Global warming has contributed to some of this year's warmest recorded weather, melting polar ice caps, wildfires, and tropical storms. The National Oceanic and Atmospheric Administration (NOAA) released a forecast for the possible weather conditions this winter, including drought, dry winter in southern states, and wetter weather for northern states.
Drought expert David Miskus said that 45% of mainland USA is in drought, which is the highest level recorded in the past seven years. Mike Halpert said that the warmer and drier winters and cooled central Pacific area are the results of global weather patterns.
Northern states such as Washington, North Dakota, and Minnesota may get colder temperatures than normal this winter. Other northern states will have winter rain and snow and the central states will have normal weather conditions, said the NOAA.
Climate Change Affecting Drought
Climate change causes evapotranspiration, or water from land, water, and plants evaporating into the atmosphere due to warmer temperatures. As a result, dry areas experience drought through lower levels of lakes, rivers, and groundwater.
Agricultural areas lack enough moisture and food crops are largely affected. Even wetter areas may have prolonged dry seasons.
According to the Union of Concerned Scientists, semi-arid and desert areas are expected to expand due to an atmospheric pattern called the Hadley Cell. Tropical atmospheric circulation begins near the equator, flows to the subtropics at a low latitude, and back near the surface at the equator, affecting global trade winds and weather patterns.
Colder Winter in the North
Meanwhile, northern states are predicted to have a chillier winter due to the polar vortex. The low-pressure area in the North Pole contains swirling cold air. When it expands during the winter, the cold air travels south and causes outbreaks of cold temperatures in the United States.
Judah Cohen from Atmospheric Environmental Research predicts a harsher winter in the Northeast based on the activity in the Arctic. There may be heavy snowfall in eastern states as the polar vortex expands this winter. Although snowfall was light in Siberia at the beginning of October, it looks like there will be heavy snow cover by the end of the month, said Cohen.
According to NASA's Goddard Institute for Space Studies, the dry and wet weather patterns in the United States is a response to greenhouse gas emissions. Evidence of global warming affecting precipitation and drought was traced back to the early 1900s.
Ben Cook from the Goddard Institute said that global warming is not a problem in the future -- it is here and now. Patterns show how climate change is "already affecting global patterns of drought, hydroclimate, trends, variability." These trends are expected to continue and possibly worsen as the world keeps warming due to human activities.
Working with multiple climate models, all the data concluded that there would be a longer and more intense drought in the coming years. "Droughts will pose serious challenges to the safety, health, food and water supplies of plants, animals, and humans in some regions, and floods will do the same in others," wrote NASA.
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