Extreme event attribution, also known as attribution science, is a relatively new field of study in meteorology and climate science that tries to measure how ongoing climate change directly affects extreme events (rare events), for example extreme weather events. [1] [2] Attribution science aims to determine which such recent events can be explained by or linked to a warming atmosphere and are not simply due to natural variations. [3]
Attribution science was first mentioned in a 2011 "State of the Climate" published by the American Meteorological Society which stated that climate change is linked to six extreme weather events that were studied. [4]
German climatologist Friederike Otto posited that attribution science aims to answer the question, "did climate change play a role" in specific extreme events "within the news time frame – so within two weeks of the event". [5]
Attribution studies generally proceed in four steps: (1) measuring the magnitude and frequency of a given event based on observed data, (2) running computer models to compare with and verify observation data, (3) running the same models on a baseline "Earth" with no climate change, and (4) using statistics to analyze the differences between the second and third steps, thereby measuring the direct effect of climate change on the studied event. [3] [5]
Heatwaves are the easiest weather events to attribute. [3]
Climate change can affect the intensity and frequency of extreme weather differently, for example the 2010 Russia heat wave was made far more likely but not more intense. [3]
Attribution science may affect climate change litigation, perhaps by increasing lawsuits against companies for causing and governments for not addressing climate change. [6] [7]
A natural disaster is the highly harmful impact on a society or community following a natural hazard event. Some examples of natural hazard events include: flooding, drought, earthquake, tropical cyclone, lightning, tsunami, volcanic activity, wildfire. A natural disaster can cause loss of life or damage property, and typically leaves economic damage in its wake. The severity of the damage depends on the affected population's resilience and on the infrastructure available. Scholars have been saying that the term natural disaster is unsuitable and should be abandoned. Instead, the simpler term disaster could be used, while also specifying the category of hazard. A disaster is a result of a natural or human-made hazard impacting a vulnerable community. It is the combination of the hazard along with exposure of a vulnerable society that results in a disaster.
Extreme weather includes unexpected, unusual, severe, or unseasonal weather; weather at the extremes of the historical distribution—the range that has been seen in the past. Extreme events are based on a location's recorded weather history. They are defined as lying in the most unusual ten percent. The main types of extreme weather include heat waves, cold waves and heavy precipitation or storm events, such as tropical cyclones. The effects of extreme weather events are economic costs, loss of human lives, droughts, floods, landslides. Severe weather is a particular type of extreme weather which poses risks to life and property.
A heat wave, sometimes described as extreme heat, is a period of abnormally hot weather. High humidity often accompanies heat waves. This is especially the case in oceanic climate countries. Definitions vary but are similar. A heat wave is usually measured relative to the usual climate in the area and to normal temperatures for the season. Temperatures that humans from a hotter climate consider normal, can be regarded as a heat wave in a cooler area. This would be the case if the warm temperatures are outside the normal climate pattern for that area. Heat waves have become more frequent, and more intense over land, across almost every area on Earth since the 1950s. This is due to climate change.
Climate change affects the physical environment, ecosystems and human societies. Changes in the climate system include an overall warming trend, more extreme weather and rising sea levels. These in turn impact nature and wildlife, as well as human settlements and societies. The effects of human-caused climate change are broad and far-reaching. This is especially so if there is no significant climate action. Experts sometimes describe the projected and observed negative impacts of climate change as the climate crisis.
Severe weather is any dangerous meteorological phenomenon with the potential to cause damage, serious social disruption, or loss of human life. Types of severe weather phenomena vary, depending on the latitude, altitude, topography, and atmospheric conditions. High winds, hail, excessive precipitation, and wildfires are forms and effects of severe weather, as are thunderstorms, downbursts, tornadoes, waterspouts, tropical cyclones, and extratropical cyclones. Regional and seasonal severe weather phenomena include blizzards (snowstorms), ice storms, and duststorms.
Polar amplification is the phenomenon that any change in the net radiation balance tends to produce a larger change in temperature near the poles than in the planetary average. This is commonly referred to as the ratio of polar warming to tropical warming. On a planet with an atmosphere that can restrict emission of longwave radiation to space, surface temperatures will be warmer than a simple planetary equilibrium temperature calculation would predict. Where the atmosphere or an extensive ocean is able to transport heat polewards, the poles will be warmer and equatorial regions cooler than their local net radiation balances would predict. The poles will experience the most cooling when the global-mean temperature is lower relative to a reference climate; alternatively, the poles will experience the greatest warming when the global-mean temperature is higher.
Climate change in California has resulted in higher than average temperatures, leading to increased occurrences of drought and wildfires. During the next few decades in California, climate change is likely to further reduce water availability, increase wildfire risk, decrease agricultural productivity, and threaten coastal ecosystems. The state will also be impacted economically due to the rising cost of providing water to its residents along with revenue and job loss in the agricultural sector. California has taken a number of steps to mitigate impacts of climate change in the state.
Climate change has led to the United States warming by 2.6 °F since 1970. The climate of the United States is shifting in ways that are widespread and varied between regions. From 2010 to 2019, the United States experienced its hottest decade on record. Extreme weather events, invasive species, floods and droughts are increasing. Climate change's impacts on tropical cyclones and sea level rise also affects regions of the country.
Climate change can affect tropical cyclones in a variety of ways: an intensification of rainfall and wind speed, a decrease in overall frequency, an increase in the frequency of very intense storms and a poleward extension of where the cyclones reach maximum intensity are among the possible consequences of human-induced climate change. Tropical cyclones use warm, moist air as their source of energy or "fuel". As climate change is warming ocean temperatures, there is potentially more of this fuel available.
An atmospheric river (AR) is a narrow corridor or filament of concentrated moisture in the atmosphere. Other names for this phenomenon are tropical plume, tropical connection, moisture plume, water vapor surge, and cloud band.
The effects of climate change on human health are increasingly well studied and quantified. Rising temperatures and changes in weather patterns are increasing the frequency and severity of heat waves, wildfires, droughts, floods, landslides, hurricanes, and other causes of injury and illness. Heat waves and extreme weather events have a big impact on health both directly and indirectly. Direct effects of exposure to high and extended temperatures include illness, reduced labour capacity for outdoor workers, and heat-related mortality.
Climate change in Alabama encompasses the effects of climate change, attributed to man-made increases in atmospheric carbon dioxide, in the U.S. state of Alabama.
Wildfires can happen in many places in the United States, especially during droughts, but are most common in the Western United States and Florida. They may be triggered naturally, most commonly by lightning, or by human activity like unextinguished smoking materials, faulty electrical equipment, overheating automobiles, or arson.
In 2018, several heat waves with temperatures far above the long-time average and droughts were recorded in the Northern Hemisphere: The earth's average surface temperature in 2018 was the fourth highest in the 140 years of record keeping. It is assumed that the jet stream is slowing down, trapping cloudless, windless and extremely hot regions of high pressure. The jet stream anomalies could be caused by polar amplification, one of the observed effects of global warming.
Friederike (Fredi) Elly Luise Otto is a climatologist who as of December 2021 works as a Senior Lecturer at the Grantham Institute for Climate Change and the Environment at Imperial College London. She is an Honorary Research Associate of the Environmental Change Institute (ECI) at the University of Oxford. Her research focuses on answering the question whether and to what extent extreme weather conditions change as a result of external climate drivers. A highly recognized expert in the field of attribution research, she examines the extent to which human-caused climate change as well as vulnerability and exposure are responsible for events such heat waves, droughts and floods. Together with climate scientist Geert Jan van Oldenborgh she founded the international project World Weather Attribution which she still leads. In 2021, she was included in the Time 100, Time's annual list of the 100 most influential people in the world. She was also one of ten scientists who had had important roles in scientific developments in 2021 highlighted in the scientific journal Nature.
This article documents events, research findings, scientific and technological advances, and human actions to measure, predict, mitigate, and adapt to the effects of global warming and climate change—during the year 2020.
Amir AghaKouchak is an Iranian American civil engineer, academic and researcher. He is a Professor of Civil Engineering, Environmental Engineering, and Earth System Science at University of California, Irvine.
The climate in Texas is changing partially due to global warming and rising trends in greenhouse gas emissions. As of 2016, most area of Texas had already warmed by 1.5 °F (0.83 °C) since the previous century because of greenhouse gas emissions by the United States and other countries. Texas is expected to experience a wide range of environmental impacts from climate change in the United States, including rising sea levels, more frequent extreme weather events, and increasing pressure on water resources.
World Weather Attribution is an academic collaboration studying extreme event attribution, calculations of the impact of climate change on extreme meteorological events such as heat waves, droughts, and storms. When an extreme event occurs, the project computes the likelihood that the occurrence, intensity, and duration of the event was due to climate change. The project specializes in producing reports rapidly, while news of the event is still fresh.
Geert Jan van Oldenborgh was a Dutch climatologist and physicist. Through his career he studied climate modelling of adverse weather events and was known as a pioneer of attribution science, driving public awareness of how climate change is linked to extreme weather events. He was also the creator of a digital platform, Climate Explorer, an online meteorological data repository and platform for climate data analysis.