Heat waves and their effect on the environment

“I don't know how many more warnings the world needs. It is as if the human race had received a terminal medical diagnosis and knew there is a cure, but consciously chose not to save itself”

With these blunt words, Professor Lesley Hughes of Macquire University in Sydney, Australia, warned readers of The Guardian in an interview published last year. In her own country, Australia, the consequences of heatwaves have been devastating, with temperatures reaching 45ºC and numerous episodes of drought and devastating fires in recent years.

Australia's case, however, is not isolated. Global temperatures have been rising year after year, threatening many animal species, including humans. Last summer saw record-breaking temperatures and extreme weather events, and this summer, which is about to begin, is expected to surpass previous records.

Sadly, this last sentence is very likely to be read or heard many times in the years to come. And it will be true every time. 

Implications for human health 

Heat waves pose a serious threat to human health, both by exacerbating pre-existing medical conditions and by causing new emergencies. High temperatures are a key factor in increasing the risk of cardiovascular and respiratory conditions, as well as causing a higher incidence of heat stroke, dehydration and heat exhaustion. Children, the elderly and people with chronic illnesses are particularly vulnerable to these events. 
 

Furthermore, heat waves can have psychological consequences, such as heat-related stress and anxiety linked to climate change. These mental health issues can, in turn, have social and political consequences. The hopelessness and unease caused by climate anxiety can lead to extreme positions and more contentious societies.

Environmental impact of heat waves

The most visible and drastic effects of heat waves, however, are their impact on environmental health. In recent years we have seen how, as a result of high temperatures, the migratory flows of animals have changed and spiralled out of control. Some ecosystems have even broken down, becoming hostile for the very species they once supported. These factors contribute, and will continue to contribute, to loss of biodiversity, and the extinction of several species. 

On the other hand, due to high temperatures, long periods of drought are more frequent and, consequently, forest fires occur more often. The large forest fires that have been seen in recent years emit greenhouse gases, adding to the damage.

Finally, high temperatures also contribute to ocean acidification, with devastating effects on coral reefs and the survival of marine species. In fact, in recent years, it has not been uncommon to see beaches with large amounts of fish dead due to the temperature of the water. 

Economic and social impact 

Heat waves not only pose a threat to health and the environment, but also have serious economic and social implications. Extreme working conditions can lead to a significant reduction in labour productivity, damaging the economy, especially in sectors such as agriculture, construction and tourism.

Droughts can lead to changes in how plants grow, affecting food production. This leads to significant agricultural losses and increased difficulty in procuring food for everybody. Furthermore, high temperatures also increase energy demand for cooling. Air conditioning is becoming increasingly indispensable in periods of extreme heat, thus generating higher energy costs, as it is usually obtained from non-renewable energy sources that have a significant carbon footprint.

Heatwaves are creating a multi-dimensional impact that requires an urgent and coordinated global response. The adoption of adaptation and mitigation policies, as well as the promotion of sustainable practices, are essential to meet this climate challenge and ensure a safe and prosperous future for the next generations.