Warm Arctic episodes linked with increased frequency of extreme winter weather in the United States

Nature Communications, Год журнала: 2018, Номер 9(1)

Опубликована: Фев. 22, 2018

Recent boreal winters have exhibited a large-scale seesaw temperature pattern characterized by an unusually warm Arctic and cold continents. Whether there is any physical link between variability Northern Hemisphere (NH) extreme weather active area of research. Using recently developed index severe winter weather, we show that the occurrence in United States significantly related to anomalies pan-Arctic geopotential heights temperatures. As transitions from relatively state warmer one, frequency mid-latitudes increases through transition. However, this relationship strongest eastern US mixed even opposite along western US. We also during mid-winter late-winter recent decades, when warming trend greatest extends into upper troposphere lower stratosphere, weather-including both spells heavy snows-became more frequent States.

Язык: Английский

---

Integrated CO₂ Capture and Conversion to Formate and Methanol: Connecting Two Threads

Accounts of Chemical Research, Год журнала: 2019, Номер 52(10), С. 2892 - 2903

Опубликована: Сен. 5, 2019

ConspectusThe capture of CO2 from concentrated emission sources as well air represents a process paramount importance in view the increasing concentration atmosphere and its associated negative consequences on biosphere. Once captured using various technologies, is desorbed compressed for either storage (carbon (CCS)) or production value-added products utilization (CCU)). Among that can be synthesized CO2, methanol formic acid are high interest because they used directly fuels to generate H2 demand at low temperatures (<100 °C), making them attractive hydrogen carriers (12.6 4.4 wt % acid, respectively). Methanol already produced huge quantities worldwide (100 billion liters annually) also raw material many chemicals products, including formaldehyde, dimethyl ether, light olefins, gasoline. The through chemical recycling heart so-called "methanol economy" we have proposed with late Prof. George Olah our Institute. Recently, there has been significant progress low-temperature synthesis (or formate salts) homogeneous catalysts. Importantly, several studies combined hydrogenation, where (including air) was utilized produce CH3OH without requiring energy intensive desorption compression steps. This Account centers topic.A key feature conversion reported date use an amine alkali-metal hydroxide base capturing which assist catalysts hydrogenation step. We start this by examining processes solutions converted alkylammonium salts. effect basicity reaction rate discussed along catalyst schemes. Next, process, amines agents, explored. examine system developments effective process. next go molecular structure while elucidating main deactivating pathway involving carbonylation metal center. recent advances first-row transition mentioned. Subsequently, discuss bases regeneration (NaOH KOH) (80 °C) cation-conducting direct fuel cells presented. Finally, review challenges yet unreported integrated

Язык: Английский

---

A century of observations reveals increasing likelihood of continental-scale compound dry-hot extremes

Science Advances, Год журнала: 2020, Номер 6(39)

Опубликована: Сен. 24, 2020

Compound dry-hot events enlarge homogenously due to teleconnected land-atmosphere feedbacks.

Язык: Английский

---

Homogeneous and heterogeneous catalysts for hydrogenation of CO₂ to methanol under mild conditions

Chemical Society Reviews, Год журнала: 2021, Номер 50(7), С. 4259 - 4298

Опубликована: Янв. 1, 2021

This review summarizes the concepts, mechanisms, drawbacks and challenges of state-of-the-art catalysis for CO₂ to MeOH under mild conditions. Thoughtful guidelines principles future research are presented discussed.

Язык: Английский

---

Severity of drought and heatwave crop losses tripled over the last five decades in Europe

Environmental Research Letters, Год журнала: 2021, Номер 16(6), С. 065012 - 065012

Опубликована: Март 18, 2021

Abstract Extreme weather disasters (EWDs) can jeopardize domestic food supply and disrupt commodity markets. However, historical impacts on European crop production associated with droughts, heatwaves, floods, cold waves are not well understood—especially in view of potential adverse trends the severity due to climate change. Here, we combine observational agricultural data (FAOSTAT) an extreme disaster database (EM-DAT) between 1961 2018 evaluate responses EWD. Using a compositing approach (superposed epoch analysis), show that droughts heatwaves reduced cereal yields average by 9% 7.3%, respectively, wide range (inter-quartile +2% −23%; −17%). Non-cereal declined 3.8% 3.1% during same set events. Cold led non-cereal yield declines 1.3% 2.6%, while flood were marginal statistically significant. Production losses largely driven declines, no significant changes harvested area. While all four event frequencies significantly increased over time, heatwave drought roughly tripled last 50 years, from −2.2% (1964–1990) −7.3% (1991–2015). Drought-related shown intensify more than 3% yr −1 . Both trend frequency possibly be explained vulnerability exposed system underlying change impacts.

Язык: Английский

---

Responses of forest insect pests to climate change: not so simple

Current Opinion in Insect Science, Год журнала: 2019, Номер 35, С. 103 - 108

Опубликована: Авг. 2, 2019

Climate change is a multi-faceted phenomenon, including elevated CO2, warmer temperatures, more severe droughts and frequent storms. All these components can affect forest pests directly, or indirectly through interactions with host trees natural enemies. Most of the responses insect herbivores to climate are expected be positive, shorter generation time, higher fecundity survival, leading increased range expansion outbreaks. Forest pest also benefit from synergistic effects several pressures, such as hotter However, lesser known negative likely, lethal heat waves thermal shocks, less palatable tissues abundant parasitoids predators. The complex interplay between abiotic stressors, trees, their enemies makes it very difficult predict overall consequences on health. This calls for development process-based models simulate population dynamics under scenarios.

Язык: Английский

---

Increased Flood Exposure Due to Climate Change and Population Growth in the United States

Earth s Future, Год журнала: 2020, Номер 8(11)

Опубликована: Окт. 30, 2020

Abstract Precipitation extremes are increasing globally due to anthropogenic climate change. However, there remains uncertainty regarding impacts upon flood occurrence and subsequent population exposure. Here, we quantify changes in exposure hazard across the contiguous United States. We combine simulations from a model large ensemble high‐resolution hydrodynamic model—allowing us directly assess wide range of extreme precipitation magnitudes accumulation timescales. report mean increase 100‐year event ~20% (magnitude) >200% (frequency) high warming scenario, yielding ~30–127% further find nonlinear for most intense events—suggesting accelerating societal historically rare or unprecedented events 21st century.

Язык: Английский

---

Global surface air temperatures in CMIP6: historical performance and future changes

Environmental Research Letters, Год журнала: 2020, Номер 15(10), С. 104056 - 104056

Опубликована: Авг. 18, 2020

Abstract Surface air temperature outputs from 16 global climate models participating in the sixth phase of coupled model intercomparison project (CMIP6) were used to evaluate agreement with observations over land surface for period 1901–2014. Projections multi-model mean under four different shared socioeconomic pathways also examined. The results reveal that majority reasonably capture dominant features spatial variations observed a pattern correlation typically greater than 0.98, but large variability across and regions. In addition, CMIP6 can trends temperatures shown by observational data during 1901–1940 (warming), 1941–1970 (cooling) 1971–2014 (rapid warming). By end 21st century, scenarios is projected increase 1.18 °C/100 yr (SSP1-2.6), 3.22 (SSP2-4.5), 5.50 (SSP3-7.0) 7.20 (SSP5-8.5), warming high latitudes northern hemisphere weaker tropics southern hemisphere. Results probability density distributions further indicate increases frequency magnitude warm extremes may occur future.

Язык: Английский

---

Contribution of historical precipitation change to US flood damages

Proceedings of the National Academy of Sciences, Год журнала: 2021, Номер 118(4)

Опубликована: Янв. 11, 2021

Significance Precipitation extremes have increased in many regions of the United States, suggesting that climate change may be exacerbating cost flooding. However, impact historical precipitation on US flood damages remains poorly quantified. Applying empirical analysis to and damages, we estimate approximately one-third (36%) over 1988 2017 is a result changes. Climate models show anthropogenic has probability heavy associated with these costs. Our results provide information quantifying costs change, suggest lower levels future warming would very likely reduce flooding losses relative current global trajectory.

Язык: Английский

---

Determinants of emissions pathways in the coupled climate–social system

Nature, Год журнала: 2022, Номер 603(7899), С. 103 - 111

Опубликована: Фев. 16, 2022

Язык: Английский

---