The scientists behind a new database of more than 400 extreme weather attribution studies have performed an essential service. This piece of work, drawing together every study of this type, ought to galvanise a greater sense of urgency around policymaking and campaigning. It shows that intense heatwaves, hurricanes, droughts and floods have all been made far more likely by greenhouse gas emissions, which trap the sun’s heat and put more energy into weather systems. And it spells out the alarming unpredictability as well as the extent of global heating’s consequences.
Until the early 2000s, when the first attribution studies were published, it was harder to link CO2 in the atmosphere with global heating’s tangible effects. Thanks to a growing body of research, now we know. The record-breaking “heat dome” over north-western Canada and the US last summer would have been almost impossible without human-caused climate change. The same is true of heatwaves across the northern hemisphere in 2018, and in Asia in 2016.
Wildfires in Siberia in 2020 were made 80% more likely by global heating, while 90% of marine heatwaves are human-caused. An increased mortality rate is evident on every continent, with scientists estimating 100,000 deaths each year. Heating was a factor in the California drought of 2012-14 and the super-typhoon Haiyan in the Philippines. While extreme weather in China has been studied, far less research has been conducted in Africa and South America. Yet again, those parts of the world that are most exposed to climate change find themselves with the fewest resources to help them understand and address it.
“Beauty is truth, truth beauty,” wrote the poet John Keats just over 200 years ago. When it comes to climate, truth can feel closer to terror these days. But scientists and leaders, including the UN secretary general, António Guterres, the former UN climate chief, Christiana Figueres, and the Cop26 president, Alok Sharma, are right to insist that the reality must be faced. Indeed, this is the only way to avoid the most catastrophic and tragic outcomes. In a new book, Hothouse Earth, Prof Bill McGuire argues that we have reached a stage when minimising dangers should be regarded as “climate appeasement”.
Like the historical responsibility for carbon emissions, attitudes and experiences in the present crisis are unevenly and unjustly shared out. Billions of people around the world, and above all in the global south, are caught up day-to-day in a struggle for survival. This doesn’t mean they don’t recognise global heating; subsistence farmers and fishers are more directly exposed to environmental damage than anyone else. But western governments, businesses and people who are relatively shielded from global heating’s worst effects should recognise this as the privilege that it is.
With this year’s Cop27 in Egypt fast approaching, western governments must follow through on their pledges of climate finance to enable a green transition in the developing world. The purpose of attribution science is not simply to warn the world about what is happening, but to aid preparations for what has not happened yet. The most alarming global trend, apart from still-rising emissions that mean we are on course for 2.5C of heating, is the unexpected speed with which it is already causing chaos. Given what we now know about the impact of 1C of warming, it is no exaggeration to say that this trajectory is not only suicidal but murderous.
But alternatives exist, and insisting on this point has never been more important. Ms Figueres, who delivered the Paris agreement, called this week for a “sprint toward the light”. The alarming findings of attribution scientists can give rise to desperation – but must not be allowed to extinguish determination and hope.
