summer crops in the southern Iberian Peninsula. The aim of this study was to obtain projections of the impacts of rising temperatures, and of higher frequency of extreme events on irrigated maize, and to evaluate some adaptation strategies. The study was conducted at several locations in Andalusia using the CERES-Maize crop model, previously calibrated/validated with local experimental datasets. The simulated climate consisted of projections from regional climate models from the ENSEMBLES project; these were corrected for daily temperature and precipitation with regard to the E-OBS observational dataset. These bias-corrected projections were used with the CERES-Maize model to generate future impacts. Crop model results showed a decrease in maize yield by the end of the 21st century from 6 to 20%, a decrease of up to 25% in irrigation water requirements, and an increase in irrigation water productivity of up to 22%, due to earlier maturity dates and stomatal closure caused by CO2 increase. When adaptation strategies combining earlier sowing dates and cultivar changes were considered, impacts were compensated, and maize yield increased up to 14%, compared with the baseline period (1981-2010), with similar reductions in crop irrigation water requirements. Effects of extreme maximum temperatures rose to 40% at the end of the 21st century, compared with the baseline. Adaptation resulted in an overall reduction in extreme Tmax damages in all locations, with the exception of Granada, where losses were limited to 8%.

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Recent studies point to climate change being one of the long-term drivers of agricultural market uncertainty. To advance in the understanding of the influence of climate change on future agricultural market developments, we compare a reference scenario for 2030 with alternative simulation scenarios that differ regarding: (1) emission scenarios; (2) climate projections; and (3) the consideration of carbon fertilization effects. For each simulation scenario, the CAPRI model provides global and EU-wide impacts of climate change on agricultural markets. Results show that climate change would considerably affect agrifood markets up to 2030. Nevertheless, market-driven adaptation strategies (production intensification, trade adjustments) would soften the impact of yield shocks on supply and demand. As a result, regional changes in production would be lower than foreseen by other studies focused on supply effects.

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The relation between changes in modern glaciers, not including the ice sheets of Greenland and Antarctica, and their climatic environment is investigated to shed light on paleoglacier evidence of past climate change and for projecting the effects of future climate warming on cold regions of the world. Loss of glacier volume has been more or less continuous since the 19th century, but it is not a simple adjustment to the end of an “anomalous” Little Ice Age. We address the 1961–1997 period, which provides the most observational data on volume changes. These data show trends that are highly variable with time as well as within and between regions; trends in the Arctic are consistent with global averages but are quantitatively smaller. The averaged annual volume loss is 147 mm⋅yr−1 in water equivalent, totaling 3.7 × 103 km3 over 37 yr. The time series shows a shift during the mid-1970s, followed by more rapid loss of ice volume and further acceleration in the last decade; this is consistent with climatologic data. Perhaps most significant is an increase in annual accumulation along with an increase in melting; these produce a marked increase in the annual turnover or amplitude. The rise in air temperature suggested by the temperature sensitivities of glaciers in cold regions is somewhat greater than the global average temperature rise derived largely from low altitude gauges, and the warming is accelerating.

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The atmosphere displays modes of variability whose structures exhibit a strong longitudinally symmetric (annular) component that extends from the surface to the stratosphere in middle and high latitudes of both hemispheres. In the past 30 years, these modes have exhibited trends that seem larger than their natural background variability, and may be related to human influences on stratospheric ozone and/or atmospheric greenhouse gas concentrations. The pattern of climate trends during the past few decades is marked by rapid cooling and ozone depletion in the polar lower stratosphere of both hemispheres, coupled with an increasing strength of the wintertime westerly polar vortex and a poleward shift of the westerly wind belt at the earth's surface. Annular modes of variability are fundamentally a result of internal dynamical feedbacks within the climate system, and as such can show a large response to rather modest external forcing. The dynamics and thermodynamics of these modes are such that strong synergistic interactions between stratospheric ozone depletion and greenhouse warming are possible. These interactions may be responsible for the pronounced changes in tropospheric and stratospheric climate observed during the past few decades. If these trends continue, they could have important implications for the climate of the 21st century.

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Calendar date of the beginning of the growing season at high altitude in the Colorado Rocky Mountains is variable but has not changed significantly over the past 25 years. This result differs from growing evidence from low altitudes that climate change is resulting in a longer growing season, earlier migrations, and earlier reproduction in a variety of taxa. At our study site, the beginning of the growing season is controlled by melting of the previous winter's snowpack. Despite a trend for warmer spring temperatures the average date of snowmelt has not changed, perhaps because of the trend for increased winter precipitation. This disjunction between phenology at low and high altitudes may create problems for species, such as many birds, that migrate over altitudinal gradients. We present data indicating that this already may be true for American robins, which are arriving 14 days earlier than they did in 1981; the interval between arrival date and the first date of bare ground has grown by 18 days. We also report evidence for an effect of climate change on hibernation behavior; yellow-bellied marmots are emerging 38 days earlier than 23 years ago, apparently in response to warmer spring air temperatures. Migrants and hibernators may experience problems as a consequence of these changes in phenology, which may be exacerbated if climate models are correct in their predictions of increased winter snowfall in our study area. The trends we report for earlier formation of permanent snowpack and for a longer period of snow cover also have implications for hibernating species.

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Insect damage on fossil leaves from the Central Rocky Mountains, United States, documents the response of herbivores to changing regional climates and vegetation during the late Paleocene (humid, warm temperate to subtropical, predominantly deciduous), early Eocene (humid subtropical, mixed deciduous and evergreen), and middle Eocene (seasonally dry, subtropical, mixed deciduous and thick-leaved evergreen). During all three time periods, greater herbivory occurred on taxa considered to have short rather than long leaf life spans, consistent with studies in living forests that demonstrate the insect resistance of long-lived, thick leaves. Variance in herbivory frequency and diversity was highest during the middle Eocene, indicating the increased representation of two distinct herbivory syndromes: one for taxa with deciduous, palatable foliage, and the other for hosts with evergreen, thick-textured, small leaves characterized by elevated insect resistance. Leaf galling, which is negatively correlated with moisture today, apparently increased during the middle Eocene, whereas leaf mining decreased.

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The ocean's thermohaline circulation has long been recognized as potentially unstable and has consequently been invoked as a potential cause of abrupt climate change on all timescales of decades and longer. However, fundamental aspects of thermohaline circulation changes remain poorly understood.

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While the topic of climate change is controversial, the world needs to take a precautionary approach to reduce carbon dioxide emissions. With growing populations and increasing energy demands, solutions to cleaner energy need to be developed and implemented. In order to successfully reduce carbon dioxide emissions, a global carbon pricing policy needs to be developed that includes all countries and allows each region to utilize the best clean energy technology options along with economic incentives that will be the most effective. The research conducted in this project validates the hypothesis that placing a monetary price on carbon will allow natural, technological, and financial resources to come together to implement a feasible energy solution that will reduce global carbon dioxide emissions.

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Tese de doutoramento, Alterações Climáticas e Políticas de Desenvolvimento Sustentável (Sociologia), Universidade de Lisboa, Instituto de Ciências Sociais, 2016

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This special report is intended to serve as a background briefing document for the European Climate Platform seminar on Carbon Markets in the 2015 Agreement: Role and Architecture, but also raises issues of more enduring relevance in the wider debate about market mechanisms and the next climate change agreement. The paper looks at the relationship between the carbon market and a new climate change agreement, to be finalised in Paris in 2015. It tries to answer two key questions: does the carbon market have a role to play in a post-2020 agreement, and what is the role of a post-2020 agreement in the creation and operation of a carbon market? Introduction. The world has changed in many ways since 1997 when the Kyoto Protocol was adopted, along some critical axes, both from an economic and emissions points of view. Moreover, and this cannot be quantified, the appetite for global governance, especially for an agreement with such far-reaching implications as a climate change agreement, has diminished considerably. This paper looks at the relationship between the carbon market and a new climate change agreement, to be finalised in Paris in 2015. It tries to answer two key questions: does the carbon market have a role to play in a post-2020 agreement, and what is the role of a post-2020 agreement in the creation and operation of a carbon market?

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In surveying the portfolio for climate change assigned to Commissioner-designate Arias Cañete, Andrei Marcu finds in this CEPS Commentary that the approach proposed in the European Commission’s January 2014 package offers a sound basis on which to proceed overall, but he specifies that it needs to be put in a context where the causes and symptoms are correctly identified. He singles out timing and governance as other important elements and discusses their practical implications.

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This policy paper focuses on the sustainable management of some key natural resources in southern and eastern Mediterranean countries (SEMCs) under climate change and anthropogenic pressures. In a business-as-usual and even more so in a failed cooperation scenario, water resources, ecosystems and biodiversity in the region are under stress, with negative consequences for agriculture, food security, tourism and development. However, proper adaptation strategies are shown to be effective in reconciling resource conservation with GDP, trade and population growth. These need be implemented in different ways: technological, institutional, behavioural; and at different levels: regional, national and international. There is ample room for fruitful cooperation between the EU and SEMCs in this area, which can take the form of EU direct financial and technical support when resources in SEMCs are scarce, and of multilateral and bilateral cooperation programmes to improve resource efficiency. The EU could also take on the role of coordinating these different bilateral actions and, at the same time, support SEMCs to establish a structured programme focused on the communication and dissemination of emerging best practices.

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Reducing the psychological distance of climate change has repeatedly been proposed as one strategy to increase individuals' motivation to respond to climate change. From the perspective of construal level theory, decreasing psychological distance should not itself influence people's willingness to act but change the processes that underlie individual decision-making. We conducted two experiments in which we manipulated the psychological distance of climate change. We found that participants with a distant focus relied more on scepticism to represent risks and make decisions about supporting climate change, whereas participants with a proximal perspective relied more on fear when making such judgements. However, the predicted Fear × Distance interaction was only found when self-reported fear rather than experimentally manipulated fear was used as a moderator. Our results suggest that simply proximising won't increase engagement and call for a more differentiated perspective on the effects of psychological distance in the context of climate change.

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This paper examines how local communities adapt to climate change and how governance structures can foster or undermine adaptive capacity. Climate change policies, in general, and disaster risk management in mountain regions, in particular, are characterised by their multi-level and multi-sectoral nature during formulation and implementation. The involvement of numerous state and non-state actors at local to national levels produces a variety of networks of interaction and communication. The paper argues that the structure of these relational patterns is critical for understanding adaptive capacity. It thus proposes an expanded concept of adaptive capacity that incorporates (horizontal and vertical) actor integration and communication flow between these actors. The paper further advocates the use of formal social network analysis to assess these relational patterns. Preliminary results from research on adaptation to climate change in a Swiss mountain region vulnerable to floods and other natural hazards illustrate the conceptual and empirical significance of the main arguments.

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Change Adaptation: Open or Closed? Paper read at the Second African International Economic Law Network Conference, 7-8 March 2013, Wits School of Law, Johannesburg, South Africa. In a time of rapid convergence of technologies, goods, services, hardware, software, the traditional classifications that informed past treaties fail to remove legal uncertainty, or advance welfare and innovation. As a result, we turn our attention to the role and needs of the public domain at the interface of existing intellectual property rights and new modes of creation, production and distribution of goods and services. The concept of open culture would have it that knowledge should be spread freely and its growth should come from further developing existing works on the basis of sharing and collaboration without the shackles of intellectual property. Intellectual property clauses find their way into regional, multilateral, bilateral and free trade agreements more often than not, and can cause public discontent and incite unrest. Many of these intellectual property clauses raise the bar on protection beyond the clauses found in the WTO Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS). In this paper we address the question of the protection and development of the public domain in service of open innovation in accord with Article 15 of the International Covenant on Economic, Social and Cultural Rights (ICESCR) in light of the Objectives (Article 7) and Principles (Article 8) set forth in TRIPS. Once areas of divergence and reinforcement between the intellectual property regime and human rights have been discussed, we will enter into options that allow for innovation and prosperity in the global south. We then conclude by discussing possible policy developments.