2021 Fulton County Environmental Scan

Environmental 

Introduction

Environmental problems by their nature are rarely purely local issues.  Air, water, habitat and climate do not recognize jurisdictional boundaries and cannot be effectively managed in isolation by individual local governments. Still, the magnitude of many current environmental issues require action at all levels of government.  This section discusses some of the most pressing environmental issues facing the planet today, particularly from the perspective of Fulton County and metro Atlanta, and explores some of the ways that local governments can play a role in addressing those issues.

Climate Change

Global annually averaged temperature increased by about 1.8°F (1.0°C) from 1901 to 2016, and by 1.2°F (0.65°C) for the period 1986–2015 as compared to 1901–1960. [1]  Sixteen of the last 17 years have been the warmest ever recorded by human observations.  While the magnitude and even the direction of changes brought about by a warming global climate vary by region, no area is immune from its effects.  The impact on our lives will be felt in various ways.  Higher temperatures, especially during the summer months, will likely bring about an increase in heat-related injuries and deaths as well as tax the electrical grid with higher peak demands.  Hotter weather along with changes in precipitation patterns could threaten water supplies.  Greater intensity in hurricanes and other extreme weather events will likely cause greater loss of life and property damage. Higher temperatures will also increase wildfire potential and complicate the management of controlled fires.  Sea-level rise, though typically viewed as a coastal problem, will also affect inland areas in the form of changing migration patterns--that is, the influx of climate migrants from coastal to inland cities.
Each of these impacts is discussed in the section below with emphasis on likely scenarios facing Fulton County and metro Atlanta.
Impacts
Heat
Both human activity and natural processes influence Earth’s climate, but the long-term global warming trend observed over the past century can only be explained by the effect that human activities have had on the climate. By far the most important of these activities in driving warming is the release of green house gases into the atmosphere.  Therefore, the results of models used to project future warming are highly dependent on assumptions regarding the degree to which emissions will be reduced or increased in coming decades.  Apart from those assumptions, there is a great deal of uncertainty in modeled projections due to an imperfect understanding of the interactions between climate and human and natural factors.  Nevertheless, great effort has been put into developing sophisticated climate models.  In 2021, a collaboration between a number of U.S. government agencies and universities combined 32 climate models to project climate change for each county in the U.S.  The models were run under two scenarios: a lower emission scenario in which humans stop increasing global emissions of heat-trapping gases by 2040 and then dramatically reduce them through 2100, and higher emission scenario in which global emissions of heat-trapping gases continue increasing through 2100. The average daily maximum temperature projected under both scenarios by mid-century is 76 degrees Fahrenheit, 4 degrees warmer than the observed average between 1961 and 1990. Projections under the two scenarios begin to diverge after mid-century.  At the end of the century, the average low emissions projection is 77.5 degrees while the average high emissions projection is 82 degrees.

As temperatures rise, heat-related injuries and deaths can be expected to rise as well, especially among older adults, pregnant women, children, outdoor workers, low income households, and people with chronic medical conditions. The effects of higher temperatures will be exacerbated in urban areas because of additional heat associated with urban heat islands. There is already evidence that heat waves are on the rise in the largest U.S. cities in terms of frequency, duration, and intensity [4]. As urban expansion continues, as is expected for the Atlanta metropolitan area, the effects of warming from the heat island effect could be nearly as great as that from global climate change [5].

Tropical Cyclones
Tropical cyclones are rapidly rotating storm systems characterized by a closed low-pressure center, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain.  Depending on its strength, a tropical cyclone in the Northern Atlantic Ocean basin is referred to as a depression, tropical storm or hurricane. 
Sophisticated computer models of these storms in a world with warming ocean waters indicate that, while the frequency of storms is not likely to change much, their intensity and the rate at which they intensify will increase [6].  It is also predicted that storms will carry more rain as they move inland and cause more flooding.
While Fulton County is far enough inland to be spared the full brunt of these storms, it is close enough to the the Atlantic and Gulf coasts to have suffered flooding, wind damage and casualties from the torrential rains and high winds these storms bring as well as from tornadoes that they often spawn.  Hurricanes that form in the Atlantic or Gulf of Mexico often move across Georgia, though almost always after being down-graded to a tropical storm or depression.  Nonetheless, they can still be destructive.  Since 1990, 35 storms, some originating as hurricanes, have tracked across the state of Georgia [2][3], including seven that passed through metro Atlanta. Two of these (Earl in 1998 and Michael in 2018) entered the state as hurricanes (wind speeds of at least 74 miles per hour). Seventeen entered as tropical storms (wind speeds of at least 39 miles per hours), and the reminder moved through the state as tropical depressions (under 39 mile per hour winds, but still capable unleashing tornadoes and dumping heavy rains).
Of the 35 named storms to track through Georgia since 1990, seven passed through metro Atlanta, or an average of about one every four years.  Numerous others passed close enough to have some impact.  As ocean water temperatures rise continue to rise, the storms that reach the metro area are increasingly likely be more intense as measured by wind speed and rainfall and to cause more damage than in the past.

Map 1. Tracks of cyclonic storms forming in the north Atlantic and Gulf of Mexico between 1990 and 2021. Southeastern states are most impacted by storms after making landfall from torrential rains and high winds.
Map 2. Tracks of the cyclonic storms whose centers passed through 0r near Georgia between 1990 and 2021.  The centers of 35 storms entered the states, two as hurricanes, the remainder as tropical storms or depressions.
Fire

Action
Resiliency Planning
Sustainability

[1] USGCRP, 2018: Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment, Volume II [Reidmiller, D.R., C.W. Avery, D.R. Easterling, K.E. Kunkel, K.L.M. Lewis, T.K. Maycock, and B.C. Stewart (eds.)]. U.S. Global Change Research Program, Washington, DC, USA, 1515 pp. doi: 10.7930/NCA4.2018.
[2] Knapp, K. R., M. C. Kruk, D. H. Levinson, H. J. Diamond, and C. J. Neumann, 2010: The International Best Track Archive for Climate Stewardship (IBTrACS): Unifying tropical cyclone best track data. Bulletin of the American Meteorological Society, 91, 363-376. doi:10.1175/2009BAMS2755.1
[3] Knapp, K. R., H. J. Diamond, J. P. Kossin, M. C. Kruk, C. J. Schreck, 2018: International Best Track Archive for Climate Stewardship (IBTrACS) Project, Version 4. [indicate subset used]. NOAA National Centers for Environmental Information. doi:10.25921/82ty-9e16 [access date].
[4] Habeeb, D., Vargo, J. & Stone, B. Rising heat wave trends in large US cities. Nat Hazards 76, 1651–1665 (2015). https://doi.org/10.1007/s11069-014-1563-z
[5] Kangning Huang et al 2019, Environ. Res. Lett. 14 114037. https://iopscience.iop.org/article/10.1088/1748-9326/ab4b71
[6] Bhatia, Kieran & Vecchi, Gabriel & Murakami, Hiroyuki & Underwood, Seth & Kossin, James. (2018). Projected Response of Tropical Cyclone Intensity and Intensification in a Global Climate Model. Journal of Climate. 31. 10.1175/JCLI-D-17-0898.1. https://www.researchgate.net/profile/Kieran-Bhatia/publication/326759021_Projected_Response_of_Tropical_Cyclone_Intensity_and_Intensification_in_a_Global_Climate_Model/links/5b9fc6ffa6fdccd3cb5ed9b4/Projected-Response-of-Tropical-Cyclone-Intensity-and-Intensification-in-a-Global-Climate-Model.pdf