Climate change
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As the old saying goes, politics makes strange bedfellows.  A national carbon tax to fund increased border security fits that description. President Trump's request for these funds is a major sticking point with Democrats in the current budget impasse. However, many of the younger generation of Democrats elected to the House in the midterm election strongly support government action to address the climate challenge. 

Is there a way for all sides to declare victory from this solution? Increased funding for border security would allow the president to fulfill a campaign promise that is extremely important to his base. A carbon tax would allow Democrats to score a major climate policy victory. A significant chunk of the revenues from the carbon tax could go to increase the safety of asylum-seekers and the speed at which their requests are processed. The remaining revenues could contribute to the deficit reduction goals of traditional Republicans. Finally, all three groups could claim credit for a reduced risk of global climate change and a more humanitarian approach to dealing with asylum-seekers.

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Commentary
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The Hill
Authors
Frank Wolak
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Progressive Democrats assert that the Green New Deal is the best way to reduce global greenhouse gas emissions.

But this claim ignores the fact that subsidizing “green” energy technologies, such as wind and solar, is less effective than taxing the greenhouse gas emissions produced by brown energy sources, such as oil, natural gas and coal.

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Commentary
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The Hill
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Frank Wolak
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Floods and other climate hazards pose a widespread and growing threat to housing and infrastructure around the world. By incorporating climate risk into asset prices, markets can discourage excessive development in hazardous areas. However, the extent to which markets actually price these risks remains poorly understood. Here we measure the effect of information about flood risk on residential property values in the United States. Using multiple empirical approaches and two decades of sales data covering the universe of homes in the US, we find little evidence that housing markets fully price information about flood risk in aggregate. However, the price penalty for flood risk is larger for commercial buyers and in states where sellers must disclose information about flood risk to potential buyers, suggesting that policies to improve risk communication could influence market outcomes. Our findings indicate that floodplain homes in the US are currently overvalued by a total of $34B, raising concerns about the stability of real estate markets as climate risks become more salient and severe.

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Working Papers
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The National Bureau of Economic Research
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Marshall Burke
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California has experienced devastating autumn wildfires in recent years. These autumn wildfires have coincided with extreme fire weather conditions during periods of strong offshore winds coincident with unusually dry vegetation enabled by anomalously warm conditions and late onset of autumn precipitation. In this study, we quantify observed changes in the occurrence and magnitude of meteorological factors that enable extreme autumn wildfires in California, and use climate model simulations to ascertain whether these changes are attributable to human-caused climate change. We show that state-wide increases in autumn temperature (~1 ˚C) and decreases in autumn precipitation (~30%) over the past four decades have contributed to increases in aggregate fire weather indices (+20%). As a result, the observed frequency of autumn days with extreme (95th percentile) fire weather – which we show are preferentially associated with extreme autumn wildfires – has more than doubled in California since the early 1980s. We further find an increase in the climate model-estimated probability of these extreme autumn conditions since ~1950, including a long-term trend toward increased same-season co-occurrence of extreme fire weather conditions in northern and southern California. Our climate model analyses suggest that continued climate change will further amplify the number of days with extreme fire weather by the end of this century, though a pathway consistent with the UN Paris commitments would substantially curb that increase. Given the acute societal impacts of extreme autumn wildfires in recent years, our findings have critical relevance for ongoing efforts to manage wildfire risks in California and other regions.

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Environmental Research Letters
Authors
Noah Diffenbaugh
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Independent verification of anthropogenic influence on specific extreme climate events remains elusive. This study presents a framework for such verification. This framework reveals that previously published results based on a 1961–2005 attribution period frequently underestimate the influence of global warming on the probability of unprecedented extremes during the 2006–2017 period. This underestimation is particularly pronounced for hot and wet events, with greater uncertainty for dry events. The underestimation is reflected in discrepancies between probabilities predicted during the attribution period and frequencies observed during the out-of-sample verification period. These discrepancies are most explained by increases in climate forcing between the attribution and verification periods, suggesting that 21st-century global warming has substantially increased the probability of unprecedented hot and wet events. Hence, the use of temporally lagged periods for attribution—and, more broadly, for extreme event probability quantification—can cause underestimation of historical impacts, and current and future risks.

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Science Advances
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Noah Diffenbaugh
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Researchers including David Lobell analyze how human-caused climate change has impacted a water deficit in Southern Africa and might contribute to a rising food security crisis in the region.

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Global Change Biology
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David Lobell
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Many international policy problems, including climate change, have been characterized as global public goods. We adopt this theoretical framework to identify the baseline determinants of individual opinion about climate policy. The model implies that support for climate action will be increasing in future benefits, their timing, and the probability that a given country's contribution will make a difference while decreasing in expected costs. Utilizing original surveys in France, Germany, the United Kingdom, and the United States, we provide evidence that expected benefits, costs, and the probability of successful provision as measured by the contribution of other nations are critical for explaining support for climate action. Notably, we find no evidence that the temporality of benefits shapes support for climate action. These results indicate that climate change may be better understood as a static rather than a dynamic public goods problem and suggest strategies for designing policies that facilitate climate cooperation.

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SSRN
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Authors
Callista Wells
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The Stanford Center at Peking University (SCPKU), the Center on Democracy, Development and the Rule of Law (CDDRL), and the APARC China Program jointly hosted a workshop on China’s Belt and Road Initiative (BRI) in early March. The workshop, held on March 2 and 3, welcomed researchers from around the world with expertise in the Initiative. Unfortunately, because of the rapidly developing health emergency related to the coronavirus, participants from not only China, but also Japan, were prevented from attending. As described by Professor Jean Oi, founding director of SCPKU and the China Program, and Professor Francis Fukuyama, director of CDDRL and the Ford Dorsey Master's in International Policy, who co-chaired the workshop, the meeting aimed to provide a global perspective on the BRI, consolidate knowledge on this opaque topic, and determine the best method and resources for future research.  

The workshop began with presentations from several of the invited guests. Dr. Atif Ansar from the University of Oxford’s Saïd Business School kicked off the first day by describing not only the tremendous opportunity that the BRI presents to developing economies, but also the serious pitfalls that often accompany colossal infrastructure projects. Pointing out the poor returns on investment of mega infrastructure projects, Ansar examined the frequest cost and schedule overruns, random disasters, and environmental degradation that outweigh the minimal benefits that they generally yield. China’s own track record from domestic infrastructure projects does little to mitigate fear of these risks, Ansar claimed. In response, he urged professional management of BRI investments, institutional reforms, and intensified deployment of technology in BRI projects. Dr. Ansar was followed by Dr. Xue Gong of the S. Rajaratnam School of International Studies, Nanyang Technological University, Singapore. Dr. Gong’s analysis centered on the extent to which China’s geopolitical motivations influenced its outward foreign direct investments (OFDI). Although her research was still in the early stages, her empirical analysis of China’s OFDI inflows into fifty BRI recipient countries from 2007-2018 nevertheless revealed that geopolitical factors often outweigh economic factors when it comes to China’s OFDI destinations.

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Amit Bhandari of Gateway House: Indian Council on Global Relations presents his research at the Belt and Road Workshop.
Participants then heard presentations from Amit Bhandari of Gateway House: Indian Council on Global Relations and Professor Cheng-Chwee Kuik of the National University of Malaysia. Mr. Bhandari’s talk focused on Chinese investments in India’s six neighboring countries, which tend to center more on energy rather than connectivity projects. He first found that the investments are generally not economical for the host countries because they come with high costs and high interest rates. Secondly, he argued that these projects often lacked a clear economic rationale, appearing instead to embed a geopolitical logic not always friendly to India. Professor Kuik, by contrast, provided a counterexample in his analysis of BRI projects in Southeast Asia. He described how, in Southeast Asia, host countries’ reception of the BRI has varied substantially; and how various stakeholders, including states, sub-states and other entities, have used their leverage to shape outcomes more or less favorable to themselves. Kuik’s analysis injected complexity into the often black-and-white characterizations of the BRI. He highlighted the multidimensional dynamics that play out among local and state-level players in pursuit of their goals, and in the process of BRI implementation.

Professor Curtis J. Milhaupt and Scholar-in-Residence Jeffrey Ball, both at Stanford Law School, followed with individual presentations on the role of State-Owned Enterprises (SOEs) in the BRI and the emissions impact of the BRI on climate change, respectively. Professor Milhaupt  characterized Chinese SOEs as both geopolitical and commercial actors, simultaneously charged with implementing Party policies and attaining corporate profits. Chinese SOEs are major undertakers of significant overseas BRI projects, acting not only as builders but also as investors, partners, and operators. This situation, Milhaupt asserted, carries significant risks for SOEs because these megaprojects often provide dismal returns, have high default rates, and can trigger political backlash in their localities. Milhaupt highlighted the importance of gathering firm-level data on businesses actually engaged in BRI projects to better infer geostrategic, financial, or other motivations. Jeffrey Ball turned the discussion to carbon emissions from BRI projects and presented preliminary findings from his four-country case studies. He concluded that, on aggregate, the emissions impact of the BRI is still “more brown than green.” Twenty-eight percent of global carbon emissions may be accounted for by BRI projects, Ball asserted, underscoring the importance of the BRI to the future of global climate change.

The day concluded with presentations by  Michael Bennon, Managing Director at the Stanford Global Projects Center, and Professor David M. Lampton, Oksenberg-Rohlen Fellow at the Freeman Spogli Institute for International Studies. Bennon first presented findings from two empirical case studies of BRI projects and then went on to describe how the BRI is now practically the “only game in town” for infrastructure funding for developing countries. Lengthy environmental review processes at Western multilateral banks have turned the World Bank, for example, from a lending bank into a “knowledge bank,” he argued. He also highlighted that, in general, economic returns on BRI projects for China are very poor, even though recipient countries may accrue macroeconomic benefits from these projects. Finally, Professor Lampton turned the discussion back to Southeast Asia, where China is currently undertaking massive cross-border high-speed rail projects through eight ASEAN countries. He described how each host country had varying capacity to negotiate against its giant neighbor, and how the sequential implementation of these cross-border rail projects also had varying impacts on the negotiating positions of these host countries. BRI played out differently in each country, in other words, eliciting different reactions, push-backs and negotiated terms.

The second day of the workshop was dedicated to working toward a collaborative approach to future BRI research. The group discussed the key gaps in the existing research, including how to know what China’s true intentions are, how to measure those intentions, who the main players and their interests in both China and the host countries are, and even what the BRI is, exactly. Some cautioned that high-profile projects may not be representative of the whole. Participants brainstormed about existing and future sources of data, and stressed the importance of diversifying studies and seeking empirical evidence.

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Many mountainous and high‐latitude regions have experienced more precipitation as rain rather than snow due to warmer winter temperatures. Further decreases in the annual snow fraction are projected under continued global warming, with potential impacts on flood risk. Here, we quantify the size of streamflow peaks in response to both seasonal and event‐specific rain‐fraction using stream gage observations from watersheds across the western United States. Across the study watersheds, the largest rainfall‐driven streamflow peaks are >2.5 times the size of the largest snowmelt‐driven peaks. Using a panel regression analysis of individual precipitation and snowmelt events, we show that the empirical streamflow response grows approximately exponentially as the liquid precipitation input increases, with rain‐dominated runoff leading to proportionately larger streamflow increases than snowmelt or mixed rain‐and‐snow runoff. We find that the response to changes in rain percentage is largest in the wettest watersheds, where wet antecedent conditions are important for increasing runoff efficiency. Similarly, the effect of rain percentage is larger across watersheds in the Northwest and West regions compared to watersheds in the Northern Rockies and Southwest regions. Overall, as a higher percentage of precipitation falls as rain, increases in the size of rainfall‐driven and “rain‐on‐snow”‐driven floods have the potential to more than offset decreases in the size of snowmelt‐driven floods.

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American Geophysical Union Publications
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Marshall Burke
Noah Diffenbaugh
Authors
Beth Duff-Brown
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Global warming and more days of extreme heat are exacerbating the health risks of pregnancy, particularly among African-American women, according to new Stanford-led research.

The maternal mortality rate among all women in the United States is already the worst of any industrialized nation. And black women are three to four times more likely to die from pregnancy-related problems than white women.

“It is truly a crisis that in America, one of the wealthiest countries in the world, more women are dying from pregnancy or childbirth complications than in any other developed country,” said Maya Rossin-Slater, a core faculty member at Stanford Health Policy and a faculty fellow at the Stanford Institute for Economic Policy Research.

In a new working paper published by the National Bureau of Economic Research, Rossin-Slater and two other health economists underscore how little research is out there about the impact of rising temperatures on the health of mothers and their newborns.

Pregnant women, for example, are not able to regulate body temperature as efficiently as non-pregnant individuals due to the physiological changes they undergo during gestation. Heat exposure can alter blood flow in the placenta, which can weaken the placenta and lead to complications. And high heat can lead to other pregnancy complications, such as hypertension, preeclampsia and prolonged premature rupture of membranes.

“All of these issues can translate into women needing to be hospitalized during pregnancy and experiencing complications during childbirth,” wrote Rossin-Slater, an assistant professor of health research and policy at Stanford Medicine. Her co-authors are Jiyoon Kim, assistant professor of economics at Elon University, and Ajin Lee, an assistant professor of economics at Michigan State University.

The researchers said most of the discussion about maternal health focuses on the health-care system, but that other determinants of poor maternal health and racial disparities are much less understood, particularly when it comes to how the environment is impacting pregnancy.

So they launched what they believe is the first study to identify the causal effects of prenatal exposures to extreme temperatures on the health of the mothers themselves.

As the Earth Warms, So Does Exposure to Extreme Heat

Their paper focuses on an environmental factor that is becoming increasingly relevant due to the growing consensus that climate change is contributing to a gradual warming of the earth: exposure to extreme heat.

The researchers studied the effects of exposure to extreme temperatures during pregnancy on maternal and child hospitalizations, using inpatient discharge records from three U.S. states with different climates: Arizona, New York and Washington. Their data comes from the State Inpatient Databases from the Healthcare Cost and Utilization Project, including 2.7 million inpatient records of 2.7 million infants and 2.2 million mothers in those three states.

And to measure temperature exposure, the researchers obtained data from the National Oceanic and Atmospheric Administration (NOAA).

For every county in their data, the researchers calculated the average temperature for every month. Then for every given day in a specific month in that county, they looked at the historic average for how high or low that day’s temperature was relative to the overall temperature in that month in that county.

For example, a 90-degree day in Arizona in September would not be classified as extreme heat since it’s relatively common. But a 90-degree day in New York would be, since temperatures that high are much less common. They classified “extreme heat” as a given day when the temperature is more than three standard deviations (3SD) above that historic county mean.

Then, they compared the outcomes of women who are of the same race giving birth in the same county and calendar month, but in different years. These women are likely similar in terms of their demographics and socioeconomic status, but may be exposed to different temperatures during pregnancy. For example, consider a black woman giving birth in November 2011 in Queens County, New York, and a black woman giving birth in November 2012 in the same county. If there were a heat wave in Queens in the August 2012, then the latter woman is exposed to more extreme heat during pregnancy than the former. 

The economists found that each additional day with heat that is at least 3SDs — or substantially higher than the historic county-month average — during the second trimester of pregnancy increases the likelihood that a newborn is diagnosed with dehydration by .008 percentage points.

“Our results provide new estimates of the health costs of climate change and identify environmental drivers of the black-white maternal health gap,” they wrote. “Understanding the health consequences of this increase in extreme heat is critical information for discussions about the costs of climate change and the possible benefits of mitigating policies.”

The researchers found that each additional day of extreme heat exposure during pregnancy increases black women’s likelihood of hospitalization during pregnancy. Since black women on average are exposed to more extreme heat than white women — due to different residence patterns and access to mitigating technologies like air conditioning — extreme heat may contribute to exacerbating the already large gap in maternal health between black and white women.

Detrimental Consequences of Rising Temperatures

Scientists predict global average temperatures will continue to rise over the next 50 to 100 years as greenhouse gases continue to trap more heat in the Earth’s atmosphere. The U.N. Intergovernmental Panel on Climate Change last year warned that nations worldwide must quickly reduce fossil fuel use to keep the rise in global temperatures below 1.5°C by 2050. 

The panel also said the number of days with mean temperatures above 32°C in the average American county is forecasted to increase from about 1 to 43 days per year by 2070-2099.

That could have detrimental consequences for babies and mothers alike.

“Overall, our findings on infant health suggest that exposure to extreme heat during the second trimester increases the likelihood of the baby being dehydrated at the time of birth,” the researchers wrote. “This, in turn, appears to increase the likelihood of subsequent readmission to the hospital many months later for causes linked to dehydration.”

And these impacts are typically missed when researchers only measure infant health using more standard variables, such as birth weight.

The authors note dehydration is one of the leading causes of morbidity and mortality in children. Studies show that children under 5 years old who have an average of two episodes of gastroenteritis associated with dehydration per year leads to 2 to 3 million pediatric office visits and accounts for 10% of all pediatric hospital admissions in the United States. 

Experts believe black women are three- to four-times more likely to die from pregnancy-related causes due to lack of access to and the poor quality of health care, as well as clinicians not monitoring black women as closely — or actually dismissing their symptoms altogether.

“The fact that the adverse impacts on health during pregnancy are larger for black than for white mothers suggests that climate change may exacerbate the already large racial gap in maternal health,” the researchers said.

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