Climate Change Contexts: Global, National, and State
Located in the middle of the United States, Nebraska receives minimal climate moderation from the oceans, something that is unlike other states. As a result, the weather can experience large swings from day-to-day and season to season. In the eastern part of the state, humid conditions prevail, while in the western part, semi-arid conditions are prevalent. The state as a whole typically has humid summers and cold winters.
Nebraska has climate hazards like severe thunderstorms, tornadoes, hail, flooding rains, droughts, heat waves, and blizzards. With climate change increasing the intensity of climate hazards, there is an expected increase in frequency and severity of events that will impact crop yields, displace communities, damage infrastructure, and disrupt tourism. Some impacts include an increased vulnerability to wildfires, invasive species, reduced air quality, and shifts in disease patterns.
Climate Change in a Historical Context
Climate change in itself is a natural phenomenon, however, the rate at which it is occurring is alarming. Current rates are roughly 10 times faster than the average rate of warming since the last Ice Age. This acceleration in the changing of the global climate stems from the excess production of greenhouse gases like carbon dioxide, methane, and nitrous oxide from human activities. Average global temperatures have risen about 2°F since the pre-industrial era. Although seemingly a slight increase in global temperatures, these changes can drastically alter natural processes and temperature and precipitation extremes.
The term "global warming" generally refers to the trend of global rising temperatures, but this trend is not occurring equally across every region. While most regions are experiencing warming temperatures, isolated parts of the world are also experiencing a cooling phenomenon. Globally, especially with coastal regions, oceans play a major role in regulating temperatures. The oceans store a big portion of carbon dioxide, preventing it from being released into the atmosphere, where it would trap even more heat. With increasing global temperatures, however, the ocean's capacity to store carbon dioxide decreases, which ultimately reduces its temperature-regulating abilities.
Current Climate Phenomenon
With more heat being trapped in the atmosphere, there is less snow and ice, higher sea level rise, increases in ocean heat content, changes in rainfall patterns, and higher humidity. In northern states specifically, winters are becoming shorter. East of the Rocky Mountains, temperatures in the summer have decreased. Moreover, the number of frost-free days is increasing, which is important in agricultural states like Nebraska in determining the potential growing season. The increasing length of frost-free days means the growing season is also increasing. Global rainfall has increased with a trend of the eastern United States getting wetter, while the southwest is getting drier. Similarly, snow cover is declining globally, especially in the spring. The Mississippi Basin, which Nebraska is a part of, is having snow loss at 5% to 6% per decade since 1980, meaning increased water shortages and increasing frequency of drought-related issues. In addition, the frequency and intensity of extreme heat events have increased. Inversely, the frequency of extreme cold events has decreased. The number of cold days, considered when the temperature is less than or equal to 32°F, has decreased throughout the country, except in the southeast.
Global Climate
On a global scale, there is an increasing trend of droughts on all continents. This trend is related to the increasing atmospheric demand due to higher temperatures rather than decreases in precipitation. The combination of higher temperatures and drier conditions has produced an increased frequency, severity, and prolonged periods of wildfires. This is especially problematic with wildfires releasing billions of tons of carbon dioxide into the atmosphere. Wildfires also cause billions of dollars in property damage and leave people and ecosystems at increased vulnerability. Regarding tornadoes, "Tornado Alley" is seeing an eastward shift in the United States, with research finding a decreasing trend of tornado events but having more tornado sightings per event.
