Projections showing that global temperatures could increase by 7 degrees Fahrenheit during the next 100 years are accurate, two U researchers concluded in a study published earlier this month.
The study, which was published in the Bulletin of the American Meteorological Society, is based on research from U meteorologists Thomas Reichler and Junsu Kim.
Researchers compared about 50 past climate simulation models from the United States and other countries to conduct the study, which investigates how well those models can simulate the climate.
Kim said these models, which were developed over the course of the last 20 years, were analyzed to judge how well they were able to predict changes in the climate. The models use about 35 different variables to show a climate simulation, including temperature, humidity and wind.
“Since we do not have data of future climates, we thought it was a good idea to see how well these models compare with the observations of current data on the current climate,” Reichler said.
The researchers looked at climate simulations from several different models and combined those results with the model that most accurately predicted the climate. Reichler said that when you combine the simulations, the combined data is better than looking at any individual model alone.
“We can now use this information to use only the better models or weigh them higher,” Reichler said of future research in predicting climate change.
Reichler and Kim also looked at the most recent climate model from 2007 from the Intergovernmental Panel on Climate Change, and based on those observations, the researchers have more confidence in the accuracy of the projections than in past models.
Currently, U.S. models are the most accurate, which is the result of American efforts to build better models, Reichler said.
“U.S. models show very good performance,” Kim said. “U.S. models have very fine resolution compared to other models and are particularly good at looking at the northern hemisphere.”
Although the U.S. models are accurate, they do not account for unexpected occurrences, such as if humans were to begin greatly curbing gas emissions. However, the models could help researchers find better ways to slow global warming trends and call attention to the problem, Reichler said.
According to a 2006 Time magazine article, ocean waters have warmed by a full degree since 1970 because of global warming. This has led to inconsistent weather patterns, including an increased number of hurricanes than in previous generations. The report also warned that global warming can lead to more drought, the disappearance of snow packs and the possible extinction of polar bears because polar ice melts at a fast rate.
“Some people who don’t believe in climate change have argued that past models are not accurate enough to change our policies,” Reichler said. “This is partly true because past models were not as good, but now the models have reached a very high level. In simulating today’s climate, they do very good.”