Last summer, Austin created an electricity bill assistance program to deal with exceptionally high power bills related to extreme temperatures.
The city Web site has tips for keeping cool during the summer, reminding citizens that it can be helpful to submerge body parts in buckets of water to prevent overheating.
When I moved here, an Austinite friend of mine warned me not to judge the city until about October, when the weather can safely be considered tolerable. I’ve still spent a good part of the past few weeks wrapped in blankets and howling about the cold to anyone who will listen.
Droughts and floods, hot and cold, air conditioners and heaters working in the same day: Weather can get challenging in Austin and in many other places in the world. As someone who studies climate, I am usually very careful to distinguish between weather and climate. Weather deals with short-term fluctuations, while climate is a more fundamental characteristic — often more stable and predictable.
Spring turning to summer is not an indicator of climate change, and neither is our inability to accurately predict daily weather patterns more than a few weeks ahead indicative of an inability to recognize a changing climate. That said, extreme weather represents an important chance to relate weather and climate change.
Talking about a potential 5-degree (Fahrenheit) increase in average global temperature from anthropogenic climate change might not sound that bad. Temperatures fluctuate by more than that on a daily — even hourly — basis. Many of the risks of climate change lie in the altered system characteristics that an increased average temperature fosters: changing habitats, changing precipitation patterns, rising sea levels and the like.
Often, projections suggest that extremes will be exacerbated. Dry areas will likely get drier, wet areas wetter, hot areas hotter — and hot days hotter.
Adding 5 degrees to the temperature on days of extreme heat can be dangerous to living and engineered systems. The European heat wave of 2003 notoriously killed tens of thousands of people as a result of extreme temperatures, notably from hyperthermia and fires.
Though humans, animals and plants are often surprisingly resilient in the face of stresses, single extreme events can prove deadly. We may be able to survive for weeks without food, but a few hours above a temperature threshold will kill us. Crops subjected to a week or two of above normal temperatures can die, and warm waters can destroy fish hatcheries. Much as small concentrations of greenhouse gases can create a large temperature effect, a small amount of exposure to extreme conditions can have disproportionate impacts on well-being.
Extreme temperatures also hurt our ability to protect ourselves. Across the world, large power plants have either shut down or come very close to shutting down because cooling water was not cool enough during times of extreme heat. This is particularly problematic because power for air conditioning and other services is especially needed during extreme temperature events.
Even when industrial cooling is not a problem, extreme temperatures can create demand for electricity that exceeds our ability to provide it, leading to blackouts that further exacerbate the problem.
Our development patterns can make us more vulnerable to extreme conditions. The world is becoming more urban, and the trend is expected to continue. For many characteristics, urbanization actually reduces human pressures on the environment by consolidating our footprint.
If not carefully planned, however, urbanization can magnify the risk posed by extreme-heat events. The urban heat island phenomenon, born of the tendency of buildings and paved surfaces to trap heat, is well documented. Many building materials are effective thermal masses, retaining more heat than undeveloped regions, and waste heat from industry and other processes can also be a factor in some areas. Green space and attentiveness to the heat reflectivity of roofs and paved surfaces can lessen the problem, but they must be actively incorporated.
Climate change poses major risks to habitats, human settlements and human activities, and it is a direct health threat in the case of extreme events. We may joke during cold periods that a 5-degree boost to temperatures would make life a lot easier, but it’s sobering to realize that the same 5-degree boost might occur when we’re sitting with our feet in buckets of water during a summer power outage. Austin is no stranger to extreme weather, and we may soon have a lot more company as other cities learn what extreme heat means.