3 resultados para assessment change

em Publishing Network for Geoscientific


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1. With the global increase in CO2 emissions, there is a pressing need for studies aimed at understanding the effects of ocean acidification on marine ecosystems. Several studies have reported that exposure to CO2 impairs chemosensory responses of juvenile coral reef fishes to predators. Moreover, one recent study pointed to impaired responses of reef fish to auditory cues that indicate risky locations. These studies suggest that altered behaviour following exposure to elevated CO2 is caused by a systemic effect at the neural level. 2. The goal of our experiment was to test whether juvenile damselfish Pomacentrus amboinensis exposed to different levels of CO2 would respond differently to a potential threat, the sight of a large novel coral reef fish, a spiny chromis, Acanthochromis polyancanthus, placed in a watertight bag. 3. Juvenile damselfish exposed to 440 (current day control), 550 or 700 µatm CO2 did not differ in their response to the chromis. However, fish exposed to 850 µatm showed reduced antipredator responses; they failed to show the same reduction in foraging, activity and area use in response to the chromis. Moreover, they moved closer to the chromis and lacked any bobbing behaviour typically displayed by juvenile damselfishes in threatening situations. 4. Our results are the first to suggest that response to visual cues of risk may be impaired by CO2 and provide strong evidence that the multi-sensory effects of CO2 may stem from systematic effects at the neural level.

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Probabilistic climate data have become available for the first time through the UK Climate Projections 2009, so that the risk of tree growth change can be quantified. We assess the drought risk spatially and temporally using drought probabilities and tree species vulnerabilities across Britain. We assessed the drought impact on the potential yield class of three major tree species (Picea sitchensis, Pinus sylvestris, and Quercus robur) which presently cover around 59% (400,700 ha) of state-managed forests, across lowland and upland sites. Here we show that drought impacts result mostly in reduced tree growth over the next 80 years when using b1, a1b and a1fi IPCC emissions scenarios. We found a maximum reduction of 94% but also a maximum increase of 56% in potential stand yield class in the 2080s from the baseline climate (1961-1990). Furthermore, potential production over the national forest estate for all three species in the 2080s may decrease due to drought by 42% in the lowlands and 32% in the uplands in comparison to the baseline climate. Our results reveal that potential tree growth and forest production on the national forest estate in Britain is likely to reduce, and indicate where and when adaptation measures are required. Moreover, this paper demonstrates the value of probabilistic climate projections for an important economic and environmental sector.

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This data set contains the inputs and the results of the REDD+ Policy Assessment Centre project (REDD-PAC) project (http://www.redd-pac.org), developed by a consortium of research institutes (IIASA, INPE, IPEA, UNEP-WCMC), supported by Germany's International Climate Initiative. Taking a new land use map of Brazil for 2000 as input, the research team used the global economic model GLOBIOM to project land use changes in Brazil up to 2050. Model projections show that Brazil has the potential to balance its goals of protecting the environment and becoming a major global producer of food and biofuels. The model results were taken into account by Brazilian decision-makers when developing the country's intended nationally determined contribution (INDC).