A rollercoaster of weather extremes: Drought and heat waves are creating UK's climate whiplash

A rollercoaster of weather extremes: Drought and heat waves are creating UK's climate whiplash Gaby Clark Scientific Editor Alexander Pol Deputy Editor The UK is bouncing from one type of extreme weather to another this year. This is climate whiplash. Caused by changes in the fast-moving body of air high in the atmosphere called the jet stream, climate whiplash has become more likely with climate change. These constant shifts in extreme weather make it challenging to build resilience. Drought and heat waves play a big role in this roller coaster of weather extremes. There are many different types of drought—in simple terms, drought is an absence of water from an area, meaning it is drier. For a drought to be declared in a region of the UK, the National Drought Group (chaired by the Environment Agency, which is responsible for droughts) meets, considers several factors and makes a decision. This process is similar to how the UK decides to name winter storms. There have traditionally been four key types of drought. Hydrological drought is when lakes and rivers drop below certain regional levels. Meteorological drought is based on how long it has been dry. Agricultural drought links a lack of rainfall to negative consequences for plant growth. Socio-economic drought happens when demand for water is higher than the available supply. There is also another relatively new type of drought—flash droughts, which are caused by hot, dry, windy weather that acts like a hair dryer. One of the main drivers of flash droughts in UK springs and summers is atmospheric evaporative demand. This is how thirsty the atmosphere is. In some parts of the UK, including parts of southern England, there are suggested flash drought conditions where the atmosphere has been thirstier than the available moisture. In most other parts, such as North Wales, we are simply experiencing a hydrological drought. When heat waves and drought or dry conditions occur together in the UK, they make each other more intense. Baking-dry ground causes air temperatures to rise. These conditions also raise the risk of wildfires. But heat waves are a separate hazard from drought. Heat is tricky because while we cannot see higher temperatures or hotter conditions, we feel extreme heat. This is why heat waves are sometimes called silent killers and an invisible risk. The deadliest heat waves can occur outside drought or dry conditions. This is because moisture in the air, or humidity, limits our ability to cool down. One way we measure this is through the wet-bulb temperature. Meteorologists measure this using a standard thermometer wrapped in wet muslin cloth—it indicates how difficult it is to lose heat through sweat. Drought is the absence of moisture, so reaching a higher wet-bulb temperature is physically more challenging and requires a lot more energy than when that moisture is present. Opportunities for change New research shows that many people in the UK are now fearful of climate change because of recent heat waves. While concern is important, it can lead to inaction and not knowing what to do. There are many solutions to build resilience to climate whiplash and multiple hazards in the UK. We need to reduce greenhouse gas emissions to net zero. Because we haven't mitigated greenhouse gas emissions quickly enough, climate whiplash is now intensifying globally. Investment needs to focus on transitioning faster by scaling up clean energy, restoring natural environments and building resilience. Climate change is also a social challenge. Tackling it can help address longstanding policy areas, social inequalities and emerging challenges. One of the main places where we see heat-related excess deaths outside hospitals is care homes. Mitigating and adapting to extreme weather can therefore be integrated into long-term social care planning. Unemployed young people can be upskilled to fill workforce gaps in green and climate-related jobs and clean energy sectors. This gives them a purpose and creates a more specialized workforce. Investment in and consideration of different models for the UK water industry can build resilience to multiple hazards. For droughts, this means storing water; for heat waves, accommodating increased pressure; and for flooding and excess rainfall, addressing risk. Schemes such as improving pipe infrastructure, wastewater treatment, reservoir construction and greater water sharing within relevant regions of the UK are also important. Policy can be set out by the UK government to ensure that people most vulnerable to extreme heat in care homes, schools and hospitals have access to air conditioning when they need it. Policy should also be designed with urban greening, retrofitting and long-term sustainable urban planning for extreme weather in mind. Energy resilience is also important and involves making use of sunnier days and building grid capacity to capture energy from renewable sources. While we may keep flashing from hot, dry conditions to wet and wild ones, the solutions are in front of us. Provided by The Conversation This article is republished from The Conversation under a Creative Commons license. Read the original article.