As temperatures begin to plummet, you may be wondering – where the heck is global warming? Well, unfortunately, it’s still around.
First off, remember the difference between the terms “global warming” and “climate change”. “Global warming” was initially used by scientists because it describes how greenhouse gases trap heat in the atmosphere and warm the planet’s overall temperature. However, this temperature increase is one symptom of climate change – which includes melting land ice, changes in seasons, and sea level rise, among other things. Ultimately, climate change can be described as a shift towards extremes. Hurricanes become stronger, heavy rains become heavier, droughts last longer, heat waves are more intense, and cold snaps are also more severe. In the case of winter weather, snowstorms become stronger, dump more snow, and bring more cold. This shift towards extremes means more record-challenging snowfalls and cold temperatures this winter, and in winters to come.
Additionally, temperatures in the Arctic are warming, which causes shifts in the jet stream, an atmospheric pattern that is responsible for much of the weather in the United States. Warmer temperatures in the Arctic push the jet stream farther south, which brings frigid Arctic air further south and lingers there longer. This allows winter storms not only to be more severe, but to last longer as the jet stream’s swings tend to stay in place for a while. The jet stream could also slow, as it depends on temperature differences between the Arctic and tropical/equatorial regions. As the Arctic warms, the difference in temperature between these two regions becomes smaller, and because of this smaller difference, the jet stream will slow down. This is sometimes referred to as “atmospheric stagnation”, and it means that weather systems stay in place longer since they aren’t being carried away by the jet stream. So, a strong winter storm that stays in one area will continue to bring snow, wind, and cold weather until it finally gets carried away by the slower jet stream.
Fortunately, there are things you can do this winter to help mitigate the effects of climate change. Try keeping your house a little bit colder and not cranking up the heat too high. You can always put a sweatshirt, blanket, or a nice pair of fuzzy socks on to keep you warm, and the energy saved by this action will not only help the planet, but your wallet as well.
©2019 Meteorologist Margaret Orr
DISCUSSION: The Hawaiian island chain has shattered dozens of records regarding various temperatures since the late-Spring and extending into early Fall. Of note are ocean temperatures which, as recent as August 2019, had indicated temperatures as much as 3 degrees Fahrenheit higher than normal. This warmer than average oceanic temperature is expected to exacerbate coral bleaching, which appeared heavily in as recent as 2015.
Coral bleaching has been known to be a direct result of warm ocean temperatures, however not all events are due to this factor. According to the National Oceanic and Atmospheric Administration (NOAA), “when water is too warm, corals will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white.” Often during a coral bleaching event the coral is not dead, but is subject to intense strain and are thus susceptible to mortality. The state Division of Aquatic Resources (DAR) recently identified, areas of bleaching at Molokini and along the south shore from Makena to Maalaea. Certain species of coral in Molokini have already shown to be at or near 50% bleached.
If temperatures return to normal quickly, the likelihood of coral survival is increased, as it experiences decreased stress. Arizona State University Center for Global Discovery and Conservation Science (GDCS) has partnered with NOAA and DAR on coral reef science, conservation and management in Hawaii, offering programs such as the Pacific Ridge-to-Reef Initiative providing conservation and management practices that are bioculturally sustainable to ensure flourishing reefs in the future, by utilizing advanced aircraft satellite monitoring and modeling of reefs throughout Hawaii.
For more information on sea surface temperatures or coral bleaching events, visit the Global Weather and Climate Center!
© 2019 Meteorologist Jessica Olsen