Hot summers have started to feel like a new normal for Portland. Long, dry days are becoming more and more frequent as the years go by. For the last three years, over 80 summer days have had high temperatures over 80 degrees. But what is this change due to?
Average temperatures in Portland have increased by over four degrees since 1940. While this may not seem like a drastic change, it severely affects the climate, increasing the risk of droughts, floods, rising sea levels, and heat waves. It also can lead to a loss of biodiversity and the extinction of species.
Most fluctuations in heat are due to the carbon dioxide emissions trapped in the atmosphere. The carbon is engulfed in the sun’s heat, reflecting it down to earth. This process, known as the greenhouse effect, has only gotten worse in the past century. As industrialization becomes more common throughout the world, more gasses are released into the sky, increasing the effect on the planet. Unless emission levels decline significantly in the near future, the impacts of global warming and climate change will only grow.
Climate change not only affects the summer temperatures but increases the extremity of many winter weather patterns. “20 years ago, we maybe had a couple of normal snow days…we didn’t have six plus days of ice storms,” said Julieanne Quigley, a chemistry and biology teacher at Ida B. Wells-Barnett High School.
Global warming also affects the length of fire season, which has been a recurring problem in Oregon recently. “It would be so difficult to have to deal with a fire epidemic like we had in 2020. The skies were all red, and it was so hard to breathe with all the smoke in the air,” said Elise Norman, a sophomore at IBW.
Furthermore, big cities such as Portland can experience what is known as the “urban heat island effect.” This occurs when big cities start to replace natural features of the land, such as forests or rivers, with the construction of buildings or pavement. Lack of tree coverage, along with the tendency of these surfaces to trap or absorb heat, leads to increased temperatures in cities. Many people have experienced this effect before by feeling asphalt on a hot summer day.
However, there are many other reasons for weather changes, one of which is the climate pattern known as La Niña, or “little girl” in Spanish. La Niña is a part of the El Niño Southern Oscillation (ENSO), which measures changes in temperature and pressure in the atmosphere and oceans. La Niña is one of these changes, described as cooling the ocean’s surface.
La Niña typically lasts a few years, and its effects range from mild to serious. For the Pacific Northwest (PNW), it brings excessive rain and flooding, but for the southern United States, it can lead to increased droughts and risk of hurricanes. 2024 is expected to be a La Niña year and develop between June and August, so what does this mean for Portland?
For the PNW, La Niña brings cooler temperatures and less risk of hurricanes, due to the strong vertical wind gusts. However, states outside of the hurricane zones are anticipated to experience high temperatures and less precipitation than normal, meaning Portland is heading toward a hot summer.
Although we cannot reverse the effects of La Niña, global warming has been proven to significantly worsen the La Niña weather cycle. “I do think we can probably make the problem worse by [increasing] pollution [levels] and increasing CO2,” said Quigley.
It’s important to understand how much worse global warming makes the climate, and how fast it’s changing. Even if you don’t think it’ll make much of a difference, it’s worth it to educate yourself and others and limit your emissions.
