The challenge of closing the climate adaptation gap for water supply utilities

Nature Portfolio (Springer Nature) | June 29th, 2024

The challenge of hot drought

Nature Portfolio (Springer Nature) | November 21st, 2013

Drought is heating up around the warming world. Particularly hot drought has cost more than US$40 billion and claimed 218 human lives since 2010 in the United States alon

Drought is heating up around the warming world. Particularly hot drought has cost more than US$40 billion and claimed 218 human lives since 2010 in the United States alone. These hot and dry conditions have also contributed to unusually widespread and devastating wildfires, fuelled by wide expanses of weakened and dead trees that were unable to deal with heat stress and subsequent insect attack. Yet, to get a real sense of how this recent change in drought severity might shape the future, one has to look to the past. An analysis of regional and pan-continental North American drought over the past 1,000 years, reported by Cook et al in the Journal of Climate, makes it clear that recent droughts, as costly as they have been, are only a taste of what might lie ahead, independently of any big climate change.

The challenge of unprecedented floods and droughts in risk management

Nature Portfolio (Springer Nature) | August 3rd, 2022

Risk management has reduced vulnerability to floods and droughts globally, yet their impacts are still increasing. An improved understanding of the causes of changing imp

Risk management has reduced vulnerability to floods and droughts globally, yet their impacts are still increasing. An improved understanding of the causes of changing impacts is therefore needed, but has been hampered by a lack of empirical data. On the basis of a global dataset of 45 pairs of events that occurred within the same area, we show that risk management generally reduces the impacts of floods and droughts but faces difficulties in reducing the impacts of unprecedented events of a magnitude not previously experienced. If the second event was much more hazardous than the first, its impact was almost always higher. This is because management was not designed to deal with such extreme events: for example, they exceeded the design levels of levees and reservoirs. In two success stories, the impact of the second, more hazardous, event was lower, as a result of improved risk management governance and high investment in integrated management. The observed difficulty of managing unprecedented events is alarming, given that more extreme hydrological events are projected owing to climate change.

The Climate has Changed: Now what? Integrated Regional Water Management and Climate Change Planning A Coincidental or Inevitable Union?

California Department of Water Resources (DWR) | March 27th, 2012

Adapting California’s water management systems in response to climate   change presents one of the most significant challenges for the 21st century. In the course of

Adapting California’s water management systems in response to climate   change presents one of the most significant challenges for the 21st century. In the course of the past five years, the California Department of Water Resources has taken an active role in both identifying opportunities to mitigate greenhouse gas (GHG) emissions and in positioning California to adapt to changes happening now and in the future. The recent publication of the Climate Change Handbook for Regional Water Planning is the most recent effort to bring together two separate water planning efforts – integrated regional water management and climate change mitigation and adaptation. The key to this planning synthesis is a significant change in the way water planners have addressed issues of water management. This paper looks at the development of integrated regional water management and climate change planning by the CDWR and their current union in the Handbook.

The Coming Megafloods

Scientific American | May 5th, 2013

Huge flows of vapor in the atmosphere, dubbed “atmospheric rivers,” have unleashed massive floods every 200 years, and climate change could bring more of them.

Huge flows of vapor in the atmosphere, dubbed “atmospheric rivers,” have unleashed massive floods every 200 years, and climate change could bring more of them.

The critical role of humidity in modeling summer electricity demand across the United States

Nature Portfolio (Springer Nature) | April 3rd, 2020

Cooling demand is projected to increase under climate change. However, most of the existing projections are based on rising air temperatures alone, ignoring that

Cooling demand is projected to increase under climate change. However, most of the existing projections are based on rising air temperatures alone, ignoring that rising temperatures are associated with increased humidity; a lethal combination that could significantly increase morbidity and mortality rates during extreme heat events. We bridge this gap by identifying the key measures of heat stress, considering both air temperature and near-surface humidity, in characterizing the climate sensitivity of electricity demand at a national scale. Here we show that in many of the high energy consuming states, such as California and Texas, projections based on air temperature alone underestimates cooling demand by as much as 10–15% under both present and future climate scenarios. Our results establish that air temperature is a necessary but not sufficient variable for adequately characterizing the climate sensitivity of cooling load, and that near-surface humidity plays an equally important role.

The demographic decline of a sea lion population followed multi‐decadal sea surface warming

Nature Portfolio (Springer Nature) | June 26th, 2020

The population growth of top predators depends largely on environmental conditions suitable for aggregating sufficient and high‐quality prey. We reconstructe

The population growth of top predators depends largely on environmental conditions suitable for aggregating sufficient and high‐quality prey. We reconstructed numerically the size of a resident population of California sea lions in the Gulf of California during 1978–2019 and its relation with multi‐decadal sea surface temperature anomalies. This is the first multi‐decadal examination of the sea surface temperature of the Gulf of California and of one of its major predators. A three‐decade sustained warming explained the population’s trend accounting for 92% of the variance, including a 65% decline between 1991 and 2019. Long‐term warming conditions started in the late 80s, followed by the population’s decline from 43,834 animals (range 34,080–58,274) in 1991 to only 15,291 (range 11,861–20,316) in 2019. The models suggested a century‐scale optimum sea surface habitat occurring in mildly temperate waters, from 0.18 to 0.39 °C above the 100‐year mean. The mechanistic links of this relation are still untested, but apparent diversification of pelagic fish catches suggests a reduction of high quality prey. We propose this population should be considered vulnerable to any disturbance that could add to the negative effects of the current warm sea surface conditions in the Gulf of California.

The disappearing Salton Sea: A critical reflection on the emerging environmental threat of disappearing saline lakes and potential impacts on children's health

Science of the Total Environment (Elsevier) | February 6th, 2019

Changing weather patterns, droughts and competing water demands are dramatically altering the landscape and creating conditions conducive to the production of wind-blown

Changing weather patterns, droughts and competing water demands are dramatically altering the landscape and creating conditions conducive to the production of wind-blown dust and dust storms. In California, such factors are leading to the rapid shrinking of the Salton Sea, a 345 mile2 land-locked “sea” situated near the southeastern rural border region known as the Imperial Valley. The region is anticipated to experience a dramatic increase in wind-blown dust and existing studies suggest a significant impact on the health and quality of life for nearby residents of this predominantly low-income, Mexican-American community. The discussion calls attention to the public health dimensions of the Salton Sea crisis. We know little about the possible long-term health effects of exposure to mobilized lakebed sediments or the numerous toxic contaminants that may become respirable on entrained particles. We draw on existing epidemiological literature of other known sources of wind-blown dust, such as desert dust storms, and related health effects to begin to understand the potential public health impact of wind-blown dust exposure. The increased production of wind-blown dust and environmental exposures to such non-combustion related sources of particulate matter are a growing health threat, due in part to drought coupled with increasing pressures on limited water resources. Recent population-based studies have linked dust storms with cardiovascular mortality, asthma hospitalization and decrease in pulmonary function in both adults and children. A growing number of studies provide evidence of the acute health effects of wind-blown dust exposures among children, which with repeated insults have the potential to influence respiratory health over time. The shrinking of the Salton Sea illustrates a public health and environmental justice crisis that requires action and attention to protect the health and well-being of local communities.

The drivers and the implications of marine heatwaves

National Academy of Sciences (NAS) | June 24th, 2022

The effect of the El Niño-Southern Oscillation on U.S. regional and coastal sea level

American Geophysical Union (AGU) | June 3rd, 2015

Although much of the focus on future sea level rise concerns the long-term trend associated with anthropogenic warming, on shorter time scales, internal climate variabil

Although much of the focus on future sea level rise concerns the long-term trend associated with anthropogenic warming, on shorter time scales, internal climate variability can contribute significantly to regional sea level. Such sea level variability should be taken into consideration when planning efforts to mitigate the effects of future sea level change. In this study, we quantify the contribution to regional sealevel of the El Niño-Southern Oscillation (ENSO). Through cyclostationary empirical orthogonal function analysis (CSEOF) of the long reconstructed sea level data set and of a set of U.S. tide gauges, two global modes dominated by Pacific Ocean variability are identified and related to ENSO and, by extension, the Pacific Decadal Oscillation. By estimating the combined contribution of these two modes to regional sealevel, we find that ENSO can contribute significantly on short time scales, with contributions of up to 20 cm along the west coast of the U.S. The CSEOF decomposition of the long tide gauge records around the U.S. highlights the influence of ENSO on the U.S. east coast. Tandem analyses of both the reconstructed and tidegauge records also examine the utility of the sea level reconstructions for near-coast studies.