A model intercomparison of changes in the Atlantic thermohaline circulation in response to increasing atmospheric CO2 concentration

As part of the Coupled Model Intercomparison Project, integrations with a common design have been undertaken with eleven different climate models to compare the response of the Atlantic thermohaline circulation ( THC) to time-dependent climate change caused by increasing atmospheric CO2 concentration. Over 140 years, during which the CO2 concentration quadruples, the circulation strength declines gradually in all models, by between 10 and 50%. No model shows a rapid or complete collapse, despite the fairly rapid increase and high final concentration of CO2. The models having the strongest overturning in the control climate tend to show the largest THC reductions. In all models, the THC weakening is caused more by changes in surface heat flux than by changes in surface water flux. No model shows a cooling anywhere, because the greenhouse warming is dominant.

Soil quality response to land-use change for sugarcane expansion in Brazil

Globally, increasing demands for biofuels have intensified the rate of land-use change (LUC) for expansion of bioenergy crops. In Brazil, the world\'s largest sugarcane-ethanol producer, sugarcane area has expanded by 35% (3.2 Mha) in the last decade. Sugarcane expansion has resulted in extensive pastures being subjected to intensive mechanization and large inputs of agrochemicals, which have direct implications on soil quality (SQ). We hypothesized that LUC to support sugarcane expansion leads to overall SQ degradation. To test this hypothesis we conducted a field-study at three sites in the central-southern region, to assess the SQ response to the primary LUC sequence (i.e., native vegetation to pasture to sugarcane) associated to sugarcane expansion in Brazil. At each land use site undisturbed and disturbed soil samples were collected from the 0-10, 10-20 and 20-30 cm depths. Soil chemical and physical attributes were measured through on-farm and laboratory analyses. A dataset of soil biological attributes was also included in this study. Initially, the LUC effects on each individual soil indicator were quantified. Afterward, the LUC effects on overall SQ were assessed using the Soil Management Assessment Framework (SMAF). Furthermore, six SQ indexes (SQI) were developed using approaches with increasing complexity. Our results showed that long-term conversion from native vegetation to extensive pasture led to soil acidification, significant depletion of soil organic carbon (SOC) and macronutrients [especially phosphorus (P)] and severe soil compaction, which creates an unbalanced ratio between water- and air-filled pore space within the soil and increases mechanical resistance to root growth. Conversion from pasture to sugarcane improved soil chemical quality by correcting for acidity and increasing macronutrient levels. Despite those improvements, most of the P added by fertilizer accumulated in less plant-available P forms, confirming the key role of organic P has in providing available P to plants in Brazilian soils. Long-term sugarcane production subsequently led to further SOC depletions. Sugarcane production had slight negative impacts on soil physical attributes compared to pasture land. Although tillage performed for sugarcane planting and replanting alleviates soil compaction, our data suggested that the effects are short-term with persistent, reoccurring soil consolidation that increases erosion risk over time. These soil physical changes, induced by LUC, were detected by quantitative soil physical properties as well as by visual evaluation of soil structure (VESS), an on-farm and user-friendly method for evaluating SQ. The SMAF efficiently detected overall SQ response to LUC and it could be reliably used under Brazilian soil conditions. Furthermore, since all of the SQI values developed in this study were able to rank SQ among land uses. We recommend that simpler and more cost-effective SQI strategies using a small number of carefully chosen soil indicators, such as: pH, P, K, VESS and SOC, and proportional weighting within of each soil sectors (chemical, physical and biological) be used as a protocol for SQ assessments in Brazilian sugarcane areas. The SMAF and SQI scores suggested that long-term conversion from native vegetation to extensive pasture depleted overall SQ, driven by decreases in chemical, physical and biological indicators. In contrast, conversion from pasture to sugarcane had no negative impacts on overall SQ, mainly because chemical improvements offset negative impacts on biological and physical indicators. Therefore, our findings can be used as scientific base by farmers, extension agents and public policy makers to adopt and develop management strategies that sustain and/or improving SQ and the sustainability of sugarcane production in Brazil.

Pathways to Low Carbon Transport in the EU – From Possibility to Reality. Report of the CEPS Task Force on transport and climate change. CEPS Task Force Report, June 2013

A new CEPS Task Force Report has identified possible pathways for achieving the EU’s ambitious climate change targets. It concludes that a GHG emissions reduction in line with EU climate change policy is possible, but it requires immediate action. This report argues that most of the reductions required of the transport sector in the EU could come from more energy-efficient vehicles, combined with the gradual introduction of low-carbon fuels and new engine technologies. The key policy for reducing GHG emissions in road transport is the steady tightening of emissions standards in line with technological progress. The report also identifies strategies for the transport system to become more energy and/or carbon efficient, arguing that leverage can be further enhanced by local and city governments’ incentives for efficient and low-carbon vehicles in line with local circumstances and choices. The Task Force on Low Carbon Transport brought together a diverse set of stakeholders from the car and oil industries, business associations, international organisations, member states, academic experts and NGOs. This authoritative report is the result of that unique collaboration.

A European response to the resource and climate challenge. CHALLENGE EUROPE Issue 22 - Challenges and new beginnings: Priorities for the EU's new leadership, September 2014

The 20th Century was characterised by growth: the world population grew by four times and its economic output grew by 40 times. At the same time, the resource use and greenhouse gas emissions increased drastically. Only within the last two decades, the worldwide extraction of resources increased by over 50%. With the expectation that the demand of resources will triple by 2050 and the demand for food, feed and fibre is projected to increase by 70%, there is no doubt that we will exceed our planet's boundaries, the safe thresholds within which humanity can continue to develop and thrive for generations to come. Crossing these boundaries could generate abrubt or irreversible environmental changes. Respecting them reduces the risk that human society and ecosystems will face irreversible damages.

Fair Access to Energy Resources, Market Transfers and Climate Change in the WTO

This paper addresses the issues of dual pricing and export restrictions in the energy sector, stressing the comparability of their economic and climate change impacts. It assesses whether WTO disciplines relevant and applicable to such practices are well-equipped to ensure fair access to energy resources. It finds that relevant GATT disciplines are overall deficient in the case of dual pricing and export taxes, while the landscape of WTO-plus obligations generally consisting of a network of narrowly tailored commitments. It discusses possible avenues to address such practices under the ASCM to the extent that they distort domestic energy prices and subsidize consumption of cheap fossil fuels

Calcareous plankton response to orbital and millennial-scale climate changes from ODP Leg 161-975

The paleoenvironmental conditions through MIS 15-9 at the Mediterranean Ocean Drilling Program (ODP) Site 975 were interpreted by high resolution study of calcareous plankton assemblages compared with available d18O and d13C records and high resolution paleoclimate proxies from the Atlantic Ocean. Sea Surface Temperatures (SSTs) have been estimated from planktonic foraminiferal assemblages using the artificial neural networks method. Calcareous plankton varied dominantly on a glacial-interglacial scale as testified by the SST record, foraminiferal diversity, total coccolith abundance and changes in warm-water calcareous nannofossil taxa. A general increase in foraminiferal diversity and of total coccolith abundance is observed during interglacials. Warmest SSTs are reached during MIS 11, while MIS 12 and MIS 10 represent the coldest intervals of the studied record. During MIS 12, one of the most extreme glacials of the last million years, occurrence of Globorotalia inflata and of neogloboquadrinids indicates a shoaling of the interface between Atlantic inflowing and Mediterranean outflowing waters. Among calcareous nannofossils the distribution of Gephyrocapsa margereli-G. muellerae > 4 µm also supports a reduced Atlantic-Mediterranean exchange during MIS 12. Superimposed on glacial-interglacial variability, six short-terms coolings are recognized during MIS 12 and 10, which appear comparable in their distribution and amplitude to the Heinrich - type events documented in the Atlantic Ocean in the same interval. During these H-type events, N. pachyderma (s) and G. margereli-G. muellerae > 4 µm increase as a response to the enhanced inflow of cold Atlantic water into the Mediterranean via the Strait of Gibraltar. Mediterranean surface water hydrography appears to have been most severely affected at Termination V during the H-type event Ht4, possibly as a response to a large volume of Atlantic meltwater inflow via the Strait of Gibraltar and/or to freshwater/terrigenous input deriving from local mountain glaciers. Three additional SST coolings are recorded through MIS 14-16, but these are not well correlated with Heinrich - type events documented in the Atlantic Ocean in the same interval; during these cooling episodes only the subpolar Turborotalita quinqueloba increases. These results highlight the sensitive response of the Mediterranean basin to millennial-scale climate variations related to Northern Hemisphere ice-sheet instability and support the hypothesis that the tight connection between high latitude climate dynamics and Mediterranean sea surface water features can be traced through the Middle Pleistocene.

Processes for identifying regional influences of and responses to increasing atmospheric CO2 and climate change : the MINK project /

"TR052A-H."

Resolution of inquiry requesting the President of the United States to provide to the House of Representatives certain documents in his possession relating to the anticipated effects of climate change on the coastal regions of the United States : adverse report, together with minority views (to accompany H. Res. 515).

"November 15, 2005."

Department of Energy : proposed budget in support of the President's Climate Change Technology Initiative : report to the Chairman, Committee on the Budget, House of Representatives /

"B-279612"--P. 1.

Simulation and public communication of ocean response to changing sea ice concentration

Senior thesis written for Oceanography 445

Threatening Messages in Climate Change Communication

Thesis (Ph.D.)--University of Washington, 2016-06

Mapping the consequences of an unanticipated drug supply change of uncertain origins: Response to the commentaries

No Abstract