A pedestrian uses an umbrella to get out of the sun as she walks past a sign showing the temperature on June 20, 2017 in Phoenix, Arizona. Ralph Freso / Getty Images hide the caption
Ralph Freso / Getty Images
Ralph Freso / Getty Images
It has become so common that you may not have noticed how often your local weather forecast is “above normal”. It is extremely hot in summer. It is when mild temperatures persist throughout the winter. It’s when the nights don’t cool down as they used to.
But on May 4th, the hotter earth will officially become the new normal.
At this point in time, the National Oceanic and Atmospheric Administration (NOAA) publishes its once a decade update on “Climate Normals”. These are the 30-year averages for temperature and precipitation that local meteorologists use as the basis for their forecasts. Of course, some updates will be tiny. But the fastest warming locations will see a real spike in their averages that could make some projections confusing and could pose a challenge to weather forecasters.
The current “normals” date from 1981 to 2010 and are based on data collected from thousands of monitoring stations across the country operated by the National Weather Service. The NOAA update will later move the timeframe for these averages to 1991-2020. The decade from 2011 to 2020 is one of the hottest in the US
“There has been a very clear upward trend in temperatures, especially along the west coast, south and east coast,” said Mike Palecki of NOAA’s National Environmental Information Centers.
There were exceptions; Some places in the northern United States have actually cooled off a bit. But globally, the last decade that ended in 2020 was the hottest decade ever recorded since 1880.
In Phoenix, Amber Sullins, chief meteorologist at ABC 15, has seen rising heat in her hometown throughout her life. Part of this is the urban heat island effect, as the city’s expanding concrete terrain stores more heat overnight. However, the most recent national climate assessment found that greenhouse gases from human activity are increasing heat waves and aggravating periods of drought, with some of the highest temperature increases being seen in the southwest.
Sullins says last summer was particularly brutal.
“We set a record of 53 days at 110 degrees or hotter. The previous record was 33 days, so it wasn’t even close,” she says. Additionally, Sullins said Phoenix hasn’t set a single record for low temperatures in all of the last decade.
After the NOAA update in May, which set the basis for the normal transition to higher temperatures, forecasters in Phoenix and many other locations may no longer be pointing to as many “above average” days as before. In fact, some days that are now considered warm may officially get “cooler” when compared to the new temperature average. Sullins plans to take more time in her daily forecasts to explain the shift.
“We need to remind people, especially this year, ‘Hey, when we’re 115 it’s 5 degrees above average. But remember, that average has changed,” she says.
A “slow grind” with a big impact
This context is important. Research shows that when unusual weather events occur more frequently, people simply reset their perception of what is normal. One study found that a common reference point for “normal conditions” was only 2-8 years ago.
Frances Moore, co-author of the study and professor of environmental policy at the University of California at Davis, has seen this rate of “normalization” in her own state. After 5 years of extreme smoke from forest fires, she says that now people are just saying, “Oh, fire season is coming, I think we’d better prepare for it.”
“We don’t know how much warming happens on a regular basis,” says Bernadette Woods Placky, chief meteorologist at the nonprofit Climate Central. “It’s this slow grinding that eats up the changing normal that sometimes doesn’t allow you to sit back and see what it used to be.”
The earth has warmed 2 degrees Fahrenheit since the middle of the 20th century, and the rate of that warming has increased over the past few decades. Scientists warn that humans must prevent global temperatures from rising more than 3 degrees Fahrenheit in order to avoid the most catastrophic effects of climate change.
However, for many, the once a decade update of their local temperature averages is unlikely to impress, if they even notice.
“A degree warming doesn’t sound like much to most people. In fact, people say,” Oh, great, I can cook more more often in December, “said Marshall Shepherd, director of atmospheric science at the University of Georgia.
Yet long-term warming is so important that he wonders whether it is confusing to use the term “normal” at all.
Woods Placky is working with local weather forecasters to help them identify this change. This year’s update is an opportunity to explain what has happened not only in the last 10 years, “the 10 years before and 10 years before, and see how these changes build in full.” Picture.”
Shepherd hopes meteorologists and other media outlets will also explain what warming means to people’s lives. For one, it has helped fuel the increasingly extreme forest fires, floods and hurricanes that more and more people are enduring. He says a hotter climate also has more subtle consequences, such as rising food prices, falling water supplies, and the spread of vector-borne diseases.
“It’s about things that are affecting your kitchen table problems, paperback, livelihood, and health right now,” says Shepherd.
Many industries are also feeling the brunt of the changing climate, and for them the official 30-year weather average is becoming less relevant.
According to NOAA’s Palecki, companies want newer data that reflects the risks they are now facing. Energy companies and utilities, for example, need a precise feel for extreme heat and cold in order to calculate electricity demand and tariff changes. The recent power outages in Texas have shown the stakes. Weather forecasts are also key to contracting construction companies.
“They want to know how many days it rains in a certain period of time, so they have a certain number of rainy days to incorporate into their plans,” says Palecki.
To help companies prepare better, for the first time this year, NOAA will also publish 15-year averages using more recent temperature and rainfall data. This is one of many ways the agency is helping people keep pace with a “normal” climate that is constantly changing.