Half of the world's wetlands were lost last century. Logging and conversion have shrunk the world's forests by as much as half. Some 9 percent of the world's tree species are at risk of extinction; tropical deforestation may exceedsquare kilometers per year.
Basins with a significant groundwater component may be less responsive to climate change than indicated here. Consequences and Likelihoods of Changes Courtesy of NOAA Reservoir systems have multiple objectives, including irrigation, municipal and industrial use, hydropower production, flood control, and preservation of habitat for aquatic species.
These reduced flows will require more tradeoffs among objectives of the whole system of reservoirs, 32 especially with the added challenges of summer increases in electric power demand for cooling 33 and additional water consumption by crops and forests.
However, over-allocation of existing water supply, conflicting objectives, limited management flexibility caused by rigid water allocation and operating rules, and other institutional barriers to changing operations continue to limit progress towards adaptation in many parts of the Columbia River basin.
In highly managed rivers, release of deeper, colder water from reservoirs could offer one of the few direct strategies to lower water temperatures downstream. Some species may be able to change behavior or take advantage of cold-water refuges. Coastal Vulnerabilities In the coastal zone, the effects of sea level rise, erosion, inundation, threats to infrastructure and habitat, and increasing ocean acidity collectively pose a major threat to the region.
The authors and several dozen collaborators undertook a risk evaluation of the impacts of climate change in the Northwest that informed the development of the four key messages in this chapter see also Ch.
The qualitative comparative risk assessment underlying the key messages in the Northwest chapter was informed by the Northwest Regional Climate Risk Framing workshop December 2,in Portland, OR. The workshop brought together stakeholders and scientistsfrom a cross-section of sectors and jurisdictions within the region to discuss and rank the likelihood and consequences for key climate risks facing the Northwest region and previously identified in the Oregon Climate Change Adaptation Framework.
These included careful review of the foundational technical input report 13 and approximately 80 additional technical inputs provided to the NCA by the public, as well additional published literature.
They also drew heavily from two state climate assessment reports. The key regionally consequential risks thus identified are those deriving from projected changes in streamflow timing in particular, warming-related impacts in watersheds where snowmelt is an important contributor to flow ; coastal consequences of the combined impact of sea level rise and other climate-related drivers; and changes in Northwest forest ecosystems.
The Northwest chapter therefore focuses on the implications of these risks for Northwest water resources, key aquatic species, coastal systems, and forest ecosystems, as well as climate impacts on the regionally important, climate-sensitive agricultural sector.
These syntheses were followed by expert deliberation of draft key messages by the authors wherein each key message was defended before the entire author team before this key message was selected for inclusion in the report.
Evidence for observed global eustatic sea level rise and regional sea level change derives from satellite altimetry and coastal tide gauges. Evidence for projected global sea level rise is described in Ch. West Coast, and Parris et al.
Evidence for erosion and inundation associated with projected sea level rise is based on observations and mapping of coastal elevations and geospatial analyses of the extent and location of inundation associated with various sea level rise and storm surge scenarios. Vulnerability of coastal transportation infrastructure to climate change has been assessed by combining geospatial risk analyses with expert judgment of asset sensitivity to climate risk and criticality to the transportation system in Washington State and by assessing transportation infrastructure exposure to climate risks associated with sea level rise and river flooding in the region as a whole.
Evidence for impacts of climate change on coastal habitat is based on: Evidence for historical increases in ocean acidification is from observations of changes in coastal ocean conditions, which also indicate high spatial and temporal variability.
Evidence for marine species responses to climate change derives from observations of shifts in marine plankton, fish, and seabird species associated with historical changes in ocean conditions, including temperature and availability of preferred foods. Evidence for low adaptive capacity is from observations of extent of degraded or fragmented coastal habitat, existence of few options for mitigating changes in marine chemical properties, observed extent of barriers to inland habitat migration, narrow coastal transportation corridors, and limited transportation alternatives for rural coastal towns.
However, there is virtually no uncertainty in the direction sign of global sea level rise. There is also a solid understanding of the primary contributing factors and mechanisms causing sea level rise.
Other details concerning uncertainty in global sea level rise are treated elsewhere for example, NRC 53 and in Ch. Regional uncertainty in projected Northwest sea level rise results primarily from global factors such as ice sheet mass balance and local vertical land movement affecting relative sea level rise.
An accurate determination of vertical land deformation requires a sufficient density of monitoring sites for example, NOAA tide gauges and permanent GPS sites that monitor deformation to capture variations in land deformation over short spatial scales, and in many Northwest coastal locations such dense networks do not exist.
There is a general trend, however, of observed uplift along the northwestern portion of the Olympic Peninsula and of subsidence within the Puget Sound region GPS data gathered from PBO data sets -- http: There is also considerable uncertainty about potential impacts of climate change on processes that influence storminess and affect coastal erosion in the Northwest.
These uncertainties relate to system complexity and the limited number of studies and lack of consensus on future atmospheric and oceanic conditions that will drive changes in regional wind fields.An Atlantic Ocean circulation system that warms Europe's climate is weaker today than it has been in 1, years, say scientists.
Climate change sensitivity and exposure differ between bioclimatic zones and forest types in Europe. The study thus analysed climate change impacts separately for different bioclimatic regions/forest types.
The human impact on natural ecosystems has reached dangerous levels, even significantly altering the Earth's basic chemical cycles, says a new report, World Resources People and Ecosystems, The Fraying Web of Life.
The report paints a dismal picture of over-fished oceans, over-pumping of water for farming, destruction of coral reefs and forests, even too much tourism, with human. The effects of global warming are the environmental and social changes caused (directly or indirectly) by human emissions of greenhouse schwenkreis.com is a scientific consensus that climate change is occurring, and that human activities are the primary driver.
Many impacts of climate change have already been observed, including glacier retreat, changes in the timing of seasonal events (e.g. February All countries in the world face challenges in dealing with environmental problems stemming from climate change.
China's challenges in adapting to climate change are particularly acute as it is a country struggling to prevent even more pollution and natural disasters that stem, in part, from 30 years of unchecked economic growth.
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