Changes in temperature cause changes in rainfall. This results in more severe and frequent storms

Changes in Temperature Cause Changes in Rainfall: Implications for Extreme Weather Events

Introduction

Climate change is one of the most pressing challenges facing humanity and the planet. It is caused by the increase of greenhouse gases (GHGs) in the atmosphere, mainly from the burning of fossil fuels. These gases trap heat and make the Earth warmer than it should be. This has many negative impacts on the environment, wildlife, and human health.

One of the effects of climate change is the alteration of the water cycle, which is the continuous movement of water between the land, oceans, and atmosphere. The water cycle is essential for life on Earth, as it provides fresh water for drinking, agriculture, and hydropower, and regulates the climate by transferring heat and moisture. However, climate change is disrupting the water cycle in various ways, such as changing the amount, timing, and distribution of precipitation (rain and snow), increasing evaporation, and affecting soil moisture and runoff.

In this article, we will focus on how changes in temperature cause changes in rainfall, and how this results in more severe and frequent storms. We will also discuss some of the consequences of these changes for different regions and sectors of society.

How does temperature affect rainfall?

Temperature is one of the main factors that influence rainfall. This is because temperature affects the amount of water vapor that the air can hold. Water vapor is the gaseous form of water that is invisible to the naked eye. It is produced by evaporation from water bodies or transpiration from plants. It is also removed from the air by condensation into liquid or solid forms when it cools down.

The relationship between temperature and water vapor is governed by a physical law called the Clausius-Clapeyron equation¹. This equation states that for each degree Celsius of warming, the air’s capacity for water vapor goes up by about 7 percent². This means that warmer air can hold more moisture than cooler air.

An atmosphere with more moisture can produce more intense precipitation events, which is exactly what has been observed. According to a report by the Intergovernmental Panel on Climate Change (IPCC), there is high confidence that global precipitation has increased by about 1 to 2 percent per decade since 1951³. Moreover, there is medium confidence that heavy precipitation events have increased in frequency and intensity over most land areas since 1950³.

How does rainfall affect storms?

Storms are weather phenomena that involve strong winds, thunder, lightning, rain, snow, or hail. They are caused by the movement and interaction of air masses with different temperatures, pressures, and humidity levels. Storms can be classified into different types depending on their size, location, and origin. Some examples are tropical cyclones (hurricanes or typhoons), extratropical cyclones (mid-latitude storms), thunderstorms, tornadoes, and blizzards.

Rainfall plays a key role in the formation and development of storms. This is because rainfall releases latent heat into the atmosphere. Latent heat is the energy that is stored or released when water changes its phase (from solid to liquid to gas or vice versa). For example, when water vapor condenses into raindrops, it releases latent heat that warms up the surrounding air. This creates an upward motion of air that lowers the pressure at the surface. This pressure difference drives winds that converge toward the center of the storm. The stronger the winds, the stronger the storm.

Climate change is likely causing parts of the water cycle to speed up as warming global temperatures increase the rate of evaporation worldwide⁵. More evaporation means more water vapor in the atmosphere, which means more rainfall and more latent heat release. This can enhance the intensity and frequency of storms in some regions.

However, not all regions will experience more storms due to climate change. Some regions may experience less rainfall and more droughts as a result of changes in atmospheric circulation patterns or land surface feedbacks⁵. For example, some studies suggest that climate change may reduce the number of tropical cyclones in some ocean basins due to increased wind shear or reduced sea surface temperatures. Therefore, the effects of climate change on storms are complex and vary depending on local factors.

What are some of the impacts of more severe and frequent storms?

More severe and frequent storms can have significant impacts on various aspects of society and nature. Some of these impacts are:

- Damage to infrastructure: Storms can cause damage to buildings, roads, bridges, power lines, communication networks, and other infrastructure due to strong winds, heavy rains, flooding, landslides, or storm surges. This can disrupt essential services such as transportation, electricity,

water supply, health care, education, and communication. The cost of repairing or replacing damaged infrastructure can be very high.

- Loss of lives and livelihoods: Storms can cause injuries or deaths to people and animals due to flying debris, falling trees, electrocution, drowning, or exposure to extreme temperatures. Storms can also destroy crops, livestock, fisheries, and forests that provide food, income, and resources for millions of people. Storms can also trigger or worsen humanitarian crises such as displacement, migration, conflict, or poverty.

- Environmental degradation: Storms can alter the natural environment in various ways, such as eroding the soil, changing the hydrology, polluting the water, or altering the habitats of plants and animals. Storms can also contribute to the loss of biodiversity and ecosystem services that support human well-being. For example, storms can damage coral reefs that provide coastal protection, fishery production, and tourism revenue.

- Psychological distress: Storms can cause emotional stress, anxiety, depression, or post-traumatic stress disorder (PTSD) among people who experience or witness them. Storms can also affect the mental health of people who are indirectly affected by them, such as those who lose their loved ones, homes, or jobs. Storms can also create a sense of uncertainty, fear, or helplessness about the future.

Conclusion

Climate change is affecting the water cycle in various ways, such as changing the amount, timing, and distribution of rainfall. This is mainly due to the increase in temperature that affects the amount of water vapor that the air can hold. More water vapor means more rainfall and more latent heat release. This can result in more severe and frequent storms in some regions.

More severe and frequent storms can have significant impacts on various aspects of society and nature. Some of these impacts are damage to infrastructure, loss of lives and livelihoods, environmental degradation, and psychological distress. These impacts can pose serious challenges for adaptation and resilience.

Therefore, it is imperative to take urgent actions to mitigate climate change by reducing GHG emissions and enhancing carbon sinks. It is also important to adapt to the changes that are already happening by improving disaster risk management, strengthening infrastructure, enhancing social protection, restoring ecosystems, and promoting mental health.