An international team of scientists, including a Texas A&M University researcher, has conducted a study showing that models used to predict climate change may be not be accurate because they do not include sufficient data from past climates in their findings.
Yige Zhang, assistant professor in the Department of Oceanography, and fellow researchers have had their work published in the current issue of Science magazine.
The team found that past climate information — called paleoclimate — is not included in current studies and should be used to ensure accurate future climate predictions.
“We urge the climate model developer community to pay attention to the past and actively involve it in predicting the future,” says lead researcher Jessica Tierney of the University of Arizona. “If your model can simulate past climates accurately, it will likely do a much better job of getting future scenarios right.”
Zhang says historical weather data only goes back a few hundred years, “but we need millions of years in time to search for potential ‘analogs’ of our current day climate change.”
For decades, climate scientists have relied on weather records to compile their climate forecasts, using water temperatures, wind speeds, cloud formations, and other methods, including weather satellites.
But Zhang and the team found that, while these methods work well with some historical climates, they do not present a clear picture from Earth’s long-ago geological past.
Including past climate models may help us predict future events such as prolonged rainfall or loss of ice sheets, Zhang says.
“Paleoclimate is what has already happened, and we do not expect future climates to follow patterns exactly,” he says. “But paleoclimate studies can show us the important principles of how the Earth's climate system operates, which would be very insightful to predict future climate change.”
The study also found that greenhouse gases — especially carbon dioxide — are especially important in measuring past climate studies.
The researchers discovered that, while Earth’s atmosphere has experienced carbon dioxide levels much higher than today’s level of about 400 parts per million, there is no time in recorded history that matches the current speed at which humans are contributing to greenhouse gas emissions.
"The Earth has a rich history, and in particularly, climate history,” Zhang says. “There are 4.5 billion years for our disposal. Our study shows that the climate models that incorporate the knowledge obtained from paleoclimate will be better positioned to predict future climate change.”
The study was funded by NASA and the Heising-Simons Foundation.
