Contribution of Changes in Atmospheric Circulation Patterns to Extreme Temperature Trends

Nature Portfolio (Springer Nature) | July 24th, 2015

Surface weather conditions are closely governed by the large-scale circulation of the Earth’s atmosphere. Recent increases in the occurrence of some extreme wea

Surface weather conditions are closely governed by the large-scale circulation of the Earth’s atmosphere. Recent increases in the occurrence of some extreme weather phenomena have led to multiple mechanistic hypotheses linking changes in atmospheric circulation to increasing probability of extreme events. However, observed evidence of long-term change in atmospheric circulation remains inconclusive. Here we identify statistically significant trends in the occurrence of atmospheric circulation patterns, which partially explain observed trends in surface temperature extremes over seven mid-latitude regions of the Northern Hemisphere. Using self-organizing map cluster analysis, we detect robust circulation pattern trends in a subset of these regions during both the satellite observation era (1979–2013) and the recent period of rapid Arctic sea-ice decline (1990–2013). Particularly substantial influences include the contribution of increasing trends in anticyclonic circulations to summer and autumn hot extremes over portions of Eurasia and North America, and the contribution of increasing trends in northerly flow to winter cold extremes over central Asia. Our results indicate that although a substantial portion of the observed change in extreme temperature occurrence has resulted from regional- and global-scale thermodynamic changes, the risk of extreme temperatures over some regions has also been altered by recent changes in the frequency, persistence and maximum duration of regional circulation patterns.

Contribution of historical precipitation change to US flood damages

Publisher not available | January 26th, 2021

Precipitation extremes have increased across many regions of the United States, with further increases anticipated in response to additional global warming. Quantifying

Precipitation extremes have increased across many regions of the United States, with further increases anticipated in response to additional global warming. Quantifying the impact of these precipitation changes on flood damages is necessary to estimate the costs of climate change. However, there is little empirical evidence linking changes in precipitation to the historically observed increase in flood losses. We use >6,600 reports of state-level flood damage to quantify the historical relationship between precipitation and flood damages in the United States. Our results show a significant, positive effect of both monthly and 5-d state-level precipitation on state-level flood damages. In addition, we find that historical precipitation changes have contributed approximately one-third of cumulative flood damages over 1988 to 2017 (primary estimate 36%; 95% CI 20 to 46%), with the cumulative impact of precipitation change totaling $73 billion (95% CI 39 to $91 billion). Further, climate models show that anthropogenic climate forcing has increased the probability of exceeding precipitation thresholds at the extremely wet quantiles that are responsible for most flood damages. Climate models project continued intensification of wet conditions over the next three decades, although a trajectory consistent with UN Paris Agreement goals significantly curbs that intensification. Taken together, our results quantify the contribution of precipitation trends to recent increases in flood damages, advance estimates of the costs associated with historical greenhouse gas emissions, and provide further evidence that lower levels of future warming are very likely to reduce financial losses relative to the current global warming trajectory.

Contribution of the Pacific Decadal Oscillation to global mean sea level trend

American Geophysical Union (AGU) | October 3rd, 2013

Understanding and explaining the trend in global mean sea level (GMSL) have important implications for future projections of sea level rise. While measurements from sa

Understanding and explaining the trend in global mean sea level (GMSL) have important implications for future projections of sea level rise. While measurements from satellite altimetry have provided accurate estimates of GMSL, the modern altimetry record has only now reached 20 years in length, making it difficult to assess the contribution of decadal to multi-decadal climate signals to the global trend. Here, we use a sea level reconstruction to study the 20 year trends in sea level since 1950. In particular, we show that the Pacific Decadal Oscillation (PDO) contributes significantly to the 20 year trends in GMSL. We estimate the PDO contri-bution to the GMSL trend over the past 20 years to beapproximately 0.49 ± 0.25 mm/year and find that removing the PDO contribution reduces the acceleration in GMSL estimated over the past 60 years. 

Contributions of Climate Change and ENSO Variability to Future Precipitation Extremes Over California

American Geophysical Union (AGU) | June 14th, 2023

Contributions of recycled wastewater to clean water and sanitation Sustainable Development Goals

Clean Water | April 30th, 2020

Water resources are essential for every development activity, not only in terms of available quantity but also in terms of quality. Population growth and urbani

Water resources are essential for every development activity, not only in terms of available quantity but also in terms of quality. Population growth and urbanisation are increasing the number of users and uses of water, making water resources scarcer and more polluted. Changes in rainfall patterns threaten to worsen these effects in many areas. Water scarcity, due to physical lack or pollution, has become one of the most pressing issues globally, a matter of human, economic and environmental insecurity. Wastewater, whose value had not been appreciated until recently, is increasingly recognised as a potential ‘new’ source of clean water for potable and non-potable uses, resulting in social, environmental and economic benefits. This paper discusses the potential of recycled wastewater (also known as reused water) to become a significant source of safe water for drinking purposes and improved sanitation in support of the Sustainable Development Goals.

Control of the Clear Lake Gnat in California

Entomological Society of America (ESA) | August 1st, 1951

Conveyance - Delta (Resource Management Strategy)

California Department of Water Resources (DWR) | July 29th, 2016

The Sacramento-San Joaquin Delta (Delta) is the confluence point of the Sacramento and San Joaquin rivers as water is naturally conveyed westward from upstream water basi

The Sacramento-San Joaquin Delta (Delta) is the confluence point of the Sacramento and San Joaquin rivers as water is naturally conveyed westward from upstream water basins to the bays connected to the Pacific Ocean (Figure 1). In its natural state, the Delta was a vast marsh and floodplain dissected by meandering channels and sloughs. Even in today’s highly altered environment, the Delta remains a critical ecosystem and dynamic habitat that is home to hundreds of aquatic and terrestrial species, including many species endemic to the area and a number that are designated as threatened or endangered by the federal Endangered Species Act (ESA) and California Endangered Species Act (CESA). The Delta is also a centerpiece of California’s water system. The conveyance of water through the Delta supplies water for more than 25 million Californians. The water conveyed through the Delta also supports farms and ranches stretching from the north Delta to California-Mexico border, which collectively produce nearly half of the nation’s domestically grown fresh produce and supports a $27 billion agricultural industry. In addition to being a key agricultural region itself and recreational destination, the Delta supports extensive infrastructure of statewide importance, such as aqueducts, natural gas pipelines, electricity transmission lines, railroads, shipping channels, and highways.

Conveyance — Regional/Local (Resource Management Strategy)

California Department of Water Resources (DWR) | July 29th, 2016

Conveyance provides for the movement of water, geographically connecting the supply to the demand. Conveyance infrastructure includes natural watercourses as well as huma

Conveyance provides for the movement of water, geographically connecting the supply to the demand. Conveyance infrastructure includes natural watercourses as well as human-made facilities like canals, pipelines, and flood bypasses. Examples of natural watercourses include streams, rivers, floodplains, and groundwater aquifers. Conveyance facilities range in size from small, local, end-user distribution systems to the large systems that move water to and from distant areas. Conveyance facilities also require associated infrastructure such as pumping plants, diversion structures, fish ladders, and fish screens. Regional and local water supply conveyance is discussed in this resource management strategy report.

Coordinated Long-Term Operation of the Central Valley Project and State Water Project, Final Environmental Impact Statement

U.S. Bureau of Reclamation (USBR) | November 30th, 2015

Corning Subbasin Groundwater Sustainability Plan

Tehama County Flood Control and Water Conservation District | December 20th, 2021

Preparation of this GSP is the first step for the GSAs to achieve groundwater sustainability in the Corning Subbasin. To evaluate progress toward groundwater sustainabili

Preparation of this GSP is the first step for the GSAs to achieve groundwater sustainability in the Corning Subbasin. To evaluate progress toward groundwater sustainability during implementation, annual reports and 5-year updates to the GSP will be prepared as required by SGMA. The GSAs recognize that sustainability is only possible with support of stakeholders and coordination of local, state, tribal and federal agencies and the managed use of both surface and groundwater resources. While SGMA does not require the Plan to address California’s Public Trust Doctrine, a 2018 California Court of Appeal ruling found that groundwater pumping that reduces the flow or volume of water in a navigable stream (and tributaries that supply navigable streams) may violate the public trust. This Plan recognizes the importance of protecting public trust resources, including fish and wildlife, in the Subbasin’s streams that are connected to groundwater.