Blog

New federal climate data raises questions about what’s normal

Out on Galveston, the effects of climate change are beyond obvious to Lisa Halili, CEO of Prestige Oyster in San Leon.

Oysters are dependent on specific levels of salinity in the water, about 14 parts per million, so any weather that makes the water become too salty, or not salty enough, is a problem, Halili said, and that’s exactly what warmer temperatures and drier weather do.

“We’re dealing with the effects of climate change every day,” she said. “It’s part of being in the oyster business.”

On Wednesday, Halili was asking for prayers for rain. The oysters need it, she said.

New data from the National Oceanic and Atmospheric Administration shows the Galveston region has gotten drier and warmer over the past 30 years, according to the Biden administration’s new “climate normals,” which are 30-year periods against which deviations from average are measured.

If the trend of a warming region continues, soon more than just the oyster industry might have to change the way they operate — cities could find themselves planning for more droughts, and workers will have to keep cool outside in the scorching heat.

A WARMER, DRIER ISLAND

The updated NOAA data shows the island’s average mean temperature through the day increased from 71.2 degrees to 72.3 degrees Fahrenheit over the past 30 years, an increase of about 1.1 degrees or 1.5 percent, said Jimmy Fowler, a meteorologist with the National Weather Service in League City.

As temperatures on the island have increased, Galveston also has seen less rain over the same period, Fowler said. The average annual precipitation has declined 3.54 inches, from 50.76 inches a year down to 47.22 inches, about a 7 percent decrease, he said.

“Not even looking at Galveston itself, but across the country, most sites have had an increase in the average temperature for the year” as compared to the 30-year period, Fowler said. “The effects of climate change are shown prevalently in the new normal. And, as we move into the next decade, that trend may continue.”

And it’s not just the island. While League City has seen more rain than Galveston, it’s also become warmer in recent years, Fowler said.

League City only had measured data from the most recent climate normal assessment, which shows it had an average annual precipitation of about 60.2 inches, Fowler said.

NOAA’s National Centers for Environmental Information at the end of each decade calculates the average new normal temperatures and precipitation amounts across the country, using weather data from the previous 30 years, Fowler said.

CLIMATE NORMALS

The climate normals were introduced by the World Meteorological Organization about 100 years ago to standardize weather information globally. A 30-year period is used to smooth out natural cycles that affect temperature and precipitation at different time scales.

The normals provide a recent historical context for measuring the magnitude of a heatwave or rainstorm, and can help predict conditions for a certain time or place. For example, the long-term historical average can give you a pretty good idea of what to pack if you’re planning a trip to San Francisco in mid-October. And the normals also are used to forecast river flows and to regulate power production, to time crop planting, and for construction planning and building design.

In the United States, the data come from about 8,700 weather stations. The recent update for the first time includes precipitation normals from 770 automated snow measurement sites and more than 5,400 citizen science observation stations. Precipitation has increased most notably in the Southeast and South Central United States.

NOAA officials said the update shows the United States overall has become warmer but not everywhere. The climate normal readings in the Northern Plains and the Upper Midwest for the latest period, 1991 to 2020, are cooler than those based on the data from 1981–2010, especially in the late winter and spring seasons. Longer-term, the Midwest is warming and projected to warm by at least 5 degrees Fahrenheit by 2100, according to a report from the Union of Concerned Scientists authored by Texas Tech University climate scientist Katharine Hayhoe.

THE BEST MEASURE?

The 30-year climate normals might provide a decent snapshot of recent historical conditions, but when the weather experts established the first climate normal period from 1901 to 1930, they weren’t anticipating the global climate would shift rapidly and inexorably in one direction.

At first, the updates were made simply to account for new weather stations added to the system, or for stations that were removed, said Mike Palecki, who led the National Ocean and Atmospheric Administration team that compiled the data. “But the climate normals are not the best way to measure global warming,” he said. “It kind of mutes the signal a little bit.”

A day that might have been exceptionally warm for a given season back in 1950 now “looks normal because we’ve moved the baseline,” he said. But the 30-year reference periods are still useful because they let us compare today’s weather with “normal weather” on a relevant timescale.

For example, the normals can help a construction company plan a project knowing about how many days of rain or hot temperatures to expect, on average, during July and August at a given location, he said. The normals offer a framework for making forecasts that are beyond the range of short-term weather models but not in the scope of climate change projections.

Some climatologists say the switch to the latest reference period, based on data from 1991 to 2020, makes it harder to explain to the public how fast the climate is changing right now.

In the era of rapid human-caused warming, it might be worth rethinking the concept of normals, at least for public climate communications, said Özden Terli, a broadcast meteorologist with ZDF, one of the main German television networks and a member of Climate Without Borders, a global network of weather presenters focusing on communicating scientific climate change information.

The previous climate normal reference period (1981 to 2010) was “relatively far in the past, but now we’re fully in the fast warming phase,” he said. “When you say the temperature is 0.2 degrees Celsius above normal, and you’re using that new climate period as the reference, it kind of hides some of the previous warming.”

To fully communicate how much greenhouse gas pollution has warmed the planet, it would be best to use a climate reference period from the pre-industrial era, before about 1850, he said. But many countries don’t have extensive and accurate records going back that far, so it’s not a useful reference for some purposes.

Some experts have advocated for using the 1961 to 1990 period because it was a relatively stable period during the modern climate era, Terli said. But global warming has accelerated so much since the 1980s that the average data from the decades since then don’t fit into any historical climate context, he said.

CORE PROBLEM

And that’s the core of the problem, said Tobias Schad, a Berlin-based meteorologist working on forest health issues.

“When you compare today’s temperatures against a reference period that includes so many hot years, some people might think, ‘Oh, it’s not so bad,’ so, through the back door, there is a normalization of warming,” he said.

“And it’s also a problem that skeptics, or climate deniers, could use it to say it’s not warming dangerously, which is bad at a time when it’s more important than ever to show people that we are coming out of a stable climate, and that we are in an unstable climate.”

Robert Rohde, lead climate scientist at Berkeley Earth, said, “I’m not a fan. That we call them ‘normals’ often makes communication worse, in my opinion. The concept of a 30-year baseline is not inherently terrible, but ‘normalizing’ the recent past as the frame of reference can hinder understanding of the important longer-term changes,” he said.

“I think we almost all understand that there no longer is a normal climate,” said physicist Nick Cowern, emeritus professor at the Newcastle University School of Engineering. “It’s better to look at dynamic change, which is what actually affects us, or to compare to the preindustrial climate to understand how far we are from equilibrium and civilisational stability,” he said.

“Shifting baselines are bad,” added Stefan Rahmstorf, a climate scientist at the Potsdam Institute for Climate Impact Research. “They obscure climate change.”

CLIMATE CHANGE FOCUS

The issue of climate change has historically been a dividing issue for residents in the northern parts of Galveston County, League City Councilman Larry Millican said.

But evidence such as the climate normal, combined with the onslaught of rare hurricanes and bad weather in recent years, has placed new attention on the city’s plans for the future, Millican said.

“In the 70 years that I’ve been around, people are paying more attention to flooding now than ever before,” Millican said.

And it’s not just flooding, Millican said. City officials for years have been planning for how to handle rapid population growth in a future where water sources might become scarcer.

“It’s one of our single biggest needs moving forward,” City Manager John Baumgartner said in 2018.

WORKING OUTSIDE

Thus far, rising temperatures haven’t been enough to force Galveston County contractors accustomed to hot summer weather to adjust their schedules, said Jay Wilson, owner of Wilson Construction in Galveston.

“I guess maybe it will at some point,” Wilson said. “But most of the crews I use haven’t adjusted at this point. Even though it’s a bit warmer, it’s still bearable.”

The same is largely true in the landscaping business, said Greg Gripon, owner of League City-based Lynn’s Landscaping. Some residents have sought out drought-tolerant landscaping, but the vast majority have not thus far.

“Most people have sprinkler systems and don’t tend to worry,” he said.

“Most people way overwater their palm trees,” Gripon said.

Matt deGrood: 409-683-5230; matt.degrood@galvnews.com.

Leave a Reply

Your email address will not be published. Required fields are marked *