The world is getting warmer: that much is certain. According to a 2020 report by the World Meteorological Organization (WMO), the global mean surface temperature last year was approximately 1.2°C warmer than the pre-industrial baseline (1850-1900); while the most recent decade, between 2011 and 2021, was the warmest on record. And although energy-related CO2 emissions did fall last year by 5.8 percent as a result of the COVID-19 pandemic, total global greenhouse emissions still increased year-on-year. The underlying trend is clear, the curves of most climate change graphs continue to snake upwards with alarmingly consistency.
There is also growing evidence that the steady rise in global surface temperatures is having a significant impact on the number, frequency and duration of natural hazards. Oxfam estimates the number of climate-related disasters has tripled in the last 30 years, and that more than 20 million people are being forced from their homes by climate change each year. The human and economic costs are staggering: the UN Environment Programme (UNEP) estimates that developing countries are already spending USD 70 billion a year to adapt to climate change. This figure is expected to rise to between USD 140-300 billion in 2030 and USD 280-500 billion in 2050.
Weather or climate?
However, although the general trend of rising global temperatures is easy to see, it is harder to gauge the precise impact of climate change on specific extreme weather events – including hurricanes, typhoons, floods, wildfires and heatwaves – as John Scott, Head of Sustainability Risk for Zurich Insurance Group, explains.
“It’s a complex task to disentangle the natural variations in extreme weather from the effects of climate change. While some climate change impacts are already obvious, such as retreating glaciers and sea level rise from melting land ice, the impact on today’s weather is harder to interpret,” Scott says. But although the modelling challenge, like the world’s weather systems, is fiendishly complex, meteorologists and climate scientists now understand that prolonged periods of heat and cold, are most closely attributable to ongoing global warming.
On land, rising surface temperatures are connected to the likelihood and severity of droughts and wildfires in hot, arid regions. The oceans too are heating up: the 0-2,000-meter layer of the global ocean reached a record high temperature in 2019, with a preliminary analysis of the 2020 data suggesting that it has surpassed that record.
Fueling dangerous storms
Rising temperatures and warmer seas mean that more water vapor is evaporating into the atmosphere, providing the ‘fuel’ for hurricanes, typhoons, and torrential rain. “If we are creating an atmosphere more loaded with humidity,” says George Tselioudis, a research scientist at Columbia University, “any storm that does develop has greater potential to develop into an intense storm.”
Hurricanes, typhoons, and rainstorms can in turn cause severe flooding, as can rising sea levels, which have been going up an average of 3.29 mm each year, reaching a new global peak in 2020.
One of the most dangerous consequences of rising quantities of evaporated sea water in the atmosphere is the increasing intensity of storms and hurricanes. “We can see now from the empirical data,” says Scott, “that hurricanes are behaving differently, they are going further inland where they then become rainstorm and flooding events. They dump a lot more water on the land because they’ve picked up more water [due to global warming] while they’ve been over the ocean.”
According to Scott, these natural hazards should alert more people to the fact that global warming is not just causing a steady rise in average temperatures. “Most people don’t fully understand the impact of climate change,” Scott says. “They hear the phrase ‘global warming’ and think, ‘Oh, everything is just getting a bit warmer, but it’s more complex than that.
“There is evidence that the changing climate is influencing the behavior of the jet stream, which has the effect of localizing weather systems for weeks at a time, causing prolonged rainfall, drought, frost or heat. Most climate scientists agree that over time, climate change will exacerbate chaotic severe weather events. Tropical storms will likely become more impactful, with higher wind-speeds, greater aerial extent, changing their typical paths and becoming extra tropical storms or rainstorm flooding events when they eventually hit land.”
The need for climate resilience
Even more sobering is the thought that there is no quick fix: even if the global community successfully meets the emissions targets outlined in the 2016 Paris Agreement, communities will still be feeling the effects of climate change, including natural hazards, for decades to come. This means that while tackling the causes of global warming we should also be trying to minimize its impact. This approach is known as climate resilience.
“When we talk about climate change,” explains Amar Rahman, Zurich’s Global Head of Climate Change Resilience Services, “we define the risk it presents in three dimensions: hazard, exposure and controls. People usually focus a lot on the hazards: there’s more rain, there’s more wind, there’s more heat. But we then develop models and scenarios to help them understand their exposure to those hazards, to identify their vulnerabilities or ‘pain points’. And then finally we assess the controls: what can you do to reduce and manage the impact of climate change right now? Climate resilience is about managing those three factors with the tools we have, and not waiting for new data or government regulation before you act. Because if you wait, it will be too late to develop solutions.”
One problem, one planet
When confronted by such a complex, long-term and wide-ranging crisis, it can be hard to know what to do and where to start. Hurricanes sweeping through the Caribbean, wildfires blazing for days in Australia and floodwaters threatening the coast of Bangladesh can feel like irresistible forces of nature beyond our individual control. Rahman, however, argues that you can adopt climate resilience as a personal strategy too. “I think a big part of the solution won’t come from governments or global organizations,” he says. “It will come from us, as individuals, as we change our behavior as consumers and voters.”
Counter-intuitively, one of the obstacles to reducing the impact of natural hazards made more severe by climate change is the sheer universality of the problem. Because global warming affects every continent, every country and indeed every person on the planet, it requires a truly coordinated global solution. This is hard to negotiate and achieve.
John Scott, however, sees a timely cause for optimism in the recent global response to the COVID-19 pandemic. “I think what COVID-19 has done is made people realize the importance of a global solutions to global risks,” he says, “and that what happens in one country can affect all countries. We need to harness existing solutions and all our innovation to mitigate greenhouse gas emissions and build climate resilience, as we did with the development of multiple COVID-19 vaccines in response to the pandemic.”