What you need to know about heat waves – and why it will surprise you

What you need to know about heat waves – and why it will surprise you

Climate change is real, and intense and rising heat waves are part of that reality. But that is not the end of the story. Here are five things everyone should know about heat waves – some bad news, some surprising news and even some good news.

1) There is a strong connection with climate change, almost everywhere.

Heat waves, such as the one that is breaking temperature records across the UK and Europe this week, are the weather phenomena scientists have the greatest confidence in linking to man-made climate change.

The Intergovernmental Panel on Climate Change used its strongest language in describing heat waves in its latest assessment, stating with practical certainty that they have become more frequent and more intense globally since 1950, with greenhouse gas emissions being the main driver of these changes.

2) However, the connection is not as strong in the USA.

It will probably come as a surprise to many, but the United States is one of the exceptions to the global trend. The IPCC is far less sure of an upward trend in heat waves in America since 1900, noting that large-scale agriculture and associated irrigation may have helped limit extreme summer heat.

In fact, the US government’s latest national climate assessment concluded that the frequency of US heat waves has increased since the 1960s – but they have not yet reached levels observed during the first 40 years of the last century. And by using an index that was first presented in a paper I co-authored, the US NCA concludes that the intensity of American heat waves remains far below those observed in the 1920s and 1930s. As hot as it is today, it has been worse.

These are not as common in the United States.
Heat waves now hit areas that have not traditionally received them, such as London.
Getty pictures

3) No one needs to die of extreme heat.

Heat waves are common around the world and are becoming more common in places that only experienced them rarely, such as London. The hard-earned experience means that we have developed a good understanding of how we can keep people safe in extreme temperatures. A recent study of American heat wave mortality finds a steady decline in risk since the 1970s, even as the population has grown and the incidence of heat waves has increased.

Looking to the future, even with the IPCC estimating that heat waves will continue to rise, the World Health Organization claims that with the right adaptive responses, no one needs to die from heat. Knowing what to do and do it is of course two different things, which means that we must prioritize better adaptation to extreme weather conditions.

4) Heat waves are likely to become more common and more intense.

This will come for a greater need for energy.
Air conditioning and other cooling mechanisms will become more integrated parts of life.
AFP via Getty Images

Another place the IPCC expresses its strongest confidence is in its heat wave projections, practically certain heat waves will become more frequent and intense. It estimates that these increases will occur across future scenarios, with larger future emissions associated with a larger increase in heat waves. This means that no matter how fast the world continues to act to reduce fossil fuel consumption, improved adaptation will be needed no matter what.

5) The world is going to need a lot more air conditioning, and that means a lot more energy.

More heat means more demand for air conditioning. The International Energy Agency estimates that there are around 2 billion air conditioners in the world today. This number is expected to almost triple by 2050, with most of the growth in India and China and elsewhere. In the United States, about 90% of households already have air conditioning. In India, it is only around 5%, but is likely to grow rapidly in the coming decades. More air conditioning means more energy consumption – the IEA estimates that 37% of the increase in electricity consumption by 2050 will be due to cooling.

The increased demand means that we must prioritize both more efficient air conditioning technologies and distribute more carbon-free energy supply, such as nuclear power, wind and solar. Until we do, we should fully expect that fossil fuels will drive increased air conditioning, because if the choice is between being hot and being cool, we know that people around the world will choose cool, regardless of energy supply, just as we do here in the United States.

Heat waves are a fact. So also that they will become more common and intense. This means that we must double our efforts to prepare so that when heat waves occur, the damage is limited.

Roger Pielke Jr. is Professor of Environmental Studies at the University of Colorado Boulder. He writes about science, politics and politics at The Honest Broker, rogerpielkejr.substack.com.

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