Some people \u2013 and media organisations \u2013 still have difficulty connecting the heatwaves currently gripping much of the world and human-caused climate chaos. Others are in outright denial. So how to address their evasions, distractions and lies?<\/p>\n
The Guardian has trawled through climate sceptics\u2019 claims and put their doubts to one of the UK\u2019s top climate scientists, Prof Ed Hawkins at the University of Reading.<\/p>\n
As the inventor of the famous \u201cclimate stripes\u201d graphic<\/a>, which visually represents the change in temperature as measured in each country, region or city over at least a century, he has arguably done as good a job in communicating global heating as anyone. Here are his responses to those who ignore or downplay the truth.<\/p>\n It has been hot, but mostly bearable. Can\u2019t we just get used to this as the new normal?<\/p>\n The \u201cnormal\u201d for humans and other life is fundamentally changing: high temperatures today are likely to seem cool in comparison with those of the future. The warmest 10 years on record have all happened in the past decade. And while an average global increase of 1C or 1.5C doesn\u2019t sound like much \u2013 and might even seem quite nice on a typical day \u2013 that is not how we experience a changing climate. The extremes are often changing faster than the mean. For example, while the global average rose by 1C, heatwaves in southern England have become 3C hotter.<\/p>\n Scientists disagree on how much humanity is affecting the climate, right?<\/p>\n No. We are certain that global warming is caused by human activities, primarily burning fossil fuels such as gas, oil and coal. Every heatwave and every summer is hotter than it would otherwise have been without those greenhouse gas emissions. That\u2019s the simple message from climate scientists and experts around the world.<\/p>\n Heavy haze as pollution and steam rise from the stacks of Miami Fort power station in Ohio. Photograph: Jason Whitman\/NurPhoto\/ShutterstockThis is a complex subject and there are degrees of uncertainty. Isn\u2019t there room for doubt?<\/p>\n The physics and chemistry are very simple: the more we increase greenhouse gas levels in the atmosphere, the more we will warm the climate. Those basics have been known since the 1850s, with the first quantification of the effect of increasing carbon dioxide levels being made in the 1890s.<\/p>\n In 1938, Guy Callendar, an English steam engineer, was the first person to show that the world had already warmed by about 0.3C, and linked this to the rise in carbon dioxide levels in the atmosphere and the amount of coal that had been burned. That was more than 80 years ago. Today, the evidence is overwhelming. There is no doubt among scientists even if other people still refuse to believe it.<\/p>\n Aren\u2019t heatwaves this year caused by natural weather cycles? I heard it was because of El Ni\u00f1o<\/p>\n We\u2019ve always had, and we\u2019ll always have in the future, times when the weather patterns align to give us extreme weather such as heatwaves and floods. But now the consequences are worse because of our warmer world.<\/p>\n El Ni\u00f1o is a natural fluctuation every few years in temperatures in the tropical Pacific, which affects weather patterns around the world but especially in South America, the US, Africa, Australia and parts of Asia. But the current El Ni\u00f1o<\/a> has just started and won\u2019t be peaking until around Christmas of this year \u2013 and is forecast to be a very big one.<\/p>\n Harvests are suffering because of hot, dry periods. Photograph: Charlie Riedel\/APHow about the theory that this is happening because the Earth\u2019s orbit is moving closer to the sun?<\/p>\n The Earth\u2019s orbit around the sun does affect our climate on very long timescales, over tens of thousands of years. At the time of the invention of the steam engine in the 18th century, this was pushing the Earth on to a slightly cooler path. Yet, what we have seen instead is a very rapid warming, which is not caused by the changes in the Earth\u2019s orbit. It is because the Industrial Revolution led to the burning of many more fossil fuels.<\/p>\n Many remember the 1976 heatwave in the UK. How is this summer any different?<\/p>\n There has been a big change in our climate in recent decades. In 1976, northern Europe was an isolated hotspot surrounded by regions experiencing a relatively cool summer. But the peak of the heatwave in June<\/a> this year was about two degrees hotter than June 1976 in the UK and shattered records over a wide area of Europe. Southern Europe and other regions around the world have shattered records in recent summers too.<\/p>\n Back in 1976, the conditions were very unusual. The UK experienced two weeks where temperatures peaked above 32C (89.6F) each day, and that came at the end of a year-long drought. There were severe water shortages and many schools had to shut or close early. About 250 extra people died each day during the heatwave. If comparable weather patterns were replicated in today\u2019s hotter world, the heatwave would be more dangerous<\/a>.<\/p>\n People in the fountain at Trafalgar Square in London in summer 1976. Photograph: Mirrorpix\/Getty ImagesI have read there is no way to determine whether any particular extreme weather event is caused by human-driven climate change. Is that true?<\/p>\n Climate change doesn\u2019t cause the weather patterns that lead to extreme events. But when those weather patterns do occur, like they have always done, climate change makes the consequences more severe, such as hotter heatwaves or heavier rainfall. That amplification can be estimated with attribution studies<\/a>, which consider how climate change has affected the likelihood or intensity of extreme weather events.<\/p>\n There are any number of different approaches to attribution now and they all show that, yes, these heatwaves are becoming hotter as a result of human activities. They may disagree slightly on the precise amount, but they\u2019re all consistent in the big picture.<\/p>\n Aren\u2019t human records too short to show clear trends?<\/p>\n Temperature records go back to the early 1800s. Since then, it\u2019s very clear that the world has become a lot hotter. The last time the world was as hot as it is now was about 125,000 years ago. We also have much older ice-core records dating back hundreds of thousands of years that show how much carbon dioxide and other gases were in the atmosphere. They reveal that the levels of CO2 today have risen to a high that exceeds anything in the ice cores. That increase is mainly down to our actions of burning fossil fuels and deforestation.<\/p>\n graph showing rise in central England’s average temperature over the last 175 years<\/a><\/p>\n In the very distant past, millions and billions of years ago, the Earth had a very different climate but we weren\u2019t there to experience it so it didn\u2019t matter. What ultimately matters is what we are experiencing as humans living through this current age of far more rapid warming than anything seen in the past.<\/p>\n Heatwaves usually bring to mind happy images of beaches, ice-cream and sun bathers. Why can\u2019t we just enjoy it?<\/p>\n Lots of people will be having fun. But plenty of others are not so fortunate \u2013 those who are vulnerable to heat owing to health conditions such as heart disease or diabetes, elderly people, children at school unable to keep cool, patients recovering in hospitals or workers in overheated workplaces. For these groups, a heatwave can be a miserable experience. When temperatures become very high, even fit and able people are at risk.<\/p>\n