Facts About Extreme Weather

NIEHS provides information about many extreme weather events and conditions, such as heat waves which pose serious threats to health by dehydrating you quickly and inhibiting your ability to cool yourself off naturally.

Global warming is increasing the risk of extreme weather events by raising air and ocean temperatures due to human activities that produce greenhouse gases.

1. Hurricanes

Hurricanes are natural events which combine unrelenting winds with torrential rainfall to form one of the most dangerous weather events on Earth. Hurricanes have the power to cause devastating wind damage and even tornadoes; however, floodwaters pose the greatest danger. Hurricanes have been responsible for eight of the 10 costliest weather disasters ever in US history.

Hurricanes are large, rapidly rotating storms that gain strength as they pass over ocean waters, drawing energy from warm seawater and sucking it inward to produce fierce winds that swirl around a central low-pressure area. When seen from above, hurricanes appear as buzz saw-shaped storms; their center contains a circular area known as an eye wall which contains calmer conditions while outer cloud bands with thunderstorms provide stronger winds than their center.

Hurricane intensity depends on two key elements: how much heat it is drawing in and its pressure rise. Hurricanes are classified by their intensity on the Saffir-Simpson scale, with categories three through five being the most severe storms. Climate change has contributed to a rise in category four and five hurricanes due to warming temperatures increasing atmospheric temperature levels which makes intensification faster.

Major hurricanes are capable of inflicting widespread destruction, with category 5 storms often resulting in total building collapse and loss of lives. Along with wrecked houses and structures, major hurricanes also flood roads and bridges, cut power lines, destroy trees and vegetation and disrupt water supply systems – raising sea levels along coastal regions, leading to flooding and erosion.

Hurricanes have an enormous economic impact. On average, each storm costs $20 billion in damages – including physical property like cars and boats and lost income from destroyed businesses – as well as stressing communities that were unprepared. Climate change plays a large role in intensifying hurricanes by raising atmospheric temperatures, making storm formation more likely over warmer waters, and contributing to their severity.

2. Tornadoes

Tornadoes hold a special place in our collective imaginations and several popular movies have been made about this terrifying natural occurrence, with winds reaching 250 miles an hour that can tear buildings apart, destroy bridges and flip trains before sucking the water out of riverbeds. Tornadoes have been described as being funnel-shaped or the size of a football field when seen from space; their unpredictable passage often results in tremendous destruction that even kills people.

Tornadoes form when warm, moist air near the ground collides with cold, dry air in the upper atmosphere, creating spinning air currents which collide and collide into thunderstorms that eventually transform into tornadoes when rotating clouds push down on rain-laden air from below and pull back up again as their rotation pushes and pulls at it from above.

When this occurs in the United States, where tornadoes average about one per year on average, it can be devastating. Tornado Alley in ten states has seen its share of these dangerous storms; with tornadoes rated EF-5 (the most intense category) ripping buildings apart and flattening homes and schools before sending cars and trucks flying off course. Even less intense high winds can rip shingles from roofs and turn metal objects into deadly missiles that pose even greater threats than their severity would indicate.

Tornadoes can also occur when a cold front moves into an area experiencing warm air or when jet stream is moving at an insufficient speed, as well as when the prevailing wind pattern becomes unstable; increased shear can help decrease chances of tornadoes occurring.

Meteorologists use Doppler radar, satellites and weather balloons to keep an eye out for tornadoes when they strike; meteorologists must rely on Doppler radar, satellites and weather balloons as part of the monitoring system. Although scientists can more readily link other extreme weather events like drought or heavy rainfall with climate change than tornadoes due to complex factors that influence whether one forms, how quickly it travels and its severity; it could be that climate change has increased their frequency or strength over time.

3. Flooding

Floods are natural disasters caused when too much water inundates normally dry land. Flooding occurs when rivers reach their flood plain, when snow melts too rapidly or when dams or levees collapse; heavy rainfall is the primary cause, though floods tend to occur more often and severely after prolonged droughts.

Climate change leads to warmer weather, increasing heatwaves and droughts while simultaneously increasing flooding risks and wildfire risk. Warm air can trap more moisture than cool air; thus leading to more frequent and intense rainfall events due to more moisture absorption in warmer air masses. Climate change also raises sea levels, worsening storm surges and coastal erosion.

Extreme weather refers to any condition of unusual or out-of-the-ordinary climate for any given region. It often refers to an event with severe or unexpectedly extreme conditions, but can also include temperature extremes, hurricanes, tornadoes and floods. Extreme weather has devastating impacts on humans as well as natural ecosystems alike and is frequently associated with poverty and inequality.

Geography, climate and human population all play a part in creating extreme weather events, from geography and climate change to proximity of rivers or oceans and flooding risk. Furthermore, people can exacerbate extreme weather events through poor urban planning practices or the destruction of wetland areas.

Global warming, or anthropogenic climate change, is one of the primary drivers behind increased weather events and their severity. Carbon dioxide and methane emissions released into the atmosphere from burning fossil fuels act like blankets over Earth to trap heat, warming it further while altering weather patterns by melting glaciers, raising sea levels, making hurricanes and tornadoes stronger, as well as making floods more frequent and severe than ever. According to the Fourth National Climate Assessment conducted in the US this past May, more frequent and intense rain events led to frequent floods becoming more frequent and severe due to rising temperatures; specifically heavier rainfall events occur more regularly due to rising temperatures being in addition to heavier rainfall events. The Fourth National Climate Assessment found that floods were becoming more frequent and severe due to rising temperatures; specifically because heavier rain falls occurs more often due to rising temperatures as a result.

4. Heat Waves

Heat waves are periods of extremely hot weather that tend to have high humidity. They can pose serious health threats, including heat exhaustion and dehydration; increasing risk for heart attacks and strokes as well as being one of the main contributors to weather-related deaths worldwide.

Human-caused greenhouse gas emissions are exacerbating climate change, increasing the probability of heatwaves and other extreme weather events. Warm air holds more moisture, leading to heavy rainfall, flooding, droughts and wildfires around the globe – changes which have serious ramifications on people and wildlife alike.

Scientists rely on observations made at land, air and sea-based observations as well as climate models to study how extreme weather patterns have changed over time. Their measurements take into account ocean temperatures, sea levels, wind speeds and atmospheric conditions as part of their research process. Furthermore, scientists look back to historical records like temperature, rainfall and drought data and compare this with current conditions to spot any discrepancies or differences that exist.

Utilizing this data, scientists are able to use event attribution as an approach for understanding how climate change is contributing to natural disasters.

As evidenced in this chart, most attribution studies focus on extreme heat events; however, other events such as hurricanes and tornadoes may also be taken into consideration in studies on their attribution. Furthermore, research may investigate how climate change may influence El Nino events directly.

Studies of this nature are then used to update weather forecasts and models in order to prepare for future extreme events, helping mitigate their negative impact and protect lives and livelihoods from disaster.

People living in coastal and island regions, low-income communities, elderly persons and young children are especially susceptible to climate change’s extreme weather impacts and its potential impacts. When these events strike, these groups are more likely to lose their homes, access emergency services quickly or become sick as a result.