Next decade critical to keep warming below 2°C or 1.5°C • The UNFCCC climate talks in June 2014 a... more Next decade critical to keep warming below 2°C or 1.5°C • The UNFCCC climate talks in June 2014 are aimed at increasing emissions reduction actions in the pre-2020 period, as well as substantially improving mitigation ambition for the post 2020 period in the new climate agreement to be concluded next year. • In order to prevent dangerous climate change and limit warming to below 2°C or 1.5°C, both Annex I and Non-Annex I countries need to both significantly increase the level of current action to reduce emissions ahead of 2020 and commit to deeper cuts in emissions than currently pledged post 2020. • In this update the Climate Action Tracker has conducted a new analysis of the IPCC AR5 emissions database to evaluate the required level of global and regional action for 2020, 2025 and 2030 to limit warming to below 2°C or 1.5°C with a likely (66%) and high (85%) probability. A likely pathway for limiting warming below 2°C still has a one in three chance of exceeding this level, and po...
National action on climate change mitigation appears to be joining the international climate nego... more National action on climate change mitigation appears to be joining the international climate negotiations in the new and ever popular "climate shuffle" dance. It involves maximum effort and motion while staying in the same spot…or even, in some cases, going backwards.
National action on climate change mitigation appears to be joining the international climate nego... more National action on climate change mitigation appears to be joining the international climate negotiations in the new and ever popular "climate shuffle" dance. It involves maximum effort and motion while staying in the same spot…or even, in some cases, going backwards. Recent emissions trends and estimates of the effects of those policies in place and proposed lead to a new estimate that warming is likely to approach 4°C by 2100, significantly above the warming that would result from full implementation of the pledges (3.3°C). The continuous global fossil-fuel intensive development of the past decade suggests that high warming levels of 4°C are more plausible than assuming full implementation of current pledges. Evidence is ever increasing that existing and planned policies are not sufficient for countries to meet these pledges. Emissions on the rise…
Gaining understanding of food-web processes often requires a simplified representation of natural... more Gaining understanding of food-web processes often requires a simplified representation of natural diversity. One such simplification can be based on functional traits, as functionally similar species may provide a similar contribution to ecosystem level-processes. However, understanding how similarity in functional traits actually translates into similar contributions to ecosystem-level properties remains a challenge due to the complex ways in which traits can influence species' dynamics. Moreover, in many communities, seasonality alters the abiotic and biotic forcing regime, causing ongoing changes to patterns of species' dominance; groups of species do not stay intact but are rather continuously subjected to changes throughout the year. Using long-term high frequency measurements of phytoplankton in Lake Constance, we investigated the effect of seasonal changes on the relationship between functional similarity and temporal dynamics similarity of 36 morphotypes, and the relative contribution of different functional traits during the different parts of the year. Our results revealed seasonal differences in the overall degree of synchronization of morphotypes' temporal dynamics and how combinations of functional traits influence the relationship between functional trait similarity and temporal dynamics similarity, showing that different forcing regimes change how species cope with their environment based on their functional traits. Moreover, we show that the individual functional traits matter at different periods of the year indicating that species which are dynamically similar at certain parts of the year may not be at others. The differential strength of the overall and individual impact of functional traits on species' temporal dynamics makes the cohesion of a pair of functionally similar species dependent on the different forcing. Hence, simplifying food webs based solely on functional traits may not provide consistent estimates of functional groups over all seasons.
1. Improving the mechanistic basis of biodiversity-ecosystem function relationships requires a be... more 1. Improving the mechanistic basis of biodiversity-ecosystem function relationships requires a better understanding of how functional traits drive the dynamics of populations. For example, environmental disturbances or grazing may increase synchronization of functionally similar species, whereas functionally different species may show independent dynamics, because of different responses to the environment. Competition for resources, on the other hand, may yield a wide range of dynamic patterns among competitors and lead functionally similar and different species to display synchronized to compensatory dynamics. The mixed effect of these forces will influence the temporal fluctuations of populations and, thus, the variability of aggregate community properties. 2. To search for a relationship between functional and dynamics similarity, we studied the relationship between functional trait similarity and temporal dynamics similarity for 36 morphotypes of phytoplankton using long-term high-frequency measurements. 3. Our results show that functionally similar morphotypes exhibit dynamics that are more synchronized than those of functionally dissimilar ones. Functionally dissimilar morphotypes predominantly display independent temporal dynamics. This pattern is especially strong when short time-scales are considered. 4. Negative correlations are present among both functionally similar and dissimilar phytoplankton morphotypes, but are rarer and weaker than positive ones over all temporal scales. 5. Synthesis. We demonstrate that diversity in functional traits decreases community variability and ecosystem-level properties by decoupling the dynamics of individual morphotypes.
National action on climate change mitigation appears to be joining the international climate nego... more National action on climate change mitigation appears to be joining the international climate negotiations in the new and ever popular "climate shuffle" dance. It involves maximum effort and motion while staying in the same spot…or even, in some cases, going backwards. Recent emissions trends and estimates of the effects of those policies in place and proposed lead to a new estimate that warming is likely to approach 4°C by 2100, significantly above the warming that would result from full implementation of the pledges (3.3°C). The continuous global fossil-fuel intensive development of the past decade suggests that high warming levels of 4°C are more plausible than assuming full implementation of current pledges. Evidence is ever increasing that existing and planned policies are not sufficient for countries to meet these pledges. Emissions on the rise…
With currently implemented government policies, greenhouse gas emissions are projected to lead to... more With currently implemented government policies, greenhouse gas emissions are projected to lead to a warming of 3.7˚C, about 0.6˚C higher than that under the Copenhagen pledges. Under present policies there is about a one in three chance of exceeding 4˚C by 2100. • Since the Warsaw COP began, the announcement by Japan effectively enlarged the 2020 emissions gap by 3-4% or 356 MtCO 2 e in 2020. Australia's backtracking on implementation could widen the gap by another 25 MtCO 2 e. These negative developments tend to outweigh some positive signals: the US could -if policies were fully implemented -reduce the gap by around 523 MtCO 2 e; and policy developments in China, including the ban on new coal-fired power plants in some regions, could deliver additional reductions in the near future. • Instead of developing domestic policies to meet ambitious international reduction pledges, recent policy development in some countries point to a weakening of action, widening the 2020 emissions ...
Next decade critical to keep warming below 2°C or 1.5°C • The UNFCCC climate talks in June 2014 a... more Next decade critical to keep warming below 2°C or 1.5°C • The UNFCCC climate talks in June 2014 are aimed at increasing emissions reduction actions in the pre-2020 period, as well as substantially improving mitigation ambition for the post 2020 period in the new climate agreement to be concluded next year. • In order to prevent dangerous climate change and limit warming to below 2°C or 1.5°C, both Annex I and Non-Annex I countries need to both significantly increase the level of current action to reduce emissions ahead of 2020 and commit to deeper cuts in emissions than currently pledged post 2020. • In this update the Climate Action Tracker has conducted a new analysis of the IPCC AR5 emissions database to evaluate the required level of global and regional action for 2020, 2025 and 2030 to limit warming to below 2°C or 1.5°C with a likely (66%) and high (85%) probability. A likely pathway for limiting warming below 2°C still has a one in three chance of exceeding this level, and po...
National action on climate change mitigation appears to be joining the international climate nego... more National action on climate change mitigation appears to be joining the international climate negotiations in the new and ever popular "climate shuffle" dance. It involves maximum effort and motion while staying in the same spot…or even, in some cases, going backwards.
National action on climate change mitigation appears to be joining the international climate nego... more National action on climate change mitigation appears to be joining the international climate negotiations in the new and ever popular "climate shuffle" dance. It involves maximum effort and motion while staying in the same spot…or even, in some cases, going backwards. Recent emissions trends and estimates of the effects of those policies in place and proposed lead to a new estimate that warming is likely to approach 4°C by 2100, significantly above the warming that would result from full implementation of the pledges (3.3°C). The continuous global fossil-fuel intensive development of the past decade suggests that high warming levels of 4°C are more plausible than assuming full implementation of current pledges. Evidence is ever increasing that existing and planned policies are not sufficient for countries to meet these pledges. Emissions on the rise…
Gaining understanding of food-web processes often requires a simplified representation of natural... more Gaining understanding of food-web processes often requires a simplified representation of natural diversity. One such simplification can be based on functional traits, as functionally similar species may provide a similar contribution to ecosystem level-processes. However, understanding how similarity in functional traits actually translates into similar contributions to ecosystem-level properties remains a challenge due to the complex ways in which traits can influence species' dynamics. Moreover, in many communities, seasonality alters the abiotic and biotic forcing regime, causing ongoing changes to patterns of species' dominance; groups of species do not stay intact but are rather continuously subjected to changes throughout the year. Using long-term high frequency measurements of phytoplankton in Lake Constance, we investigated the effect of seasonal changes on the relationship between functional similarity and temporal dynamics similarity of 36 morphotypes, and the relative contribution of different functional traits during the different parts of the year. Our results revealed seasonal differences in the overall degree of synchronization of morphotypes' temporal dynamics and how combinations of functional traits influence the relationship between functional trait similarity and temporal dynamics similarity, showing that different forcing regimes change how species cope with their environment based on their functional traits. Moreover, we show that the individual functional traits matter at different periods of the year indicating that species which are dynamically similar at certain parts of the year may not be at others. The differential strength of the overall and individual impact of functional traits on species' temporal dynamics makes the cohesion of a pair of functionally similar species dependent on the different forcing. Hence, simplifying food webs based solely on functional traits may not provide consistent estimates of functional groups over all seasons.
1. Improving the mechanistic basis of biodiversity-ecosystem function relationships requires a be... more 1. Improving the mechanistic basis of biodiversity-ecosystem function relationships requires a better understanding of how functional traits drive the dynamics of populations. For example, environmental disturbances or grazing may increase synchronization of functionally similar species, whereas functionally different species may show independent dynamics, because of different responses to the environment. Competition for resources, on the other hand, may yield a wide range of dynamic patterns among competitors and lead functionally similar and different species to display synchronized to compensatory dynamics. The mixed effect of these forces will influence the temporal fluctuations of populations and, thus, the variability of aggregate community properties. 2. To search for a relationship between functional and dynamics similarity, we studied the relationship between functional trait similarity and temporal dynamics similarity for 36 morphotypes of phytoplankton using long-term high-frequency measurements. 3. Our results show that functionally similar morphotypes exhibit dynamics that are more synchronized than those of functionally dissimilar ones. Functionally dissimilar morphotypes predominantly display independent temporal dynamics. This pattern is especially strong when short time-scales are considered. 4. Negative correlations are present among both functionally similar and dissimilar phytoplankton morphotypes, but are rarer and weaker than positive ones over all temporal scales. 5. Synthesis. We demonstrate that diversity in functional traits decreases community variability and ecosystem-level properties by decoupling the dynamics of individual morphotypes.
National action on climate change mitigation appears to be joining the international climate nego... more National action on climate change mitigation appears to be joining the international climate negotiations in the new and ever popular "climate shuffle" dance. It involves maximum effort and motion while staying in the same spot…or even, in some cases, going backwards. Recent emissions trends and estimates of the effects of those policies in place and proposed lead to a new estimate that warming is likely to approach 4°C by 2100, significantly above the warming that would result from full implementation of the pledges (3.3°C). The continuous global fossil-fuel intensive development of the past decade suggests that high warming levels of 4°C are more plausible than assuming full implementation of current pledges. Evidence is ever increasing that existing and planned policies are not sufficient for countries to meet these pledges. Emissions on the rise…
With currently implemented government policies, greenhouse gas emissions are projected to lead to... more With currently implemented government policies, greenhouse gas emissions are projected to lead to a warming of 3.7˚C, about 0.6˚C higher than that under the Copenhagen pledges. Under present policies there is about a one in three chance of exceeding 4˚C by 2100. • Since the Warsaw COP began, the announcement by Japan effectively enlarged the 2020 emissions gap by 3-4% or 356 MtCO 2 e in 2020. Australia's backtracking on implementation could widen the gap by another 25 MtCO 2 e. These negative developments tend to outweigh some positive signals: the US could -if policies were fully implemented -reduce the gap by around 523 MtCO 2 e; and policy developments in China, including the ban on new coal-fired power plants in some regions, could deliver additional reductions in the near future. • Instead of developing domestic policies to meet ambitious international reduction pledges, recent policy development in some countries point to a weakening of action, widening the 2020 emissions ...
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Papers by Marcia Rocha